Adding upstream version 1:10.11.6.upstream/1%10.11.6

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 17676 insertions, 0 deletions

diff --git a/storage/innobase/dict/dict0boot.cc b/storage/innobase/dict/dict0boot.cc
new file mode 100644
index 00000000..5516bce9
--- /dev/null
+++ b/storage/innobase/dict/dict0boot.cc
@@ -0,0 +1,440 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2016, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file dict/dict0boot.cc
+Data dictionary creation and booting
+
+Created 4/18/1996 Heikki Tuuri
+*******************************************************/
+
+#include "dict0boot.h"
+#include "dict0crea.h"
+#include "btr0btr.h"
+#include "dict0load.h"
+#include "trx0trx.h"
+#include "srv0srv.h"
+#include "ibuf0ibuf.h"
+#include "buf0flu.h"
+#include "log0recv.h"
+#include "os0file.h"
+
+/** The DICT_HDR page identifier */
+static constexpr page_id_t hdr_page_id{DICT_HDR_SPACE, DICT_HDR_PAGE_NO};
+
+/** @return the DICT_HDR block, x-latched */
+static buf_block_t *dict_hdr_get(mtr_t *mtr)
+{
+  /* We assume that the DICT_HDR page is always readable and available. */
+  return buf_page_get_gen(hdr_page_id, 0, RW_X_LATCH, nullptr, BUF_GET, mtr);
+}
+
+/**********************************************************************//**
+Returns a new table, index, or space id. */
+void
+dict_hdr_get_new_id(
+/*================*/
+	table_id_t*		table_id,	/*!< out: table id
+						(not assigned if NULL) */
+	index_id_t*		index_id,	/*!< out: index id
+						(not assigned if NULL) */
+	uint32_t*		space_id)	/*!< out: space id
+						(not assigned if NULL) */
+{
+	ib_id_t		id;
+	mtr_t		mtr;
+
+	mtr.start();
+	buf_block_t* dict_hdr = dict_hdr_get(&mtr);
+
+	if (table_id) {
+		id = mach_read_from_8(DICT_HDR + DICT_HDR_TABLE_ID
+				      + dict_hdr->page.frame);
+		id++;
+		mtr.write<8>(*dict_hdr, DICT_HDR + DICT_HDR_TABLE_ID
+			     + dict_hdr->page.frame, id);
+		*table_id = id;
+	}
+
+	if (index_id) {
+		id = mach_read_from_8(DICT_HDR + DICT_HDR_INDEX_ID
+				      + dict_hdr->page.frame);
+		id++;
+		mtr.write<8>(*dict_hdr, DICT_HDR + DICT_HDR_INDEX_ID
+			     + dict_hdr->page.frame, id);
+		*index_id = id;
+	}
+
+	if (space_id) {
+		*space_id = mach_read_from_4(DICT_HDR + DICT_HDR_MAX_SPACE_ID
+					     + dict_hdr->page.frame);
+		if (fil_assign_new_space_id(space_id)) {
+			mtr.write<4>(*dict_hdr,
+				     DICT_HDR + DICT_HDR_MAX_SPACE_ID
+				     + dict_hdr->page.frame, *space_id);
+		}
+	}
+
+	mtr.commit();
+}
+
+/** Update dict_sys.row_id in the dictionary header file page. */
+void dict_hdr_flush_row_id(row_id_t id)
+{
+  mtr_t mtr;
+  mtr.start();
+  buf_block_t* d= dict_hdr_get(&mtr);
+  byte *row_id= DICT_HDR + DICT_HDR_ROW_ID + d->page.frame;
+  if (mach_read_from_8(row_id) < id)
+    mtr.write<8>(*d, row_id, id);
+  mtr.commit();
+}
+
+/** Create the DICT_HDR page on database initialization.
+@return error code */
+dberr_t dict_create()
+{
+	ulint		root_page_no;
+
+	dberr_t err;
+	mtr_t mtr;
+	mtr.start();
+	compile_time_assert(DICT_HDR_SPACE == 0);
+
+	/* Create the dictionary header file block in a new, allocated file
+	segment in the system tablespace */
+	buf_block_t* d = fseg_create(fil_system.sys_space,
+				     DICT_HDR + DICT_HDR_FSEG_HEADER, &mtr,
+                                     &err);
+	if (!d) {
+		goto func_exit;
+	}
+	ut_a(d->page.id() == hdr_page_id);
+
+	/* Start counting row, table, index, and tree ids from
+	DICT_HDR_FIRST_ID */
+	mtr.write<8>(*d, DICT_HDR + DICT_HDR_ROW_ID + d->page.frame,
+		     DICT_HDR_FIRST_ID);
+	mtr.write<8>(*d, DICT_HDR + DICT_HDR_TABLE_ID + d->page.frame,
+		     DICT_HDR_FIRST_ID);
+	mtr.write<8>(*d, DICT_HDR + DICT_HDR_INDEX_ID + d->page.frame,
+		     DICT_HDR_FIRST_ID);
+
+	ut_ad(!mach_read_from_4(DICT_HDR + DICT_HDR_MAX_SPACE_ID
+				+ d->page.frame));
+
+	/* Obsolete, but we must initialize it anyway. */
+	mtr.write<4>(*d, DICT_HDR + DICT_HDR_MIX_ID_LOW + d->page.frame,
+		     DICT_HDR_FIRST_ID);
+
+	/* Create the B-tree roots for the clustered indexes of the basic
+	system tables */
+
+	/*--------------------------*/
+	root_page_no = btr_create(DICT_CLUSTERED | DICT_UNIQUE,
+				  fil_system.sys_space, DICT_TABLES_ID,
+				  nullptr, &mtr, &err);
+	if (root_page_no == FIL_NULL) {
+		goto func_exit;
+	}
+
+	mtr.write<4>(*d, DICT_HDR + DICT_HDR_TABLES + d->page.frame,
+		     root_page_no);
+	/*--------------------------*/
+	root_page_no = btr_create(DICT_UNIQUE,
+				  fil_system.sys_space, DICT_TABLE_IDS_ID,
+				  nullptr, &mtr, &err);
+	if (root_page_no == FIL_NULL) {
+		goto func_exit;
+	}
+
+	mtr.write<4>(*d, DICT_HDR + DICT_HDR_TABLE_IDS + d->page.frame,
+		     root_page_no);
+	/*--------------------------*/
+	root_page_no = btr_create(DICT_CLUSTERED | DICT_UNIQUE,
+				  fil_system.sys_space, DICT_COLUMNS_ID,
+				  nullptr, &mtr, &err);
+	if (root_page_no == FIL_NULL) {
+		goto func_exit;
+	}
+
+	mtr.write<4>(*d, DICT_HDR + DICT_HDR_COLUMNS + d->page.frame,
+		     root_page_no);
+	/*--------------------------*/
+	root_page_no = btr_create(DICT_CLUSTERED | DICT_UNIQUE,
+				  fil_system.sys_space, DICT_INDEXES_ID,
+				  nullptr, &mtr, &err);
+	if (root_page_no == FIL_NULL) {
+		goto func_exit;
+	}
+
+	mtr.write<4>(*d, DICT_HDR + DICT_HDR_INDEXES + d->page.frame,
+		     root_page_no);
+	/*--------------------------*/
+	root_page_no = btr_create(DICT_CLUSTERED | DICT_UNIQUE,
+				  fil_system.sys_space, DICT_FIELDS_ID,
+				  nullptr, &mtr, &err);
+	if (root_page_no == FIL_NULL) {
+		goto func_exit;
+	}
+
+	mtr.write<4>(*d, DICT_HDR + DICT_HDR_FIELDS + d->page.frame,
+		     root_page_no);
+func_exit:
+	mtr.commit();
+	return err ? err : dict_boot();
+}
+
+/*****************************************************************//**
+Initializes the data dictionary memory structures when the database is
+started. This function is also called when the data dictionary is created.
+@return DB_SUCCESS or error code. */
+dberr_t dict_boot()
+{
+	dict_table_t*	table;
+	dict_index_t*	index;
+	mem_heap_t*	heap;
+	mtr_t		mtr;
+
+	static_assert(DICT_NUM_COLS__SYS_TABLES == 8, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_TABLES == 10, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_TABLE_IDS == 2, "compatibility");
+	static_assert(DICT_NUM_COLS__SYS_COLUMNS == 7, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_COLUMNS == 9, "compatibility");
+	static_assert(DICT_NUM_COLS__SYS_INDEXES == 8, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_INDEXES == 10, "compatibility");
+	static_assert(DICT_NUM_COLS__SYS_FIELDS == 3, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_FIELDS == 5, "compatibility");
+	static_assert(DICT_NUM_COLS__SYS_FOREIGN == 4, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_FOREIGN == 6, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_FOREIGN_FOR_NAME == 2,
+		      "compatibility");
+	static_assert(DICT_NUM_COLS__SYS_FOREIGN_COLS == 4, "compatibility");
+	static_assert(DICT_NUM_FIELDS__SYS_FOREIGN_COLS == 6, "compatibility");
+
+	mtr.start();
+	/* Create the hash tables etc. */
+	dict_sys.create();
+
+	dberr_t err;
+	const buf_block_t *d = buf_page_get_gen(hdr_page_id, 0, RW_X_LATCH,
+						nullptr, BUF_GET, &mtr, &err);
+        if (!d) {
+		mtr.commit();
+		return err;
+        }
+
+	heap = mem_heap_create(450);
+
+	dict_sys.lock(SRW_LOCK_CALL);
+
+	const byte* dict_hdr = &d->page.frame[DICT_HDR];
+
+	/* Because we only write new row ids to disk-based data structure
+	(dictionary header) when it is divisible by
+	DICT_HDR_ROW_ID_WRITE_MARGIN, in recovery we will not recover
+	the latest value of the row id counter. Therefore we advance
+	the counter at the database startup to avoid overlapping values.
+	Note that when a user after database startup first time asks for
+	a new row id, then because the counter is now divisible by
+	..._MARGIN, it will immediately be updated to the disk-based
+	header. */
+
+	dict_sys.recover_row_id(mach_read_from_8(dict_hdr + DICT_HDR_ROW_ID));
+	if (uint32_t max_space_id
+	    = mach_read_from_4(dict_hdr + DICT_HDR_MAX_SPACE_ID)) {
+		max_space_id--;
+		fil_assign_new_space_id(&max_space_id);
+	}
+
+	/* Insert into the dictionary cache the descriptions of the basic
+	system tables */
+	/*-------------------------*/
+	table = dict_table_t::create(dict_sys.SYS_TABLE[dict_sys.SYS_TABLES],
+				     fil_system.sys_space,
+				     DICT_NUM_COLS__SYS_TABLES, 0, 0, 0);
+	dict_mem_table_add_col(table, heap, "NAME", DATA_BINARY, 0,
+			       MAX_FULL_NAME_LEN);
+	dict_mem_table_add_col(table, heap, "ID", DATA_BINARY, 0, 8);
+	/* ROW_FORMAT = (N_COLS >> 31) ? COMPACT : REDUNDANT */
+	dict_mem_table_add_col(table, heap, "N_COLS", DATA_INT, 0, 4);
+	/* The low order bit of TYPE is always set to 1.  If ROW_FORMAT
+	is not REDUNDANT or COMPACT, this field matches table->flags. */
+	dict_mem_table_add_col(table, heap, "TYPE", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "MIX_ID", DATA_BINARY, 0, 0);
+	/* MIX_LEN may contain additional table flags when
+	ROW_FORMAT!=REDUNDANT. */
+	dict_mem_table_add_col(table, heap, "MIX_LEN", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "CLUSTER_NAME", DATA_BINARY, 0, 0);
+	dict_mem_table_add_col(table, heap, "SPACE", DATA_INT, 0, 4);
+
+	table->id = DICT_TABLES_ID;
+
+	dict_table_add_system_columns(table, heap);
+	table->add_to_cache();
+	dict_sys.sys_tables = table;
+	mem_heap_empty(heap);
+
+	index = dict_mem_index_create(table, "CLUST_IND",
+				      DICT_UNIQUE | DICT_CLUSTERED, 1);
+
+	dict_mem_index_add_field(index, "NAME", 0);
+
+	index->id = DICT_TABLES_ID;
+	err = dict_index_add_to_cache(
+		index, mach_read_from_4(dict_hdr + DICT_HDR_TABLES));
+	ut_a(err == DB_SUCCESS);
+	ut_ad(!table->is_instant());
+	table->indexes.start->n_core_null_bytes = static_cast<uint8_t>(
+		UT_BITS_IN_BYTES(unsigned(table->indexes.start->n_nullable)));
+
+	/*-------------------------*/
+	index = dict_mem_index_create(table, "ID_IND", DICT_UNIQUE, 1);
+	dict_mem_index_add_field(index, "ID", 0);
+
+	index->id = DICT_TABLE_IDS_ID;
+	err = dict_index_add_to_cache(
+		index, mach_read_from_4(dict_hdr + DICT_HDR_TABLE_IDS));
+	ut_a(err == DB_SUCCESS);
+
+	/*-------------------------*/
+	table = dict_table_t::create(dict_sys.SYS_TABLE[dict_sys.SYS_COLUMNS],
+				     fil_system.sys_space,
+				     DICT_NUM_COLS__SYS_COLUMNS, 0, 0, 0);
+	dict_mem_table_add_col(table, heap, "TABLE_ID", DATA_BINARY, 0, 8);
+	dict_mem_table_add_col(table, heap, "POS", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "NAME", DATA_BINARY, 0, 0);
+	dict_mem_table_add_col(table, heap, "MTYPE", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "PRTYPE", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "LEN", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "PREC", DATA_INT, 0, 4);
+
+	table->id = DICT_COLUMNS_ID;
+
+	dict_table_add_system_columns(table, heap);
+	table->add_to_cache();
+	dict_sys.sys_columns = table;
+	mem_heap_empty(heap);
+
+	index = dict_mem_index_create(table, "CLUST_IND",
+				      DICT_UNIQUE | DICT_CLUSTERED, 2);
+
+	dict_mem_index_add_field(index, "TABLE_ID", 0);
+	dict_mem_index_add_field(index, "POS", 0);
+
+	index->id = DICT_COLUMNS_ID;
+	err = dict_index_add_to_cache(
+		index, mach_read_from_4(dict_hdr + DICT_HDR_COLUMNS));
+	ut_a(err == DB_SUCCESS);
+	ut_ad(!table->is_instant());
+	table->indexes.start->n_core_null_bytes = static_cast<uint8_t>(
+		UT_BITS_IN_BYTES(unsigned(table->indexes.start->n_nullable)));
+
+	/*-------------------------*/
+	table = dict_table_t::create(dict_sys.SYS_TABLE[dict_sys.SYS_INDEXES],
+				     fil_system.sys_space,
+				     DICT_NUM_COLS__SYS_INDEXES, 0, 0, 0);
+
+	dict_mem_table_add_col(table, heap, "TABLE_ID", DATA_BINARY, 0, 8);
+	dict_mem_table_add_col(table, heap, "ID", DATA_BINARY, 0, 8);
+	dict_mem_table_add_col(table, heap, "NAME", DATA_BINARY, 0, 0);
+	dict_mem_table_add_col(table, heap, "N_FIELDS", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "TYPE", DATA_INT, 0, 4);
+	/* SYS_INDEXES.SPACE is only read by in dict_drop_index_tree() */
+	dict_mem_table_add_col(table, heap, "SPACE", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "PAGE_NO", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "MERGE_THRESHOLD", DATA_INT, 0, 4);
+
+	table->id = DICT_INDEXES_ID;
+
+	dict_table_add_system_columns(table, heap);
+	/* The column SYS_INDEXES.MERGE_THRESHOLD was "instantly"
+	added in MySQL 5.7 and MariaDB 10.2.2. Assign it DEFAULT NULL.
+	Because of file format compatibility, we must treat SYS_INDEXES
+	as a special case, relaxing some debug assertions
+	for DICT_INDEXES_ID. */
+	dict_table_get_nth_col(table, DICT_COL__SYS_INDEXES__MERGE_THRESHOLD)
+		->def_val.len = UNIV_SQL_NULL;
+	table->add_to_cache();
+	dict_sys.sys_indexes = table;
+	mem_heap_empty(heap);
+
+	index = dict_mem_index_create(table, "CLUST_IND",
+				      DICT_UNIQUE | DICT_CLUSTERED, 2);
+
+	dict_mem_index_add_field(index, "TABLE_ID", 0);
+	dict_mem_index_add_field(index, "ID", 0);
+
+	index->id = DICT_INDEXES_ID;
+	err = dict_index_add_to_cache(
+		index, mach_read_from_4(dict_hdr + DICT_HDR_INDEXES));
+	ut_a(err == DB_SUCCESS);
+	ut_ad(!table->is_instant());
+	table->indexes.start->n_core_null_bytes = static_cast<uint8_t>(
+		UT_BITS_IN_BYTES(unsigned(table->indexes.start->n_nullable)));
+
+	/*-------------------------*/
+	table = dict_table_t::create(dict_sys.SYS_TABLE[dict_sys.SYS_FIELDS],
+				     fil_system.sys_space,
+				     DICT_NUM_COLS__SYS_FIELDS, 0, 0, 0);
+	dict_mem_table_add_col(table, heap, "INDEX_ID", DATA_BINARY, 0, 8);
+	dict_mem_table_add_col(table, heap, "POS", DATA_INT, 0, 4);
+	dict_mem_table_add_col(table, heap, "COL_NAME", DATA_BINARY, 0, 0);
+
+	table->id = DICT_FIELDS_ID;
+
+	dict_table_add_system_columns(table, heap);
+	table->add_to_cache();
+	dict_sys.sys_fields = table;
+	mem_heap_free(heap);
+
+	index = dict_mem_index_create(table, "CLUST_IND",
+				      DICT_UNIQUE | DICT_CLUSTERED, 2);
+
+	dict_mem_index_add_field(index, "INDEX_ID", 0);
+	dict_mem_index_add_field(index, "POS", 0);
+
+	index->id = DICT_FIELDS_ID;
+	err = dict_index_add_to_cache(
+		index, mach_read_from_4(dict_hdr + DICT_HDR_FIELDS));
+	ut_a(err == DB_SUCCESS);
+	ut_ad(!table->is_instant());
+	table->indexes.start->n_core_null_bytes = static_cast<uint8_t>(
+		UT_BITS_IN_BYTES(unsigned(table->indexes.start->n_nullable)));
+
+	mtr.commit();
+
+	err = ibuf_init_at_db_start();
+
+	if (err == DB_SUCCESS || srv_force_recovery >= SRV_FORCE_NO_DDL_UNDO) {
+		err = DB_SUCCESS;
+		/* Load definitions of other indexes on system tables */
+
+		dict_load_sys_table(dict_sys.sys_tables);
+		dict_load_sys_table(dict_sys.sys_columns);
+		dict_load_sys_table(dict_sys.sys_indexes);
+		dict_load_sys_table(dict_sys.sys_fields);
+		dict_sys.unlock();
+		dict_sys.load_sys_tables();
+	} else {
+		dict_sys.unlock();
+	}
+
+	return err;
+}
diff --git a/storage/innobase/dict/dict0crea.cc b/storage/innobase/dict/dict0crea.cc
new file mode 100644
index 00000000..cce5f2f2
--- /dev/null
+++ b/storage/innobase/dict/dict0crea.cc
@@ -0,0 +1,1906 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, 2023, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file dict/dict0crea.cc
+Database object creation
+
+Created 1/8/1996 Heikki Tuuri
+*******************************************************/
+
+#include "dict0crea.h"
+#include "btr0pcur.h"
+#ifdef BTR_CUR_HASH_ADAPT
+# include "btr0sea.h"
+#endif /* BTR_CUR_HASH_ADAPT */
+#include "page0page.h"
+#include "mach0data.h"
+#include "dict0boot.h"
+#include "dict0dict.h"
+#include "lock0lock.h"
+#include "que0que.h"
+#include "row0ins.h"
+#include "row0mysql.h"
+#include "pars0pars.h"
+#include "trx0roll.h"
+#include "trx0rseg.h"
+#include "trx0undo.h"
+#include "ut0vec.h"
+#include "fts0priv.h"
+#include "srv0start.h"
+#include "log.h"
+
+/*****************************************************************//**
+Based on a table object, this function builds the entry to be inserted
+in the SYS_TABLES system table.
+@return the tuple which should be inserted */
+static
+dtuple_t*
+dict_create_sys_tables_tuple(
+/*=========================*/
+	const dict_table_t*	table,	/*!< in: table */
+	mem_heap_t*		heap)	/*!< in: memory heap from
+					which the memory for the built
+					tuple is allocated */
+{
+	dtuple_t*	entry;
+	dfield_t*	dfield;
+	byte*		ptr;
+	ulint		type;
+
+	ut_ad(table);
+	ut_ad(!table->space || table->space->id == table->space_id);
+	ut_ad(heap);
+	ut_ad(table->n_cols >= DATA_N_SYS_COLS);
+
+	entry = dtuple_create(heap, 8 + DATA_N_SYS_COLS);
+
+	dict_table_copy_types(entry, dict_sys.sys_tables);
+
+	/* 0: NAME -----------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__NAME);
+
+	dfield_set_data(dfield,
+			table->name.m_name, strlen(table->name.m_name));
+
+	/* 1: DB_TRX_ID added later */
+	/* 2: DB_ROLL_PTR added later */
+	/* 3: ID -------------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__ID);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(ptr, table->id);
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 4: N_COLS ---------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__N_COLS);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+
+	/* If there is any virtual column, encode it in N_COLS */
+	mach_write_to_4(ptr, dict_table_encode_n_col(
+				ulint(table->n_cols - DATA_N_SYS_COLS),
+				ulint(table->n_v_def))
+			| (ulint(table->flags & DICT_TF_COMPACT) << 31));
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 5: TYPE (table flags) -----------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__TYPE);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+
+	/* Validate the table flags and convert them to what is saved in
+	SYS_TABLES.TYPE.  Table flag values 0 and 1 are both written to
+	SYS_TABLES.TYPE as 1. */
+	type = dict_tf_to_sys_tables_type(table->flags);
+	mach_write_to_4(ptr, type);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 6: MIX_ID (obsolete) ---------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__MIX_ID);
+
+	ptr = static_cast<byte*>(mem_heap_zalloc(heap, 8));
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 7: MIX_LEN (additional flags) --------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__MIX_LEN);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	/* Be sure all non-used bits are zero. */
+	ut_a(!(table->flags2 & DICT_TF2_UNUSED_BIT_MASK));
+	mach_write_to_4(ptr, table->flags2);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 8: CLUSTER_NAME ---------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__CLUSTER_ID);
+	dfield_set_null(dfield); /* not supported */
+
+	/* 9: SPACE ----------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_TABLES__SPACE);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, table->space_id);
+
+	dfield_set_data(dfield, ptr, 4);
+	/*----------------------------------*/
+
+	return(entry);
+}
+
+/*****************************************************************//**
+Based on a table object, this function builds the entry to be inserted
+in the SYS_COLUMNS system table.
+@return the tuple which should be inserted */
+static
+dtuple_t*
+dict_create_sys_columns_tuple(
+/*==========================*/
+	const dict_table_t*	table,	/*!< in: table */
+	ulint			i,	/*!< in: column number */
+	mem_heap_t*		heap)	/*!< in: memory heap from
+					which the memory for the built
+					tuple is allocated */
+{
+	dtuple_t*		entry;
+	const dict_col_t*	column;
+	dfield_t*		dfield;
+	byte*			ptr;
+	const char*		col_name;
+	ulint			num_base = 0;
+	ulint			v_col_no = ULINT_UNDEFINED;
+
+	ut_ad(table);
+	ut_ad(heap);
+
+	/* Any column beyond table->n_def would be virtual columns */
+        if (i >= table->n_def) {
+		dict_v_col_t*	v_col = dict_table_get_nth_v_col(
+					table, i - table->n_def);
+		column = &v_col->m_col;
+		num_base = v_col->num_base;
+		v_col_no = column->ind;
+	} else {
+		column = dict_table_get_nth_col(table, i);
+		ut_ad(!column->is_virtual());
+	}
+
+	entry = dtuple_create(heap, 7 + DATA_N_SYS_COLS);
+
+	dict_table_copy_types(entry, dict_sys.sys_columns);
+
+	/* 0: TABLE_ID -----------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__TABLE_ID);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(ptr, table->id);
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 1: POS ----------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__POS);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+
+	if (v_col_no != ULINT_UNDEFINED) {
+		/* encode virtual column's position in MySQL table and InnoDB
+		table in "POS" */
+		mach_write_to_4(ptr, dict_create_v_col_pos(
+				i - table->n_def, v_col_no));
+	} else {
+		mach_write_to_4(ptr, i);
+	}
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 2: DB_TRX_ID added later */
+	/* 3: DB_ROLL_PTR added later */
+	/* 4: NAME ---------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__NAME);
+
+        if (i >= table->n_def) {
+		col_name = dict_table_get_v_col_name(table, i - table->n_def);
+	} else {
+		col_name = dict_table_get_col_name(table, i);
+	}
+
+	dfield_set_data(dfield, col_name, strlen(col_name));
+
+	/* 5: MTYPE --------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__MTYPE);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, column->mtype);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 6: PRTYPE -------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__PRTYPE);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, column->prtype);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 7: LEN ----------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__LEN);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, column->len);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 8: PREC ---------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_COLUMNS__PREC);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, num_base);
+
+	dfield_set_data(dfield, ptr, 4);
+	/*---------------------------------*/
+
+	return(entry);
+}
+
+/** Based on a table object, this function builds the entry to be inserted
+in the SYS_VIRTUAL system table. Each row maps a virtual column to one of
+its base column.
+@param[in]	table	table
+@param[in]	v_col_n	virtual column number
+@param[in]	b_col_n	base column sequence num
+@param[in]	heap	memory heap
+@return the tuple which should be inserted */
+static
+dtuple_t*
+dict_create_sys_virtual_tuple(
+	const dict_table_t*	table,
+	ulint			v_col_n,
+	ulint			b_col_n,
+	mem_heap_t*		heap)
+{
+	dtuple_t*		entry;
+	const dict_col_t*	base_column;
+	dfield_t*		dfield;
+	byte*			ptr;
+
+	ut_ad(table);
+	ut_ad(heap);
+
+	ut_ad(v_col_n < table->n_v_def);
+	dict_v_col_t*	v_col = dict_table_get_nth_v_col(table, v_col_n);
+	base_column = v_col->base_col[b_col_n];
+
+	entry = dtuple_create(heap, DICT_NUM_COLS__SYS_VIRTUAL
+			      + DATA_N_SYS_COLS);
+
+	dict_table_copy_types(entry, dict_sys.sys_virtual);
+
+	/* 0: TABLE_ID -----------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_VIRTUAL__TABLE_ID);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(ptr, table->id);
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 1: POS ---------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_VIRTUAL__POS);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	ulint	v_col_no = dict_create_v_col_pos(v_col_n, v_col->m_col.ind);
+	mach_write_to_4(ptr, v_col_no);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 2: BASE_POS ----------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_VIRTUAL__BASE_POS);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, base_column->ind);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 3: DB_TRX_ID added later */
+	/* 4: DB_ROLL_PTR added later */
+
+	/*---------------------------------*/
+	return(entry);
+}
+
+/***************************************************************//**
+Builds a table definition to insert.
+@return DB_SUCCESS or error code */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dberr_t
+dict_build_table_def_step(
+/*======================*/
+	que_thr_t*	thr,	/*!< in: query thread */
+	tab_node_t*	node)	/*!< in: table create node */
+{
+	ut_ad(dict_sys.locked());
+	dict_table_t*	table = node->table;
+	ut_ad(!table->is_temporary());
+	ut_ad(!table->space);
+	ut_ad(table->space_id == UINT32_MAX);
+	dict_hdr_get_new_id(&table->id, nullptr, nullptr);
+
+	/* Always set this bit for all new created tables */
+	DICT_TF2_FLAG_SET(table, DICT_TF2_FTS_AUX_HEX_NAME);
+	DBUG_EXECUTE_IF("innodb_test_wrong_fts_aux_table_name",
+			DICT_TF2_FLAG_UNSET(table,
+					    DICT_TF2_FTS_AUX_HEX_NAME););
+
+	if (DICT_TF2_FLAG_IS_SET(table, DICT_TF2_USE_FILE_PER_TABLE)) {
+		/* This table will need a new tablespace. */
+
+		ut_ad(DICT_TF_GET_ZIP_SSIZE(table->flags) == 0
+		      || dict_table_has_atomic_blobs(table));
+		/* Get a new tablespace ID */
+		dict_hdr_get_new_id(NULL, NULL, &table->space_id);
+
+		DBUG_EXECUTE_IF(
+			"ib_create_table_fail_out_of_space_ids",
+			table->space_id = UINT32_MAX;
+		);
+
+		if (table->space_id == UINT32_MAX) {
+			return DB_ERROR;
+		}
+	} else {
+		ut_ad(dict_tf_get_rec_format(table->flags)
+		      != REC_FORMAT_COMPRESSED);
+		table->space = fil_system.sys_space;
+		table->space_id = TRX_SYS_SPACE;
+	}
+
+	ins_node_set_new_row(node->tab_def,
+			     dict_create_sys_tables_tuple(table, node->heap));
+	return DB_SUCCESS;
+}
+
+/** Builds a SYS_VIRTUAL row definition to insert.
+@param[in]	node	table create node */
+static
+void
+dict_build_v_col_def_step(
+	tab_node_t*	node)
+{
+	dtuple_t*	row;
+
+	row = dict_create_sys_virtual_tuple(node->table, node->col_no,
+					    node->base_col_no,
+					    node->heap);
+	ins_node_set_new_row(node->v_col_def, row);
+}
+
+/*****************************************************************//**
+Based on an index object, this function builds the entry to be inserted
+in the SYS_INDEXES system table.
+@return the tuple which should be inserted */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dtuple_t*
+dict_create_sys_indexes_tuple(
+/*==========================*/
+	const dict_index_t*	index,	/*!< in: index */
+	mem_heap_t*		heap)	/*!< in: memory heap from
+					which the memory for the built
+					tuple is allocated */
+{
+	dtuple_t*	entry;
+	dfield_t*	dfield;
+	byte*		ptr;
+
+	ut_ad(dict_sys.locked());
+	ut_ad(index);
+	ut_ad(index->table->space || !UT_LIST_GET_LEN(index->table->indexes)
+	      || index->table->file_unreadable);
+	ut_ad(!index->table->space
+	      || index->table->space->id == index->table->space_id);
+	ut_ad(heap);
+
+	entry = dtuple_create(
+		heap, DICT_NUM_COLS__SYS_INDEXES + DATA_N_SYS_COLS);
+
+	dict_table_copy_types(entry, dict_sys.sys_indexes);
+
+	/* 0: TABLE_ID -----------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__TABLE_ID);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(ptr, index->table->id);
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 1: ID ----------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__ID);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(ptr, index->id);
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 2: DB_TRX_ID added later */
+	/* 3: DB_ROLL_PTR added later */
+	/* 4: NAME --------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__NAME);
+
+	if (!index->is_committed()) {
+		ulint	len	= strlen(index->name) + 1;
+		char*	name	= static_cast<char*>(
+			mem_heap_alloc(heap, len));
+		*name = *TEMP_INDEX_PREFIX_STR;
+		memcpy(name + 1, index->name, len - 1);
+		dfield_set_data(dfield, name, len);
+	} else {
+		dfield_set_data(dfield, index->name, strlen(index->name));
+	}
+
+	/* 5: N_FIELDS ----------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__N_FIELDS);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, index->n_fields);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 6: TYPE --------------------------*/
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__TYPE);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, index->type);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 7: SPACE --------------------------*/
+
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__SPACE);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, index->table->space_id);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 8: PAGE_NO --------------------------*/
+
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__PAGE_NO);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, FIL_NULL);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 9: MERGE_THRESHOLD ----------------*/
+
+	dfield = dtuple_get_nth_field(
+		entry, DICT_COL__SYS_INDEXES__MERGE_THRESHOLD);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+	mach_write_to_4(ptr, DICT_INDEX_MERGE_THRESHOLD_DEFAULT);
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/*--------------------------------*/
+
+	return(entry);
+}
+
+/*****************************************************************//**
+Based on an index object, this function builds the entry to be inserted
+in the SYS_FIELDS system table.
+@return the tuple which should be inserted */
+static
+dtuple_t*
+dict_create_sys_fields_tuple(
+/*=========================*/
+	const dict_index_t*	index,	/*!< in: index */
+	ulint			fld_no,	/*!< in: field number */
+	mem_heap_t*		heap)	/*!< in: memory heap from
+					which the memory for the built
+					tuple is allocated */
+{
+	dtuple_t*	entry;
+	dict_field_t*	field;
+	dfield_t*	dfield;
+	byte*		ptr;
+	bool		wide_pos = false;
+
+	ut_ad(index);
+	ut_ad(heap);
+
+	for (unsigned j = 0; j < index->n_fields; j++) {
+		const dict_field_t* f = dict_index_get_nth_field(index, j);
+		if (f->prefix_len || f->descending) {
+			wide_pos = true;
+			break;
+		}
+	}
+
+	field = dict_index_get_nth_field(index, fld_no);
+
+	entry = dtuple_create(heap, 3 + DATA_N_SYS_COLS);
+
+	dict_table_copy_types(entry, dict_sys.sys_fields);
+
+	/* 0: INDEX_ID -----------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_FIELDS__INDEX_ID);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(ptr, index->id);
+
+	dfield_set_data(dfield, ptr, 8);
+
+	/* 1: POS; FIELD NUMBER & PREFIX LENGTH -----------------------*/
+
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_FIELDS__POS);
+
+	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
+
+	if (wide_pos) {
+		/* If there are column prefixes or columns with
+		descending order in the index, then we write the
+		field number to the 16 most significant bits,
+		the DESC flag to bit 15, and the prefix length
+		in the 15 least significant bits. */
+		mach_write_to_4(ptr, (fld_no << 16)
+				| (!!field->descending) << 15
+				| field->prefix_len);
+	} else {
+		/* Else we store the number of the field to the 2 LOW bytes.
+		This is to keep the storage format compatible with
+		InnoDB versions < 4.0.14. */
+
+		mach_write_to_4(ptr, fld_no);
+	}
+
+	dfield_set_data(dfield, ptr, 4);
+
+	/* 2: DB_TRX_ID added later */
+	/* 3: DB_ROLL_PTR added later */
+	/* 4: COL_NAME -------------------------*/
+	dfield = dtuple_get_nth_field(entry, DICT_COL__SYS_FIELDS__COL_NAME);
+
+	dfield_set_data(dfield, field->name, strlen(field->name));
+	/*---------------------------------*/
+
+	return(entry);
+}
+
+/*****************************************************************//**
+Creates the tuple with which the index entry is searched for writing the index
+tree root page number, if such a tree is created.
+@return the tuple for search */
+static
+dtuple_t*
+dict_create_search_tuple(
+/*=====================*/
+	const dtuple_t*	tuple,	/*!< in: the tuple inserted in the SYS_INDEXES
+				table */
+	mem_heap_t*	heap)	/*!< in: memory heap from which the memory for
+				the built tuple is allocated */
+{
+	dtuple_t*	search_tuple;
+	const dfield_t*	field1;
+	dfield_t*	field2;
+
+	ut_ad(tuple && heap);
+
+	search_tuple = dtuple_create(heap, 2);
+
+	field1 = dtuple_get_nth_field(tuple, 0);
+	field2 = dtuple_get_nth_field(search_tuple, 0);
+
+	dfield_copy(field2, field1);
+
+	field1 = dtuple_get_nth_field(tuple, 1);
+	field2 = dtuple_get_nth_field(search_tuple, 1);
+
+	dfield_copy(field2, field1);
+
+	ut_ad(dtuple_validate(search_tuple));
+
+	return(search_tuple);
+}
+
+/***************************************************************//**
+Builds an index definition row to insert.
+@return DB_SUCCESS or error code */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dberr_t
+dict_build_index_def_step(
+/*======================*/
+	que_thr_t*	thr,	/*!< in: query thread */
+	ind_node_t*	node)	/*!< in: index create node */
+{
+	dict_table_t*	table;
+	dict_index_t*	index;
+	dtuple_t*	row;
+	trx_t*		trx;
+
+	ut_ad(dict_sys.locked());
+
+	trx = thr_get_trx(thr);
+
+	index = node->index;
+
+	table = dict_table_open_on_name(
+		node->table_name, true, DICT_ERR_IGNORE_TABLESPACE);
+
+	if (!table) {
+		return DB_TABLE_NOT_FOUND;
+	}
+
+	index->table = table;
+
+	ut_ad((UT_LIST_GET_LEN(table->indexes) > 0)
+	      || dict_index_is_clust(index));
+
+	dict_hdr_get_new_id(NULL, &index->id, NULL);
+
+	node->page_no = FIL_NULL;
+	row = dict_create_sys_indexes_tuple(index, node->heap);
+	node->ind_row = row;
+
+	ins_node_set_new_row(node->ind_def, row);
+
+	/* Note that the index was created by this transaction. */
+	index->trx_id = trx->id;
+	ut_ad(table->def_trx_id <= trx->id);
+	table->def_trx_id = trx->id;
+	table->release();
+
+	return(DB_SUCCESS);
+}
+
+/***************************************************************//**
+Builds an index definition without updating SYSTEM TABLES.
+@return DB_SUCCESS or error code */
+void
+dict_build_index_def(
+/*=================*/
+	const dict_table_t*	table,	/*!< in: table */
+	dict_index_t*		index,	/*!< in/out: index */
+	trx_t*			trx)	/*!< in/out: InnoDB transaction handle */
+{
+	ut_ad(dict_sys.locked());
+
+	ut_ad((UT_LIST_GET_LEN(table->indexes) > 0)
+	      || dict_index_is_clust(index));
+
+	dict_hdr_get_new_id(NULL, &index->id, NULL);
+
+	/* Note that the index was created by this transaction. */
+	index->trx_id = trx->id;
+}
+
+/***************************************************************//**
+Builds a field definition row to insert. */
+static
+void
+dict_build_field_def_step(
+/*======================*/
+	ind_node_t*	node)	/*!< in: index create node */
+{
+	dict_index_t*	index;
+	dtuple_t*	row;
+
+	index = node->index;
+
+	row = dict_create_sys_fields_tuple(index, node->field_no, node->heap);
+
+	ins_node_set_new_row(node->field_def, row);
+}
+
+/***************************************************************//**
+Creates an index tree for the index.
+@return DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dberr_t
+dict_create_index_tree_step(
+/*========================*/
+	ind_node_t*	node)	/*!< in: index create node */
+{
+	mtr_t		mtr;
+	btr_pcur_t	pcur;
+	dict_index_t*	index;
+	dtuple_t*	search_tuple;
+
+	ut_ad(dict_sys.locked());
+
+	index = node->index;
+
+	if (index->type == DICT_FTS) {
+		/* FTS index does not need an index tree */
+		return(DB_SUCCESS);
+	}
+
+	/* Run a mini-transaction in which the index tree is allocated for
+	the index and its root address is written to the index entry in
+	sys_indexes */
+
+	mtr.start();
+
+	search_tuple = dict_create_search_tuple(node->ind_row, node->heap);
+	node->page_no = FIL_NULL;
+	pcur.btr_cur.page_cur.index =
+		UT_LIST_GET_FIRST(dict_sys.sys_indexes->indexes);
+
+	dberr_t err = btr_pcur_open(search_tuple, PAGE_CUR_L, BTR_MODIFY_LEAF,
+				    &pcur, &mtr);
+
+	if (err != DB_SUCCESS) {
+func_exit:
+		mtr.commit();
+		return err;
+	}
+
+	btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+
+	if (UNIV_UNLIKELY(btr_pcur_is_after_last_on_page(&pcur))) {
+corrupted:
+		err = DB_CORRUPTION;
+		goto func_exit;
+	}
+
+	ulint	len;
+	byte*	data = rec_get_nth_field_old(btr_pcur_get_rec(&pcur),
+					     DICT_FLD__SYS_INDEXES__ID,
+					     &len);
+	if (UNIV_UNLIKELY(len != 8 || mach_read_from_8(data) != index->id)) {
+		goto corrupted;
+	}
+
+	data = rec_get_nth_field_old(btr_pcur_get_rec(&pcur),
+				     DICT_FLD__SYS_INDEXES__PAGE_NO, &len);
+	if (len != 4) {
+		goto corrupted;
+	}
+
+	if (index->is_readable()) {
+		index->set_modified(mtr);
+
+		node->page_no = btr_create(
+			index->type, index->table->space,
+			index->id, index, &mtr, &err);
+
+		DBUG_EXECUTE_IF("ib_import_create_index_failure_1",
+				node->page_no = FIL_NULL;
+				err = DB_OUT_OF_FILE_SPACE; );
+	}
+
+	mtr.write<4,mtr_t::MAYBE_NOP>(*btr_pcur_get_block(&pcur), data,
+				      node->page_no);
+	goto func_exit;
+}
+
+/***************************************************************//**
+Creates an index tree for the index if it is not a member of a cluster.
+Don't update SYSTEM TABLES.
+@return error code */
+dberr_t
+dict_create_index_tree_in_mem(
+/*==========================*/
+	dict_index_t*	index,	/*!< in/out: index */
+	const trx_t*	trx)	/*!< in: InnoDB transaction handle */
+{
+	mtr_t		mtr;
+
+	ut_ad(dict_sys.locked());
+	ut_ad(!(index->type & DICT_FTS));
+
+	mtr_start(&mtr);
+	mtr_set_log_mode(&mtr, MTR_LOG_NO_REDO);
+
+	/* Currently this function is being used by temp-tables only.
+	Import/Discard of temp-table is blocked and so this assert. */
+	ut_ad(index->is_readable());
+	ut_ad(!(index->table->flags2 & DICT_TF2_DISCARDED));
+
+	dberr_t err;
+	index->page = btr_create(index->type, index->table->space,
+				 index->id, index, &mtr, &err);
+	mtr_commit(&mtr);
+
+	index->trx_id = trx->id;
+
+	return err;
+}
+
+/** Drop the index tree associated with a row in SYS_INDEXES table.
+@param[in,out]	pcur	persistent cursor on rec
+@param[in,out]	trx	dictionary transaction
+@param[in,out]	mtr	mini-transaction
+@return tablespace ID to drop (if this is the clustered index)
+@retval 0 if no tablespace is to be dropped */
+uint32_t dict_drop_index_tree(btr_pcur_t *pcur, trx_t *trx, mtr_t *mtr)
+{
+  rec_t *rec= btr_pcur_get_rec(pcur);
+
+  ut_ad(!trx || dict_sys.locked());
+  ut_ad(!dict_table_is_comp(dict_sys.sys_indexes));
+  btr_pcur_store_position(pcur, mtr);
+
+  static_assert(DICT_FLD__SYS_INDEXES__TABLE_ID == 0, "compatibility");
+  static_assert(DICT_FLD__SYS_INDEXES__ID == 1, "compatibility");
+
+  ulint len= rec_get_n_fields_old(rec);
+  if (len < DICT_FLD__SYS_INDEXES__MERGE_THRESHOLD ||
+      len > DICT_NUM_FIELDS__SYS_INDEXES)
+  {
+rec_corrupted:
+    sql_print_error("InnoDB: Corrupted SYS_INDEXES record");
+    return 0;
+  }
+
+  if (rec_get_1byte_offs_flag(rec))
+  {
+    if (rec_1_get_field_end_info(rec, 0) != 8 ||
+        rec_1_get_field_end_info(rec, 1) != 8 + 8)
+      goto rec_corrupted;
+  }
+  else if (rec_2_get_field_end_info(rec, 0) != 8 ||
+           rec_2_get_field_end_info(rec, 1) != 8 + 8)
+    goto rec_corrupted;
+
+  const byte *p= rec_get_nth_field_old(rec, DICT_FLD__SYS_INDEXES__TYPE, &len);
+  if (len != 4)
+    goto rec_corrupted;
+  const uint32_t type= mach_read_from_4(p);
+  p= rec_get_nth_field_old(rec, DICT_FLD__SYS_INDEXES__PAGE_NO, &len);
+  if (len != 4)
+    goto rec_corrupted;
+  const uint32_t root_page_no= mach_read_from_4(p);
+  p= rec_get_nth_field_old(rec, DICT_FLD__SYS_INDEXES__SPACE, &len);
+  if (len != 4)
+    goto rec_corrupted;
+
+  const uint32_t space_id= mach_read_from_4(p);
+  ut_ad(root_page_no == FIL_NULL || space_id <= SRV_SPACE_ID_UPPER_BOUND);
+
+  if (space_id && (type & DICT_CLUSTERED))
+    return space_id;
+
+  if (root_page_no == FIL_NULL)
+    /* The tree has already been freed */;
+  else if (fil_space_t*s= fil_space_t::get(space_id))
+  {
+    /* Ensure that the tablespace file exists
+    in order to avoid a crash in buf_page_get_gen(). */
+    if (root_page_no < s->get_size())
+    {
+      static_assert(FIL_NULL == 0xffffffff, "compatibility");
+      static_assert(DICT_FLD__SYS_INDEXES__PAGE_NO ==
+                    DICT_FLD__SYS_INDEXES__SPACE + 1, "compatibility");
+      mtr->memset(btr_pcur_get_block(pcur), page_offset(p + 4), 4, 0xff);
+      btr_free_if_exists(s, root_page_no, mach_read_from_8(rec + 8), mtr);
+    }
+    s->release();
+  }
+
+  return 0;
+}
+
+/*********************************************************************//**
+Creates a table create graph.
+@return own: table create node */
+tab_node_t*
+tab_create_graph_create(
+/*====================*/
+	dict_table_t*	table,	/*!< in: table to create, built as a memory data
+				structure */
+	mem_heap_t*	heap)	/*!< in: heap where created */
+{
+	tab_node_t*	node;
+
+	node = static_cast<tab_node_t*>(
+		mem_heap_alloc(heap, sizeof(tab_node_t)));
+
+	node->common.type = QUE_NODE_CREATE_TABLE;
+
+	node->table = table;
+
+	node->state = TABLE_BUILD_TABLE_DEF;
+	node->heap = mem_heap_create(256);
+
+	node->tab_def = ins_node_create(INS_DIRECT, dict_sys.sys_tables,
+					heap);
+	node->tab_def->common.parent = node;
+
+	node->col_def = ins_node_create(INS_DIRECT, dict_sys.sys_columns,
+					heap);
+	node->col_def->common.parent = node;
+
+	node->v_col_def = ins_node_create(INS_DIRECT, dict_sys.sys_virtual,
+                                          heap);
+	node->v_col_def->common.parent = node;
+
+	return(node);
+}
+
+/** Creates an index create graph.
+@param[in]	index	index to create, built as a memory data structure
+@param[in]	table	table name
+@param[in,out]	heap	heap where created
+@param[in]	mode	encryption mode (for creating a table)
+@param[in]	key_id	encryption key identifier (for creating a table)
+@param[in]	add_v	new virtual columns added in the same clause with
+			add index
+@return own: index create node */
+ind_node_t*
+ind_create_graph_create(
+	dict_index_t*		index,
+	const char*		table,
+	mem_heap_t*		heap,
+	fil_encryption_t	mode,
+	uint32_t		key_id,
+	const dict_add_v_col_t*	add_v)
+{
+	ind_node_t*	node;
+
+	node = static_cast<ind_node_t*>(
+		mem_heap_alloc(heap, sizeof(ind_node_t)));
+
+	node->common.type = QUE_NODE_CREATE_INDEX;
+
+	node->index = index;
+
+	node->table_name = table;
+
+	node->key_id = key_id;
+	node->mode = mode;
+	node->add_v = add_v;
+
+	node->state = INDEX_BUILD_INDEX_DEF;
+	node->page_no = FIL_NULL;
+	node->heap = mem_heap_create(256);
+
+	node->ind_def = ins_node_create(INS_DIRECT,
+					dict_sys.sys_indexes, heap);
+	node->ind_def->common.parent = node;
+
+	node->field_def = ins_node_create(INS_DIRECT,
+					  dict_sys.sys_fields, heap);
+	node->field_def->common.parent = node;
+
+	return(node);
+}
+
+/***********************************************************//**
+Creates a table. This is a high-level function used in SQL execution graphs.
+@return query thread to run next or NULL */
+que_thr_t*
+dict_create_table_step(
+/*===================*/
+	que_thr_t*	thr)	/*!< in: query thread */
+{
+	tab_node_t*	node;
+	dberr_t		err	= DB_ERROR;
+	trx_t*		trx;
+
+	ut_ad(thr);
+	ut_ad(dict_sys.locked());
+
+	trx = thr_get_trx(thr);
+
+	node = static_cast<tab_node_t*>(thr->run_node);
+
+	ut_ad(que_node_get_type(node) == QUE_NODE_CREATE_TABLE);
+
+	if (thr->prev_node == que_node_get_parent(node)) {
+		node->state = TABLE_BUILD_TABLE_DEF;
+	}
+
+	if (node->state == TABLE_BUILD_TABLE_DEF) {
+
+		/* DO THE CHECKS OF THE CONSISTENCY CONSTRAINTS HERE */
+
+		err = dict_build_table_def_step(thr, node);
+		if (err != DB_SUCCESS) {
+
+			goto function_exit;
+		}
+
+		node->state = TABLE_BUILD_COL_DEF;
+		node->col_no = 0;
+
+		thr->run_node = node->tab_def;
+
+		return(thr);
+	}
+
+	if (node->state == TABLE_BUILD_COL_DEF) {
+		if (node->col_no + DATA_N_SYS_COLS
+		    < (static_cast<ulint>(node->table->n_def)
+		       + static_cast<ulint>(node->table->n_v_def))) {
+
+			ulint i = node->col_no++;
+			if (i + DATA_N_SYS_COLS >= node->table->n_def) {
+				i += DATA_N_SYS_COLS;
+			}
+
+			ins_node_set_new_row(
+				node->col_def,
+				dict_create_sys_columns_tuple(node->table, i,
+							      node->heap));
+
+			thr->run_node = node->col_def;
+
+			return(thr);
+		} else {
+			/* Move on to SYS_VIRTUAL table */
+			node->col_no = 0;
+                        node->base_col_no = 0;
+                        node->state = TABLE_BUILD_V_COL_DEF;
+		}
+	}
+
+	if (node->state == TABLE_BUILD_V_COL_DEF) {
+
+		if (node->col_no < static_cast<ulint>(node->table->n_v_def)) {
+			dict_v_col_t*   v_col = dict_table_get_nth_v_col(
+						node->table, node->col_no);
+
+			/* If no base column */
+			while (v_col->num_base == 0) {
+				node->col_no++;
+				if (node->col_no == static_cast<ulint>(
+					(node->table)->n_v_def)) {
+					node->state = TABLE_ADD_TO_CACHE;
+					break;
+				}
+
+				v_col = dict_table_get_nth_v_col(
+					node->table, node->col_no);
+				node->base_col_no = 0;
+			}
+
+			if (node->state != TABLE_ADD_TO_CACHE) {
+				ut_ad(node->col_no == v_col->v_pos);
+				dict_build_v_col_def_step(node);
+
+				if (node->base_col_no
+				    < unsigned{v_col->num_base} - 1) {
+					/* move on to next base column */
+					node->base_col_no++;
+				} else {
+					/* move on to next virtual column */
+					node->col_no++;
+					node->base_col_no = 0;
+				}
+
+				thr->run_node = node->v_col_def;
+
+				return(thr);
+			}
+		} else {
+			node->state = TABLE_ADD_TO_CACHE;
+		}
+	}
+
+	if (node->state == TABLE_ADD_TO_CACHE) {
+		node->table->can_be_evicted = !node->table->fts;
+		node->table->add_to_cache();
+
+		err = DB_SUCCESS;
+	}
+
+function_exit:
+	trx->error_state = err;
+
+	if (err != DB_SUCCESS) {
+		return(NULL);
+	}
+
+	thr->run_node = que_node_get_parent(node);
+
+	return(thr);
+}
+
+static dberr_t dict_create_index_space(const ind_node_t &node)
+{
+  dict_table_t *table= node.index->table;
+  if (table->space || (table->flags2 & DICT_TF2_DISCARDED))
+    return DB_SUCCESS;
+  ut_ad(table->space_id);
+  ut_ad(table->space_id < SRV_TMP_SPACE_ID);
+  /* Determine the tablespace flags. */
+  const bool has_data_dir= DICT_TF_HAS_DATA_DIR(table->flags);
+  ut_ad(!has_data_dir || table->data_dir_path);
+  char* filepath= fil_make_filepath(has_data_dir
+                                    ? table->data_dir_path : nullptr,
+                                    table->name, IBD, has_data_dir);
+  if (!filepath)
+    return DB_OUT_OF_MEMORY;
+
+  /* We create a new single-table tablespace for the table.
+  We initially let it be 4 pages:
+  - page 0 is the fsp header and an extent descriptor page,
+  - page 1 is an ibuf bitmap page,
+  - page 2 is the first inode page,
+  - page 3 will contain the root of the clustered index of
+  the table we create here. */
+  dberr_t err;
+  table->space= fil_ibd_create(table->space_id, table->name, filepath,
+                               dict_tf_to_fsp_flags(table->flags),
+                               FIL_IBD_FILE_INITIAL_SIZE,
+                               node.mode, node.key_id, &err);
+  ut_ad((err != DB_SUCCESS) == !table->space);
+  ut_free(filepath);
+
+  return err;
+}
+
+/***********************************************************//**
+Creates an index. This is a high-level function used in SQL execution
+graphs.
+@return query thread to run next or NULL */
+que_thr_t*
+dict_create_index_step(
+/*===================*/
+	que_thr_t*	thr)	/*!< in: query thread */
+{
+	ind_node_t*	node;
+	dberr_t		err	= DB_ERROR;
+	trx_t*		trx;
+
+	ut_ad(thr);
+	ut_ad(dict_sys.locked());
+
+	trx = thr_get_trx(thr);
+
+	node = static_cast<ind_node_t*>(thr->run_node);
+
+	ut_ad(que_node_get_type(node) == QUE_NODE_CREATE_INDEX);
+
+	if (thr->prev_node == que_node_get_parent(node)) {
+		node->state = INDEX_BUILD_INDEX_DEF;
+	}
+
+	if (node->state == INDEX_BUILD_INDEX_DEF) {
+		/* DO THE CHECKS OF THE CONSISTENCY CONSTRAINTS HERE */
+		err = dict_build_index_def_step(thr, node);
+
+		if (err != DB_SUCCESS) {
+
+			goto function_exit;
+		}
+
+		node->state = INDEX_BUILD_FIELD_DEF;
+		node->field_no = 0;
+
+		thr->run_node = node->ind_def;
+
+		return(thr);
+	}
+
+	if (node->state == INDEX_BUILD_FIELD_DEF) {
+		err = dict_create_index_space(*node);
+		if (err != DB_SUCCESS) {
+			dict_mem_index_free(node->index);
+			node->index = nullptr;
+			goto function_exit;
+		}
+
+		if (node->field_no < (node->index)->n_fields) {
+
+			dict_build_field_def_step(node);
+
+			node->field_no++;
+
+			thr->run_node = node->field_def;
+
+			return(thr);
+		} else {
+			node->state = INDEX_ADD_TO_CACHE;
+		}
+	}
+
+	if (node->state == INDEX_ADD_TO_CACHE) {
+		err = dict_index_add_to_cache(node->index, FIL_NULL,
+					      node->add_v);
+
+		ut_ad(!node->index == (err != DB_SUCCESS));
+
+		if (!node->index) {
+			goto function_exit;
+		}
+
+		ut_ad(!node->index->is_instant());
+		ut_ad(node->index->n_core_null_bytes
+		      == ((dict_index_is_clust(node->index)
+			   && node->index->table->supports_instant())
+			  ? dict_index_t::NO_CORE_NULL_BYTES
+			  : UT_BITS_IN_BYTES(
+				  unsigned(node->index->n_nullable))));
+		node->index->n_core_null_bytes = static_cast<uint8_t>(
+			UT_BITS_IN_BYTES(unsigned(node->index->n_nullable)));
+		node->state = INDEX_CREATE_INDEX_TREE;
+	}
+
+	if (node->state == INDEX_CREATE_INDEX_TREE) {
+
+		err = dict_create_index_tree_step(node);
+
+		DBUG_EXECUTE_IF("ib_dict_create_index_tree_fail",
+				err = DB_OUT_OF_MEMORY;);
+
+		if (err != DB_SUCCESS) {
+			dict_table_t* table = node->index->table;
+			/* If this is a FTS index, we will need to remove
+			it from fts->cache->indexes list as well */
+			if (!(node->index->type & DICT_FTS)) {
+			} else if (auto fts = table->fts) {
+				fts_index_cache_t*	index_cache;
+
+				mysql_mutex_lock(&fts->cache->init_lock);
+
+				index_cache = (fts_index_cache_t*)
+					 fts_find_index_cache(
+						fts->cache,
+						node->index);
+
+				if (index_cache->words) {
+					rbt_free(index_cache->words);
+					index_cache->words = 0;
+				}
+
+				ib_vector_remove(
+					fts->cache->indexes,
+					*reinterpret_cast<void**>(index_cache));
+
+				mysql_mutex_unlock(&fts->cache->init_lock);
+			}
+
+#ifdef BTR_CUR_HASH_ADAPT
+			ut_ad(!node->index->search_info->ref_count);
+#endif /* BTR_CUR_HASH_ADAPT */
+			dict_index_remove_from_cache(table, node->index);
+			node->index = NULL;
+
+			goto function_exit;
+		}
+
+		node->index->page = node->page_no;
+		/* These should have been set in
+		dict_build_index_def_step() and
+		dict_index_add_to_cache(). */
+		ut_ad(node->index->trx_id == trx->id);
+		ut_ad(node->index->table->def_trx_id == trx->id);
+	}
+
+function_exit:
+	trx->error_state = err;
+
+	if (UNIV_UNLIKELY(err != DB_SUCCESS)) {
+		return nullptr;
+	}
+
+	thr->run_node = que_node_get_parent(node);
+
+	return(thr);
+}
+
+bool dict_sys_t::load_sys_tables()
+{
+  ut_ad(!srv_any_background_activity());
+  bool mismatch= false;
+  lock(SRW_LOCK_CALL);
+  if (!(sys_foreign= load_table(SYS_TABLE[SYS_FOREIGN],
+                                DICT_ERR_IGNORE_FK_NOKEY)));
+  else if (UT_LIST_GET_LEN(sys_foreign->indexes) == 3 &&
+           sys_foreign->n_cols == DICT_NUM_COLS__SYS_FOREIGN + DATA_N_SYS_COLS)
+    prevent_eviction(sys_foreign);
+  else
+  {
+    sys_foreign= nullptr;
+    mismatch= true;
+    sql_print_error("InnoDB: Invalid definition of SYS_FOREIGN");
+  }
+  if (!(sys_foreign_cols= load_table(SYS_TABLE[SYS_FOREIGN_COLS],
+                                     DICT_ERR_IGNORE_FK_NOKEY)));
+  else if (UT_LIST_GET_LEN(sys_foreign_cols->indexes) == 1 &&
+           sys_foreign_cols->n_cols ==
+           DICT_NUM_COLS__SYS_FOREIGN_COLS + DATA_N_SYS_COLS)
+    prevent_eviction(sys_foreign_cols);
+  else
+  {
+    sys_foreign_cols= nullptr;
+    mismatch= true;
+    sql_print_error("InnoDB: Invalid definition of SYS_FOREIGN_COLS");
+  }
+  if (!(sys_virtual= load_table(SYS_TABLE[SYS_VIRTUAL],
+                                DICT_ERR_IGNORE_FK_NOKEY)));
+  else if (UT_LIST_GET_LEN(sys_virtual->indexes) == 1 &&
+           sys_virtual->n_cols == DICT_NUM_COLS__SYS_VIRTUAL + DATA_N_SYS_COLS)
+    prevent_eviction(sys_virtual);
+  else
+  {
+    sys_virtual= nullptr;
+    mismatch= true;
+    sql_print_error("InnoDB: Invalid definition of SYS_VIRTUAL");
+  }
+  unlock();
+  return mismatch;
+}
+
+dberr_t dict_sys_t::create_or_check_sys_tables()
+{
+  if (sys_tables_exist())
+    return DB_SUCCESS;
+
+  if (srv_read_only_mode || srv_force_recovery >= SRV_FORCE_NO_TRX_UNDO)
+    return DB_READ_ONLY;
+
+  if (load_sys_tables())
+  {
+    sql_print_information("InnoDB: Set innodb_read_only=1 "
+                          "or innodb_force_recovery=3 to start up");
+    return DB_CORRUPTION;
+  }
+
+  if (sys_tables_exist())
+    return DB_SUCCESS;
+
+  trx_t *trx= trx_create();
+  trx_start_for_ddl(trx);
+
+  {
+    /* Do not bother with transactional memory; this is only
+    executed at startup, with no conflicts present. */
+    LockMutexGuard g{SRW_LOCK_CALL};
+    trx->mutex_lock();
+    lock_table_create(dict_sys.sys_tables, LOCK_X, trx);
+    lock_table_create(dict_sys.sys_columns, LOCK_X, trx);
+    lock_table_create(dict_sys.sys_indexes, LOCK_X, trx);
+    lock_table_create(dict_sys.sys_fields, LOCK_X, trx);
+    trx->mutex_unlock();
+  }
+
+  row_mysql_lock_data_dictionary(trx);
+
+  /* NOTE: when designing InnoDB's foreign key support in 2001, Heikki Tuuri
+  made a mistake and defined table names and the foreign key id to be of type
+  CHAR (internally, really VARCHAR). The type should have been VARBINARY. */
+
+  /* System tables are always created inside the system tablespace. */
+  const auto srv_file_per_table_backup= srv_file_per_table;
+  srv_file_per_table= 0;
+  dberr_t error;
+  span<const char> tablename;
+
+  if (!sys_foreign)
+  {
+    error= que_eval_sql(nullptr, "PROCEDURE CREATE_FOREIGN() IS\n"
+                        "BEGIN\n"
+                        "CREATE TABLE\n"
+                        "SYS_FOREIGN(ID CHAR, FOR_NAME CHAR,"
+                        " REF_NAME CHAR, N_COLS INT);\n"
+                        "CREATE UNIQUE CLUSTERED INDEX ID_IND"
+                        " ON SYS_FOREIGN (ID);\n"
+                        "CREATE INDEX FOR_IND"
+                        " ON SYS_FOREIGN (FOR_NAME);\n"
+                        "CREATE INDEX REF_IND"
+                        " ON SYS_FOREIGN (REF_NAME);\n"
+                        "END;\n", trx);
+    if (UNIV_UNLIKELY(error != DB_SUCCESS))
+    {
+      tablename= SYS_TABLE[SYS_FOREIGN];
+err_exit:
+      sql_print_error("InnoDB: Creation of %.*s failed: %s",
+                      int(tablename.size()), tablename.data(),
+                      ut_strerr(error));
+      trx->rollback();
+      row_mysql_unlock_data_dictionary(trx);
+      trx->free();
+      srv_file_per_table= srv_file_per_table_backup;
+      return error;
+    }
+  }
+  if (!sys_foreign_cols)
+  {
+    error= que_eval_sql(nullptr, "PROCEDURE CREATE_FOREIGN_COLS() IS\n"
+                        "BEGIN\n"
+                        "CREATE TABLE\n"
+                        "SYS_FOREIGN_COLS(ID CHAR, POS INT,"
+                        " FOR_COL_NAME CHAR, REF_COL_NAME CHAR);\n"
+                        "CREATE UNIQUE CLUSTERED INDEX ID_IND"
+                        " ON SYS_FOREIGN_COLS (ID, POS);\n"
+                        "END;\n", trx);
+    if (UNIV_UNLIKELY(error != DB_SUCCESS))
+    {
+      tablename= SYS_TABLE[SYS_FOREIGN_COLS];
+      goto err_exit;
+    }
+  }
+  if (!sys_virtual)
+  {
+    error= que_eval_sql(nullptr, "PROCEDURE CREATE_VIRTUAL() IS\n"
+                        "BEGIN\n"
+                        "CREATE TABLE\n"
+                        "SYS_VIRTUAL(TABLE_ID BIGINT,POS INT,BASE_POS INT);\n"
+                        "CREATE UNIQUE CLUSTERED INDEX BASE_IDX"
+                        " ON SYS_VIRTUAL(TABLE_ID, POS, BASE_POS);\n"
+                        "END;\n", trx);
+    if (UNIV_UNLIKELY(error != DB_SUCCESS))
+    {
+      tablename= SYS_TABLE[SYS_VIRTUAL];
+      goto err_exit;
+    }
+  }
+
+  trx->commit();
+  row_mysql_unlock_data_dictionary(trx);
+  trx->free();
+  srv_file_per_table= srv_file_per_table_backup;
+
+  lock(SRW_LOCK_CALL);
+  if (sys_foreign);
+  else if (!(sys_foreign= load_table(SYS_TABLE[SYS_FOREIGN])))
+  {
+    tablename= SYS_TABLE[SYS_FOREIGN];
+load_fail:
+    unlock();
+    sql_print_error("InnoDB: Failed to CREATE TABLE %.*s",
+                    int(tablename.size()), tablename.data());
+    return DB_TABLE_NOT_FOUND;
+  }
+  else
+    prevent_eviction(sys_foreign);
+
+  if (sys_foreign_cols);
+  else if (!(sys_foreign_cols= load_table(SYS_TABLE[SYS_FOREIGN_COLS])))
+  {
+    tablename= SYS_TABLE[SYS_FOREIGN_COLS];
+    goto load_fail;
+  }
+  else
+    prevent_eviction(sys_foreign_cols);
+
+  if (sys_virtual);
+  else if (!(sys_virtual= load_table(SYS_TABLE[SYS_VIRTUAL])))
+  {
+    tablename= SYS_TABLE[SYS_VIRTUAL];
+    goto load_fail;
+  }
+  else
+    prevent_eviction(sys_virtual);
+
+  unlock();
+  return DB_SUCCESS;
+}
+
+/****************************************************************//**
+Evaluate the given foreign key SQL statement.
+@return error code or DB_SUCCESS */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dberr_t
+dict_foreign_eval_sql(
+/*==================*/
+	pars_info_t*	info,	/*!< in: info struct */
+	const char*	sql,	/*!< in: SQL string to evaluate */
+	const char*	name,	/*!< in: table name (for diagnostics) */
+	const char*	id,	/*!< in: foreign key id */
+	trx_t*		trx)	/*!< in/out: transaction */
+{
+	FILE*	ef	= dict_foreign_err_file;
+
+	dberr_t error = que_eval_sql(info, sql, trx);
+
+	switch (error) {
+	case DB_SUCCESS:
+		break;
+	case DB_DUPLICATE_KEY:
+		mysql_mutex_lock(&dict_foreign_err_mutex);
+		rewind(ef);
+		ut_print_timestamp(ef);
+		fputs(" Error in foreign key constraint creation for table ",
+		      ef);
+		ut_print_name(ef, trx, name);
+		fputs(".\nA foreign key constraint of name ", ef);
+		ut_print_name(ef, trx, id);
+		fputs("\nalready exists."
+		      " (Note that internally InnoDB adds 'databasename'\n"
+		      "in front of the user-defined constraint name.)\n"
+		      "Note that InnoDB's FOREIGN KEY system tables store\n"
+		      "constraint names as case-insensitive, with the\n"
+		      "MariaDB standard latin1_swedish_ci collation. If you\n"
+		      "create tables or databases whose names differ only in\n"
+		      "the character case, then collisions in constraint\n"
+		      "names can occur. Workaround: name your constraints\n"
+		      "explicitly with unique names.\n",
+		      ef);
+		goto release;
+	default:
+		sql_print_error("InnoDB: "
+				"Foreign key constraint creation failed: %s",
+				ut_strerr(error));
+
+		mysql_mutex_lock(&dict_foreign_err_mutex);
+		ut_print_timestamp(ef);
+		fputs(" Internal error in foreign key constraint creation"
+		      " for table ", ef);
+		ut_print_name(ef, trx, name);
+		fputs(".\n"
+		      "See the MariaDB .err log in the datadir"
+		      " for more information.\n", ef);
+release:
+		mysql_mutex_unlock(&dict_foreign_err_mutex);
+	}
+
+	return error;
+}
+
+/********************************************************************//**
+Add a single foreign key field definition to the data dictionary tables in
+the database.
+@return error code or DB_SUCCESS */
+static MY_ATTRIBUTE((nonnull, warn_unused_result))
+dberr_t
+dict_create_add_foreign_field_to_dictionary(
+/*========================================*/
+	ulint			field_nr,	/*!< in: field number */
+	const char*		table_name,	/*!< in: table name */
+	const dict_foreign_t*	foreign,	/*!< in: foreign */
+	trx_t*			trx)		/*!< in/out: transaction */
+{
+	DBUG_ENTER("dict_create_add_foreign_field_to_dictionary");
+
+	pars_info_t*	info = pars_info_create();
+
+	pars_info_add_str_literal(info, "id", foreign->id);
+
+	pars_info_add_int4_literal(info, "pos", field_nr);
+
+	pars_info_add_str_literal(info, "for_col_name",
+				  foreign->foreign_col_names[field_nr]);
+
+	pars_info_add_str_literal(info, "ref_col_name",
+				  foreign->referenced_col_names[field_nr]);
+
+	DBUG_RETURN(dict_foreign_eval_sql(
+		       info,
+		       "PROCEDURE P () IS\n"
+		       "BEGIN\n"
+		       "INSERT INTO SYS_FOREIGN_COLS VALUES"
+		       "(:id, :pos, :for_col_name, :ref_col_name);\n"
+		       "END;\n",
+		       table_name, foreign->id, trx));
+}
+
+/********************************************************************//**
+Construct foreign key constraint defintion from data dictionary information.
+*/
+static
+char*
+dict_foreign_def_get(
+/*=================*/
+	dict_foreign_t*	foreign,/*!< in: foreign */
+	trx_t*		trx)	/*!< in: trx */
+{
+	char* fk_def = (char *)mem_heap_alloc(foreign->heap, 4*1024);
+	const char* tbname;
+	char tablebuf[MAX_TABLE_NAME_LEN + 1] = "";
+	unsigned i;
+	char* bufend;
+
+	tbname = dict_remove_db_name(foreign->id);
+	bufend = innobase_convert_name(tablebuf, MAX_TABLE_NAME_LEN,
+				tbname, strlen(tbname), trx->mysql_thd);
+	tablebuf[bufend - tablebuf] = '\0';
+
+	sprintf(fk_def,
+		(char *)"CONSTRAINT %s FOREIGN KEY (", (char *)tablebuf);
+
+	for(i = 0; i < foreign->n_fields; i++) {
+		char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+		innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->foreign_col_names[i],
+				strlen(foreign->foreign_col_names[i]),
+				trx->mysql_thd);
+		strcat(fk_def, buf);
+		if (i < static_cast<unsigned>(foreign->n_fields-1)) {
+			strcat(fk_def, (char *)",");
+		}
+	}
+
+	strcat(fk_def,(char *)") REFERENCES ");
+
+	bufend = innobase_convert_name(tablebuf, MAX_TABLE_NAME_LEN,
+	        	        foreign->referenced_table_name,
+			        strlen(foreign->referenced_table_name),
+			        trx->mysql_thd);
+	tablebuf[bufend - tablebuf] = '\0';
+
+	strcat(fk_def, tablebuf);
+	strcat(fk_def, " (");
+
+	for(i = 0; i < foreign->n_fields; i++) {
+		char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+		bufend = innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->referenced_col_names[i],
+				strlen(foreign->referenced_col_names[i]),
+				trx->mysql_thd);
+		buf[bufend - buf] = '\0';
+		strcat(fk_def, buf);
+		if (i < (uint)foreign->n_fields-1) {
+			strcat(fk_def, (char *)",");
+		}
+	}
+	strcat(fk_def, (char *)")");
+
+	return fk_def;
+}
+
+/********************************************************************//**
+Convert foreign key column names from data dictionary to SQL-layer.
+*/
+static
+void
+dict_foreign_def_get_fields(
+/*========================*/
+	dict_foreign_t*	foreign,/*!< in: foreign */
+	trx_t*		trx,	/*!< in: trx */
+	char**		field,  /*!< out: foreign column */
+	char**		field2, /*!< out: referenced column */
+	ulint		col_no) /*!< in: column number */
+{
+	char* bufend;
+	char* fieldbuf = (char *)mem_heap_alloc(foreign->heap, MAX_TABLE_NAME_LEN+1);
+	char* fieldbuf2 = (char *)mem_heap_alloc(foreign->heap, MAX_TABLE_NAME_LEN+1);
+
+	bufend = innobase_convert_name(fieldbuf, MAX_TABLE_NAME_LEN,
+			foreign->foreign_col_names[col_no],
+			strlen(foreign->foreign_col_names[col_no]),
+			trx->mysql_thd);
+
+	fieldbuf[bufend - fieldbuf] = '\0';
+
+	bufend = innobase_convert_name(fieldbuf2, MAX_TABLE_NAME_LEN,
+			foreign->referenced_col_names[col_no],
+			strlen(foreign->referenced_col_names[col_no]),
+			trx->mysql_thd);
+
+	fieldbuf2[bufend - fieldbuf2] = '\0';
+	*field = fieldbuf;
+	*field2 = fieldbuf2;
+}
+
+/********************************************************************//**
+Add a foreign key definition to the data dictionary tables.
+@return error code or DB_SUCCESS */
+dberr_t
+dict_create_add_foreign_to_dictionary(
+/*==================================*/
+	const char*		name,	/*!< in: table name */
+	const dict_foreign_t*	foreign,/*!< in: foreign key */
+	trx_t*			trx)	/*!< in/out: dictionary transaction */
+{
+	dberr_t		error;
+
+	DBUG_ENTER("dict_create_add_foreign_to_dictionary");
+
+	pars_info_t*	info = pars_info_create();
+
+	pars_info_add_str_literal(info, "id", foreign->id);
+
+	pars_info_add_str_literal(info, "for_name", name);
+
+	pars_info_add_str_literal(info, "ref_name",
+				  foreign->referenced_table_name);
+
+	pars_info_add_int4_literal(info, "n_cols",
+				   ulint(foreign->n_fields)
+				   | (ulint(foreign->type) << 24));
+
+	DBUG_PRINT("dict_create_add_foreign_to_dictionary",
+		   ("'%s', '%s', '%s', %d", foreign->id, name,
+		    foreign->referenced_table_name,
+		    foreign->n_fields + (foreign->type << 24)));
+
+	error = dict_foreign_eval_sql(info,
+				      "PROCEDURE P () IS\n"
+				      "BEGIN\n"
+				      "INSERT INTO SYS_FOREIGN VALUES"
+				      "(:id, :for_name, :ref_name, :n_cols);\n"
+				      "END;\n"
+				      , name, foreign->id, trx);
+
+	if (error != DB_SUCCESS) {
+
+		if (error == DB_DUPLICATE_KEY) {
+			char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+			char	tablename[MAX_TABLE_NAME_LEN + 1] = "";
+			char*	fk_def;
+
+			innobase_convert_name(tablename, MAX_TABLE_NAME_LEN,
+				name, strlen(name), trx->mysql_thd);
+
+			innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->id, strlen(foreign->id), trx->mysql_thd);
+
+			fk_def = dict_foreign_def_get((dict_foreign_t*)foreign, trx);
+
+			ib_push_warning(trx, error,
+				"Create or Alter table %s with foreign key constraint"
+				" failed. Foreign key constraint %s"
+				" already exists on data dictionary."
+				" Foreign key constraint names need to be unique in database."
+				" Error in foreign key definition: %s.",
+				tablename, buf, fk_def);
+		}
+
+		DBUG_RETURN(error);
+	}
+
+	for (ulint i = 0; i < foreign->n_fields; i++) {
+		error = dict_create_add_foreign_field_to_dictionary(
+			i, name, foreign, trx);
+
+		if (error != DB_SUCCESS) {
+			char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+			char	tablename[MAX_TABLE_NAME_LEN + 1] = "";
+			char*	field=NULL;
+			char*	field2=NULL;
+			char*	fk_def;
+
+			innobase_convert_name(tablename, MAX_TABLE_NAME_LEN,
+				name, strlen(name), trx->mysql_thd);
+			innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->id, strlen(foreign->id), trx->mysql_thd);
+			fk_def = dict_foreign_def_get((dict_foreign_t*)foreign, trx);
+			dict_foreign_def_get_fields((dict_foreign_t*)foreign, trx, &field, &field2, i);
+
+			ib_push_warning(trx, error,
+				"Create or Alter table %s with foreign key constraint"
+				" failed. Error adding foreign  key constraint name %s"
+				" fields %s or %s to the dictionary."
+				" Error in foreign key definition: %s.",
+				tablename, buf, i+1, fk_def);
+
+			DBUG_RETURN(error);
+		}
+	}
+
+	DBUG_RETURN(error);
+}
+
+/** Check if a foreign constraint is on the given column name.
+@param[in]	col_name	column name to be searched for fk constraint
+@param[in]	table		table to which foreign key constraint belongs
+@return true if fk constraint is present on the table, false otherwise. */
+static
+bool
+dict_foreign_base_for_stored(
+	const char*		col_name,
+	const dict_table_t*	table)
+{
+	/* Loop through each stored column and check if its base column has
+	the same name as the column name being checked */
+	dict_s_col_list::const_iterator	it;
+	for (it = table->s_cols->begin();
+	     it != table->s_cols->end(); ++it) {
+		dict_s_col_t	s_col = *it;
+
+		for (ulint j = 0; j < s_col.num_base; j++) {
+			if (strcmp(col_name, dict_table_get_col_name(
+						table,
+						s_col.base_col[j]->ind)) == 0) {
+				return(true);
+			}
+		}
+	}
+
+	return(false);
+}
+
+/** Check if a foreign constraint is on columns served as base columns
+of any stored column. This is to prevent creating SET NULL or CASCADE
+constraint on such columns
+@param[in]	local_fk_set	set of foreign key objects, to be added to
+the dictionary tables
+@param[in]	table		table to which the foreign key objects in
+local_fk_set belong to
+@return true if yes, otherwise, false */
+bool
+dict_foreigns_has_s_base_col(
+	const dict_foreign_set&	local_fk_set,
+	const dict_table_t*	table)
+{
+	dict_foreign_t*	foreign;
+
+	if (table->s_cols == NULL) {
+		return (false);
+	}
+
+	for (dict_foreign_set::const_iterator it = local_fk_set.begin();
+	     it != local_fk_set.end(); ++it) {
+
+		foreign = *it;
+		ulint	type = foreign->type;
+
+		type &= ~(DICT_FOREIGN_ON_DELETE_NO_ACTION
+			  | DICT_FOREIGN_ON_UPDATE_NO_ACTION);
+
+		if (type == 0) {
+			continue;
+		}
+
+		for (ulint i = 0; i < foreign->n_fields; i++) {
+			/* Check if the constraint is on a column that
+			is a base column of any stored column */
+			if (dict_foreign_base_for_stored(
+				foreign->foreign_col_names[i], table)) {
+				return(true);
+			}
+		}
+	}
+
+	return(false);
+}
+
+/** Adds the given set of foreign key objects to the dictionary tables
+in the database. This function does not modify the dictionary cache. The
+caller must ensure that all foreign key objects contain a valid constraint
+name in foreign->id.
+@param[in]	local_fk_set	set of foreign key objects, to be added to
+the dictionary tables
+@param[in]	table		table to which the foreign key objects in
+local_fk_set belong to
+@param[in,out]	trx		transaction
+@return error code or DB_SUCCESS */
+dberr_t
+dict_create_add_foreigns_to_dictionary(
+/*===================================*/
+	const dict_foreign_set&	local_fk_set,
+	const dict_table_t*	table,
+	trx_t*			trx)
+{
+  ut_ad(dict_sys.locked());
+
+  if (!dict_sys.sys_foreign)
+  {
+    sql_print_error("InnoDB: Table SYS_FOREIGN not found"
+                    " in internal data dictionary");
+    return DB_ERROR;
+  }
+
+  for (auto fk : local_fk_set)
+    if (dberr_t error=
+        dict_create_add_foreign_to_dictionary(table->name.m_name, fk, trx))
+      return error;
+
+  return DB_SUCCESS;
+}
diff --git a/storage/innobase/dict/dict0defrag_bg.cc b/storage/innobase/dict/dict0defrag_bg.cc
new file mode 100644
index 00000000..bec6da8e
--- /dev/null
+++ b/storage/innobase/dict/dict0defrag_bg.cc
@@ -0,0 +1,434 @@
+/*****************************************************************************
+
+Copyright (c) 2016, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file dict/dict0defrag_bg.cc
+Defragmentation routines.
+
+Created 25/08/2016 Jan Lindström
+*******************************************************/
+
+#include "dict0dict.h"
+#include "dict0stats.h"
+#include "dict0stats_bg.h"
+#include "dict0defrag_bg.h"
+#include "btr0btr.h"
+#include "srv0start.h"
+#include "trx0trx.h"
+#include "lock0lock.h"
+#include "row0mysql.h"
+
+static mysql_mutex_t defrag_pool_mutex;
+
+/** Iterator type for iterating over the elements of objects of type
+defrag_pool_t. */
+typedef defrag_pool_t::iterator		defrag_pool_iterator_t;
+
+/** Pool where we store information on which tables are to be processed
+by background defragmentation. */
+defrag_pool_t			defrag_pool;
+
+
+/*****************************************************************//**
+Initialize the defrag pool, called once during thread initialization. */
+void
+dict_defrag_pool_init(void)
+/*=======================*/
+{
+	ut_ad(!srv_read_only_mode);
+	mysql_mutex_init(0, &defrag_pool_mutex, nullptr);
+}
+
+/*****************************************************************//**
+Free the resources occupied by the defrag pool, called once during
+thread de-initialization. */
+void
+dict_defrag_pool_deinit(void)
+/*=========================*/
+{
+	ut_ad(!srv_read_only_mode);
+
+	mysql_mutex_destroy(&defrag_pool_mutex);
+}
+
+/*****************************************************************//**
+Get an index from the auto defrag pool. The returned index id is removed
+from the pool.
+@return true if the pool was non-empty and "id" was set, false otherwise */
+static
+bool
+dict_stats_defrag_pool_get(
+/*=======================*/
+	table_id_t*	table_id,	/*!< out: table id, or unmodified if
+					list is empty */
+	index_id_t*	index_id)	/*!< out: index id, or unmodified if
+					list is empty */
+{
+	ut_ad(!srv_read_only_mode);
+
+	mysql_mutex_lock(&defrag_pool_mutex);
+
+	if (defrag_pool.empty()) {
+		mysql_mutex_unlock(&defrag_pool_mutex);
+		return(false);
+	}
+
+	defrag_pool_item_t& item = defrag_pool.back();
+	*table_id = item.table_id;
+	*index_id = item.index_id;
+
+	defrag_pool.pop_back();
+
+	mysql_mutex_unlock(&defrag_pool_mutex);
+
+	return(true);
+}
+
+/*****************************************************************//**
+Add an index in a table to the defrag pool, which is processed by the
+background stats gathering thread. Only the table id and index id are
+added to the list, so the table can be closed after being enqueued and
+it will be opened when needed. If the table or index does not exist later
+(has been DROPped), then it will be removed from the pool and skipped. */
+void
+dict_stats_defrag_pool_add(
+/*=======================*/
+	const dict_index_t*	index)	/*!< in: table to add */
+{
+	defrag_pool_item_t item;
+
+	ut_ad(!srv_read_only_mode);
+
+	mysql_mutex_lock(&defrag_pool_mutex);
+
+	/* quit if already in the list */
+	for (defrag_pool_iterator_t iter = defrag_pool.begin();
+	     iter != defrag_pool.end();
+	     ++iter) {
+		if ((*iter).table_id == index->table->id
+		    && (*iter).index_id == index->id) {
+			mysql_mutex_unlock(&defrag_pool_mutex);
+			return;
+		}
+	}
+
+	item.table_id = index->table->id;
+	item.index_id = index->id;
+	defrag_pool.push_back(item);
+	if (defrag_pool.size() == 1) {
+		/* Kick off dict stats optimizer work */
+		dict_stats_schedule_now();
+	}
+	mysql_mutex_unlock(&defrag_pool_mutex);
+}
+
+/*****************************************************************//**
+Delete a given index from the auto defrag pool. */
+void
+dict_stats_defrag_pool_del(
+/*=======================*/
+	const dict_table_t*	table,	/*!<in: if given, remove
+					all entries for the table */
+	const dict_index_t*	index)	/*!< in: if given, remove this index */
+{
+	ut_a((table && !index) || (!table && index));
+	ut_ad(!srv_read_only_mode);
+	ut_ad(dict_sys.frozen());
+
+	mysql_mutex_lock(&defrag_pool_mutex);
+
+	defrag_pool_iterator_t iter = defrag_pool.begin();
+	while (iter != defrag_pool.end()) {
+		if ((table && (*iter).table_id == table->id)
+		    || (index
+			&& (*iter).table_id == index->table->id
+			&& (*iter).index_id == index->id)) {
+			/* erase() invalidates the iterator */
+			iter = defrag_pool.erase(iter);
+			if (index)
+				break;
+		} else {
+			iter++;
+		}
+	}
+
+	mysql_mutex_unlock(&defrag_pool_mutex);
+}
+
+/*****************************************************************//**
+Get the first index that has been added for updating persistent defrag
+stats and eventually save its stats. */
+static void dict_stats_process_entry_from_defrag_pool(THD *thd)
+{
+  table_id_t table_id;
+  index_id_t index_id;
+
+  ut_ad(!srv_read_only_mode);
+
+  /* pop the first index from the auto defrag pool */
+  if (!dict_stats_defrag_pool_get(&table_id, &index_id))
+    /* no index in defrag pool */
+    return;
+
+  /* If the table is no longer cached, we've already lost the in
+  memory stats so there's nothing really to write to disk. */
+  MDL_ticket *mdl= nullptr;
+  if (dict_table_t *table=
+      dict_table_open_on_id(table_id, false, DICT_TABLE_OP_OPEN_ONLY_IF_CACHED,
+                            thd, &mdl))
+  {
+    if (dict_index_t *index= !table->corrupted
+        ? dict_table_find_index_on_id(table, index_id) : nullptr)
+      if (index->is_btree())
+        dict_stats_save_defrag_stats(index);
+    dict_table_close(table, false, thd, mdl);
+  }
+}
+
+/**
+Get the first index that has been added for updating persistent defrag
+stats and eventually save its stats. */
+void dict_defrag_process_entries_from_defrag_pool(THD *thd)
+{
+  while (!defrag_pool.empty())
+    dict_stats_process_entry_from_defrag_pool(thd);
+}
+
+/*********************************************************************//**
+Save defragmentation result.
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_save_defrag_summary(dict_index_t *index, THD *thd)
+{
+  if (index->is_ibuf())
+    return DB_SUCCESS;
+
+  MDL_ticket *mdl_table= nullptr, *mdl_index= nullptr;
+  dict_table_t *table_stats= dict_table_open_on_name(TABLE_STATS_NAME, false,
+                                                     DICT_ERR_IGNORE_NONE);
+  if (table_stats)
+  {
+    dict_sys.freeze(SRW_LOCK_CALL);
+    table_stats= dict_acquire_mdl_shared<false>(table_stats, thd, &mdl_table);
+    dict_sys.unfreeze();
+  }
+  if (!table_stats || strcmp(table_stats->name.m_name, TABLE_STATS_NAME))
+  {
+release_and_exit:
+    if (table_stats)
+      dict_table_close(table_stats, false, thd, mdl_table);
+    return DB_STATS_DO_NOT_EXIST;
+  }
+
+  dict_table_t *index_stats= dict_table_open_on_name(INDEX_STATS_NAME, false,
+                                                     DICT_ERR_IGNORE_NONE);
+  if (index_stats)
+  {
+    dict_sys.freeze(SRW_LOCK_CALL);
+    index_stats= dict_acquire_mdl_shared<false>(index_stats, thd, &mdl_index);
+    dict_sys.unfreeze();
+  }
+  if (!index_stats)
+    goto release_and_exit;
+  if (strcmp(index_stats->name.m_name, INDEX_STATS_NAME))
+  {
+    dict_table_close(index_stats, false, thd, mdl_index);
+    goto release_and_exit;
+  }
+
+  trx_t *trx= trx_create();
+  trx->mysql_thd= thd;
+  trx_start_internal(trx);
+  dberr_t ret= trx->read_only
+    ? DB_READ_ONLY
+    : lock_table_for_trx(table_stats, trx, LOCK_X);
+  if (ret == DB_SUCCESS)
+    ret= lock_table_for_trx(index_stats, trx, LOCK_X);
+  row_mysql_lock_data_dictionary(trx);
+  if (ret == DB_SUCCESS)
+    ret= dict_stats_save_index_stat(index, time(nullptr), "n_pages_freed",
+                                    index->stat_defrag_n_pages_freed,
+                                    nullptr,
+                                    "Number of pages freed during"
+                                    " last defragmentation run.",
+                                    trx);
+  if (ret == DB_SUCCESS)
+    trx->commit();
+  else
+    trx->rollback();
+
+  if (table_stats)
+    dict_table_close(table_stats, true, thd, mdl_table);
+  if (index_stats)
+    dict_table_close(index_stats, true, thd, mdl_index);
+
+  row_mysql_unlock_data_dictionary(trx);
+  trx->free();
+
+  return ret;
+}
+
+/**************************************************************//**
+Gets the number of reserved and used pages in a B-tree.
+@return	number of pages reserved, or ULINT_UNDEFINED if the index
+is unavailable */
+static
+ulint
+btr_get_size_and_reserved(
+	dict_index_t*	index,	/*!< in: index */
+	ulint		flag,	/*!< in: BTR_N_LEAF_PAGES or BTR_TOTAL_SIZE */
+	ulint*		used,	/*!< out: number of pages used (<= reserved) */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction where index
+				is s-latched */
+{
+	ulint		dummy;
+
+	ut_ad(mtr->memo_contains(index->lock, MTR_MEMO_SX_LOCK));
+	ut_a(flag == BTR_N_LEAF_PAGES || flag == BTR_TOTAL_SIZE);
+
+	if (index->page == FIL_NULL
+	    || dict_index_is_online_ddl(index)
+	    || !index->is_committed()
+	    || !index->table->space) {
+		return(ULINT_UNDEFINED);
+	}
+
+	dberr_t err;
+	buf_block_t* root = btr_root_block_get(index, RW_SX_LATCH, mtr, &err);
+	*used = 0;
+	if (!root) {
+		return ULINT_UNDEFINED;
+	}
+
+	mtr->x_lock_space(index->table->space);
+
+	ulint n = fseg_n_reserved_pages(*root, PAGE_HEADER + PAGE_BTR_SEG_LEAF
+					+ root->page.frame, used, mtr);
+	if (flag == BTR_TOTAL_SIZE) {
+		n += fseg_n_reserved_pages(*root,
+					   PAGE_HEADER + PAGE_BTR_SEG_TOP
+					   + root->page.frame, &dummy, mtr);
+		*used += dummy;
+	}
+
+	return(n);
+}
+
+/*********************************************************************//**
+Save defragmentation stats for a given index.
+@return DB_SUCCESS or error code */
+dberr_t
+dict_stats_save_defrag_stats(
+/*============================*/
+	dict_index_t*	index)	/*!< in: index */
+{
+  if (index->is_ibuf())
+    return DB_SUCCESS;
+  if (!index->is_readable())
+    return dict_stats_report_error(index->table, true);
+
+  const time_t now= time(nullptr);
+  mtr_t mtr;
+  ulint n_leaf_pages;
+  mtr.start();
+  mtr_sx_lock_index(index, &mtr);
+  ulint n_leaf_reserved= btr_get_size_and_reserved(index, BTR_N_LEAF_PAGES,
+                                                   &n_leaf_pages, &mtr);
+  mtr.commit();
+
+  if (n_leaf_reserved == ULINT_UNDEFINED)
+    return DB_SUCCESS;
+
+  THD *thd= current_thd;
+  MDL_ticket *mdl_table= nullptr, *mdl_index= nullptr;
+  dict_table_t* table_stats= dict_table_open_on_name(TABLE_STATS_NAME, false,
+                                                     DICT_ERR_IGNORE_NONE);
+  if (table_stats)
+  {
+    dict_sys.freeze(SRW_LOCK_CALL);
+    table_stats= dict_acquire_mdl_shared<false>(table_stats, thd, &mdl_table);
+    dict_sys.unfreeze();
+  }
+  if (!table_stats || strcmp(table_stats->name.m_name, TABLE_STATS_NAME))
+  {
+release_and_exit:
+    if (table_stats)
+      dict_table_close(table_stats, false, thd, mdl_table);
+    return DB_STATS_DO_NOT_EXIST;
+  }
+
+  dict_table_t *index_stats= dict_table_open_on_name(INDEX_STATS_NAME, false,
+                                                     DICT_ERR_IGNORE_NONE);
+  if (index_stats)
+  {
+    dict_sys.freeze(SRW_LOCK_CALL);
+    index_stats= dict_acquire_mdl_shared<false>(index_stats, thd, &mdl_index);
+    dict_sys.unfreeze();
+  }
+  if (!index_stats)
+    goto release_and_exit;
+
+  if (strcmp(index_stats->name.m_name, INDEX_STATS_NAME))
+  {
+    dict_table_close(index_stats, false, thd, mdl_index);
+    goto release_and_exit;
+  }
+
+  trx_t *trx= trx_create();
+  trx->mysql_thd= thd;
+  trx_start_internal(trx);
+  dberr_t ret= trx->read_only
+    ? DB_READ_ONLY
+    : lock_table_for_trx(table_stats, trx, LOCK_X);
+  if (ret == DB_SUCCESS)
+    ret= lock_table_for_trx(index_stats, trx, LOCK_X);
+
+  row_mysql_lock_data_dictionary(trx);
+
+  if (ret == DB_SUCCESS)
+    ret= dict_stats_save_index_stat(index, now, "n_page_split",
+                                    index->stat_defrag_n_page_split, nullptr,
+                                    "Number of new page splits on leaves"
+                                    " since last defragmentation.", trx);
+
+  if (ret == DB_SUCCESS)
+    ret= dict_stats_save_index_stat(index, now, "n_leaf_pages_defrag",
+                                    n_leaf_pages, nullptr,
+                                    "Number of leaf pages when"
+                                    " this stat is saved to disk", trx);
+
+  if (ret == DB_SUCCESS)
+    ret= dict_stats_save_index_stat(index, now, "n_leaf_pages_reserved",
+                                    n_leaf_reserved, nullptr,
+                                    "Number of pages reserved for"
+                                    " this index leaves"
+                                    " when this stat is saved to disk", trx);
+
+  if (ret == DB_SUCCESS)
+    trx->commit();
+  else
+    trx->rollback();
+
+  if (table_stats)
+    dict_table_close(table_stats, true, thd, mdl_table);
+  if (index_stats)
+    dict_table_close(index_stats, true, thd, mdl_index);
+  row_mysql_unlock_data_dictionary(trx);
+  trx->free();
+
+  return ret;
+}
diff --git a/storage/innobase/dict/dict0dict.cc b/storage/innobase/dict/dict0dict.cc
new file mode 100644
index 00000000..5bc7ab6e
--- /dev/null
+++ b/storage/innobase/dict/dict0dict.cc
@@ -0,0 +1,4859 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2013, 2023, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/******************************************************************//**
+@file dict/dict0dict.cc
+Data dictionary system
+
+Created 1/8/1996 Heikki Tuuri
+***********************************************************************/
+
+#include <my_config.h>
+#include <string>
+
+#include "ha_prototypes.h"
+#include <mysqld.h>
+#include <strfunc.h>
+
+#include "dict0dict.h"
+#include "fts0fts.h"
+#include "fil0fil.h"
+#include <algorithm>
+#include "sql_class.h"
+#include "sql_table.h"
+#include <mysql/service_thd_mdl.h>
+
+#include "btr0btr.h"
+#include "btr0cur.h"
+#include "btr0sea.h"
+#include "buf0buf.h"
+#include "data0type.h"
+#include "dict0boot.h"
+#include "dict0load.h"
+#include "dict0crea.h"
+#include "dict0mem.h"
+#include "dict0stats.h"
+#include "fts0fts.h"
+#include "fts0types.h"
+#include "lock0lock.h"
+#include "mach0data.h"
+#include "mem0mem.h"
+#include "page0page.h"
+#include "page0zip.h"
+#include "pars0pars.h"
+#include "pars0sym.h"
+#include "que0que.h"
+#include "rem0cmp.h"
+#include "row0log.h"
+#include "row0merge.h"
+#include "row0mysql.h"
+#include "row0upd.h"
+#include "srv0mon.h"
+#include "srv0start.h"
+#include "trx0undo.h"
+#include "trx0purge.h"
+
+#include <vector>
+#include <algorithm>
+
+/** the dictionary system */
+dict_sys_t	dict_sys;
+
+/** System table names; @see dict_system_id_t */
+const span<const char> dict_sys_t::SYS_TABLE[]=
+{
+  {C_STRING_WITH_LEN("SYS_TABLES")},{C_STRING_WITH_LEN("SYS_INDEXES")},
+  {C_STRING_WITH_LEN("SYS_COLUMNS")},{C_STRING_WITH_LEN("SYS_FIELDS")},
+  {C_STRING_WITH_LEN("SYS_FOREIGN")},{C_STRING_WITH_LEN("SYS_FOREIGN_COLS")},
+  {C_STRING_WITH_LEN("SYS_VIRTUAL")}
+};
+
+/** Diagnostic message for exceeding the mutex_lock_wait() timeout */
+const char dict_sys_t::fatal_msg[]=
+  "innodb_fatal_semaphore_wait_threshold was exceeded for dict_sys.latch. "
+  "Please refer to "
+  "https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/";
+
+/** Percentage of compression failures that are allowed in a single
+round */
+ulong	zip_failure_threshold_pct = 5;
+
+/** Maximum percentage of a page that can be allowed as a pad to avoid
+compression failures */
+ulong	zip_pad_max = 50;
+
+#define	DICT_HEAP_SIZE		100	/*!< initial memory heap size when
+					creating a table or index object */
+#define DICT_POOL_PER_TABLE_HASH 512	/*!< buffer pool max size per table
+					hash table fixed size in bytes */
+#define DICT_POOL_PER_VARYING	4	/*!< buffer pool max size per data
+					dictionary varying size in bytes */
+
+/** Identifies generated InnoDB foreign key names */
+static char	dict_ibfk[] = "_ibfk_";
+
+/*******************************************************************//**
+Tries to find column names for the index and sets the col field of the
+index.
+@param[in]	index	index
+@param[in]	add_v	new virtual columns added along with an add index call
+@return whether the column names were found */
+static
+bool
+dict_index_find_cols(
+	dict_index_t*		index,
+	const dict_add_v_col_t*	add_v);
+/*******************************************************************//**
+Builds the internal dictionary cache representation for a clustered
+index, containing also system fields not defined by the user.
+@return own: the internal representation of the clustered index */
+static
+dict_index_t*
+dict_index_build_internal_clust(
+/*============================*/
+	dict_index_t*		index);	/*!< in: user representation of
+					a clustered index */
+/*******************************************************************//**
+Builds the internal dictionary cache representation for a non-clustered
+index, containing also system fields not defined by the user.
+@return own: the internal representation of the non-clustered index */
+static
+dict_index_t*
+dict_index_build_internal_non_clust(
+/*================================*/
+	dict_index_t*		index);	/*!< in: user representation of
+					a non-clustered index */
+/**********************************************************************//**
+Builds the internal dictionary cache representation for an FTS index.
+@return own: the internal representation of the FTS index */
+static
+dict_index_t*
+dict_index_build_internal_fts(
+/*==========================*/
+	dict_index_t*	index);	/*!< in: user representation of an FTS index */
+
+/**********************************************************************//**
+Removes an index from the dictionary cache. */
+static
+void
+dict_index_remove_from_cache_low(
+/*=============================*/
+	dict_table_t*	table,		/*!< in/out: table */
+	dict_index_t*	index,		/*!< in, own: index */
+	ibool		lru_evict);	/*!< in: TRUE if page being evicted
+					to make room in the table LRU list */
+#ifdef UNIV_DEBUG
+/**********************************************************************//**
+Validate the dictionary table LRU list.
+@return TRUE if validate OK */
+static
+ibool
+dict_lru_validate(void);
+/*===================*/
+#endif /* UNIV_DEBUG */
+
+/* Stream for storing detailed information about the latest foreign key
+and unique key errors. Only created if !srv_read_only_mode */
+FILE*	dict_foreign_err_file		= NULL;
+/* mutex protecting the foreign and unique error buffers */
+mysql_mutex_t dict_foreign_err_mutex;
+
+/********************************************************************//**
+Checks if the database name in two table names is the same.
+@return TRUE if same db name */
+ibool
+dict_tables_have_same_db(
+/*=====================*/
+	const char*	name1,	/*!< in: table name in the form
+				dbname '/' tablename */
+	const char*	name2)	/*!< in: table name in the form
+				dbname '/' tablename */
+{
+	for (; *name1 == *name2; name1++, name2++) {
+		if (*name1 == '/') {
+			return(TRUE);
+		}
+		ut_a(*name1); /* the names must contain '/' */
+	}
+	return(FALSE);
+}
+
+/********************************************************************//**
+Return the end of table name where we have removed dbname and '/'.
+@return table name */
+const char*
+dict_remove_db_name(
+/*================*/
+	const char*	name)	/*!< in: table name in the form
+				dbname '/' tablename */
+{
+	const char*	s = strchr(name, '/');
+	ut_a(s);
+
+	return(s + 1);
+}
+
+/** Decrement the count of open handles */
+void dict_table_close(dict_table_t *table)
+{
+  if (table->get_ref_count() == 1 &&
+      dict_stats_is_persistent_enabled(table) &&
+      strchr(table->name.m_name, '/'))
+  {
+    /* It looks like we are closing the last handle. The user could
+    have executed FLUSH TABLES in order to have the statistics reloaded
+    from the InnoDB persistent statistics tables. We must acquire
+    exclusive dict_sys.latch to prevent a race condition with another
+    thread concurrently acquiring a handle on the table. */
+    dict_sys.lock(SRW_LOCK_CALL);
+    if (table->release())
+    {
+      table->stats_mutex_lock();
+      if (table->get_ref_count() == 0)
+        dict_stats_deinit(table);
+      table->stats_mutex_unlock();
+    }
+    dict_sys.unlock();
+  }
+  else
+    table->release();
+}
+
+/** Decrements the count of open handles of a table.
+@param[in,out]	table		table
+@param[in]	dict_locked	whether dict_sys.latch is being held
+@param[in]	thd		thread to release MDL
+@param[in]	mdl		metadata lock or NULL if the thread
+				is a foreground one. */
+void
+dict_table_close(
+	dict_table_t*	table,
+	bool		dict_locked,
+	THD*		thd,
+	MDL_ticket*	mdl)
+{
+  if (!dict_locked)
+    dict_table_close(table);
+  else
+  {
+    if (table->release() && dict_stats_is_persistent_enabled(table) &&
+	strchr(table->name.m_name, '/'))
+    {
+      /* Force persistent stats re-read upon next open of the table so
+      that FLUSH TABLE can be used to forcibly fetch stats from disk if
+      they have been manually modified. */
+      table->stats_mutex_lock();
+      if (table->get_ref_count() == 0)
+        dict_stats_deinit(table);
+      table->stats_mutex_unlock();
+    }
+
+    ut_ad(dict_lru_validate());
+    ut_ad(dict_sys.find(table));
+  }
+
+  if (!thd || !mdl);
+  else if (MDL_context *mdl_context= static_cast<MDL_context*>
+           (thd_mdl_context(thd)))
+    mdl_context->release_lock(mdl);
+}
+
+/** Check if the table has a given (non_virtual) column.
+@param[in]	table		table object
+@param[in]	col_name	column name
+@param[in]	col_nr		column number guessed, 0 as default
+@return column number if the table has the specified column,
+otherwise table->n_def */
+ulint
+dict_table_has_column(
+	const dict_table_t*	table,
+	const char*		col_name,
+	ulint			col_nr)
+{
+	ulint		col_max = table->n_def;
+
+	ut_ad(table);
+	ut_ad(col_name);
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+
+	if (col_nr < col_max
+	    && innobase_strcasecmp(
+		col_name, dict_table_get_col_name(table, col_nr)) == 0) {
+		return(col_nr);
+	}
+
+	/** The order of column may changed, check it with other columns */
+	for (ulint i = 0; i < col_max; i++) {
+		if (i != col_nr
+		    && innobase_strcasecmp(
+			col_name, dict_table_get_col_name(table, i)) == 0) {
+
+			return(i);
+		}
+	}
+
+	return(col_max);
+}
+
+/** Retrieve the column name.
+@param[in]	table	the table of this column */
+const char* dict_col_t::name(const dict_table_t& table) const
+{
+	ut_ad(table.magic_n == DICT_TABLE_MAGIC_N);
+
+	size_t col_nr;
+	const char *s;
+
+	if (is_virtual()) {
+		col_nr = size_t(reinterpret_cast<const dict_v_col_t*>(this)
+				- table.v_cols);
+		ut_ad(col_nr < table.n_v_def);
+		s = table.v_col_names;
+	} else {
+		col_nr = size_t(this - table.cols);
+		ut_ad(col_nr < table.n_def);
+		s = table.col_names;
+	}
+
+	if (s) {
+		for (size_t i = 0; i < col_nr; i++) {
+			s += strlen(s) + 1;
+		}
+	}
+
+	return(s);
+}
+
+/** Returns a virtual column's name.
+@param[in]	table	target table
+@param[in]	col_nr	virtual column number (nth virtual column)
+@return column name or NULL if column number out of range. */
+const char*
+dict_table_get_v_col_name(
+	const dict_table_t*	table,
+	ulint			col_nr)
+{
+	const char*	s;
+
+	ut_ad(table);
+	ut_ad(col_nr < table->n_v_def);
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+
+	if (col_nr >= table->n_v_def) {
+		return(NULL);
+	}
+
+	s = table->v_col_names;
+
+	if (s != NULL) {
+		for (ulint i = 0; i < col_nr; i++) {
+			s += strlen(s) + 1;
+		}
+	}
+
+	return(s);
+}
+
+/** Search virtual column's position in InnoDB according to its position
+in original table's position
+@param[in]	table	target table
+@param[in]	col_nr	column number (nth column in the MySQL table)
+@return virtual column's position in InnoDB, ULINT_UNDEFINED if not find */
+static
+ulint
+dict_table_get_v_col_pos_for_mysql(
+	const dict_table_t*	table,
+	ulint			col_nr)
+{
+	ulint	i;
+
+	ut_ad(table);
+	ut_ad(col_nr < static_cast<ulint>(table->n_t_def));
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+
+	for (i = 0; i < table->n_v_def; i++) {
+		if (col_nr == dict_get_v_col_mysql_pos(
+				table->v_cols[i].m_col.ind)) {
+			break;
+		}
+	}
+
+	if (i == table->n_v_def) {
+		return(ULINT_UNDEFINED);
+	}
+
+	return(i);
+}
+
+/** Returns a virtual column's name according to its original
+MySQL table position.
+@param[in]	table	target table
+@param[in]	col_nr	column number (nth column in the table)
+@return column name. */
+static
+const char*
+dict_table_get_v_col_name_mysql(
+	const dict_table_t*	table,
+	ulint			col_nr)
+{
+	ulint	i = dict_table_get_v_col_pos_for_mysql(table, col_nr);
+
+	if (i == ULINT_UNDEFINED) {
+		return(NULL);
+	}
+
+	return(dict_table_get_v_col_name(table, i));
+}
+
+/** Get nth virtual column according to its original MySQL table position
+@param[in]	table	target table
+@param[in]	col_nr	column number in MySQL Table definition
+@return dict_v_col_t ptr */
+dict_v_col_t*
+dict_table_get_nth_v_col_mysql(
+	const dict_table_t*	table,
+	ulint			col_nr)
+{
+	ulint	i = dict_table_get_v_col_pos_for_mysql(table, col_nr);
+
+	if (i == ULINT_UNDEFINED) {
+		return(NULL);
+	}
+
+	return(dict_table_get_nth_v_col(table, i));
+}
+
+
+/** Get all the FTS indexes on a table.
+@param[in]	table	table
+@param[out]	indexes	all FTS indexes on this table
+@return number of FTS indexes */
+ulint
+dict_table_get_all_fts_indexes(
+	const dict_table_t*	table,
+	ib_vector_t*		indexes)
+{
+	dict_index_t* index;
+
+	ut_a(ib_vector_size(indexes) == 0);
+
+	for (index = dict_table_get_first_index(table);
+	     index;
+	     index = dict_table_get_next_index(index)) {
+
+		if (index->type == DICT_FTS) {
+			ib_vector_push(indexes, &index);
+		}
+	}
+
+	return(ib_vector_size(indexes));
+}
+
+/** Looks for column n in an index.
+@param[in]	index		index
+@param[in]	n		column number
+@param[in]	inc_prefix	true=consider column prefixes too
+@param[in]	is_virtual	true==virtual column
+@param[out]	prefix_col_pos	col num if prefix
+@return position in internal representation of the index;
+ULINT_UNDEFINED if not contained */
+ulint
+dict_index_get_nth_col_or_prefix_pos(
+	const dict_index_t*	index,
+	ulint			n,
+	bool			inc_prefix,
+	bool			is_virtual,
+	ulint*			prefix_col_pos)
+{
+	const dict_field_t*	field;
+	const dict_col_t*	col;
+	ulint			pos;
+	ulint			n_fields;
+
+	ut_ad(index);
+	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
+
+	if (prefix_col_pos) {
+		*prefix_col_pos = ULINT_UNDEFINED;
+	}
+
+	if (is_virtual) {
+		col = &(dict_table_get_nth_v_col(index->table, n)->m_col);
+	} else {
+		col = dict_table_get_nth_col(index->table, n);
+	}
+
+	if (dict_index_is_clust(index)) {
+
+		return(dict_col_get_clust_pos(col, index));
+	}
+
+	n_fields = dict_index_get_n_fields(index);
+
+	for (pos = 0; pos < n_fields; pos++) {
+		field = dict_index_get_nth_field(index, pos);
+
+		if (col == field->col) {
+			if (prefix_col_pos) {
+				*prefix_col_pos = pos;
+			}
+			if (inc_prefix || field->prefix_len == 0) {
+				return(pos);
+			}
+		}
+	}
+
+	return(ULINT_UNDEFINED);
+}
+
+/** Check if the index contains a column or a prefix of that column.
+@param[in]	n		column number
+@param[in]	is_virtual	whether it is a virtual col
+@return whether the index contains the column or its prefix */
+bool dict_index_t::contains_col_or_prefix(ulint n, bool is_virtual) const
+{
+	ut_ad(magic_n == DICT_INDEX_MAGIC_N);
+
+	if (is_primary()) {
+		return(!is_virtual);
+	}
+
+	const dict_col_t* col = is_virtual
+		? &dict_table_get_nth_v_col(table, n)->m_col
+		: dict_table_get_nth_col(table, n);
+
+	for (ulint pos = 0; pos < n_fields; pos++) {
+		if (col == fields[pos].col) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/********************************************************************//**
+Looks for a matching field in an index. The column has to be the same. The
+column in index must be complete, or must contain a prefix longer than the
+column in index2. That is, we must be able to construct the prefix in index2
+from the prefix in index.
+@return position in internal representation of the index;
+ULINT_UNDEFINED if not contained */
+ulint
+dict_index_get_nth_field_pos(
+/*=========================*/
+	const dict_index_t*	index,	/*!< in: index from which to search */
+	const dict_index_t*	index2,	/*!< in: index */
+	ulint			n)	/*!< in: field number in index2 */
+{
+	const dict_field_t*	field;
+	const dict_field_t*	field2;
+	ulint			n_fields;
+	ulint			pos;
+
+	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
+
+	field2 = dict_index_get_nth_field(index2, n);
+
+	n_fields = dict_index_get_n_fields(index);
+
+	/* Are we looking for a MBR (Minimum Bound Box) field of
+	a spatial index */
+	bool	is_mbr_fld = (n == 0 && dict_index_is_spatial(index2));
+
+	for (pos = 0; pos < n_fields; pos++) {
+		field = dict_index_get_nth_field(index, pos);
+
+		/* The first field of a spatial index is a transformed
+		MBR (Minimum Bound Box) field made out of original column,
+		so its field->col still points to original cluster index
+		col, but the actual content is different. So we cannot
+		consider them equal if neither of them is MBR field */
+		if (pos == 0 && dict_index_is_spatial(index) && !is_mbr_fld) {
+			continue;
+		}
+
+		if (field->col == field2->col
+		    && (field->prefix_len == 0
+			|| (field->prefix_len >= field2->prefix_len
+			    && field2->prefix_len != 0))) {
+
+			return(pos);
+		}
+	}
+
+	return(ULINT_UNDEFINED);
+}
+
+/** Parse the table file name into table name and database name.
+@tparam        dict_frozen  whether the caller holds dict_sys.latch
+@param[in,out] db_name      database name buffer
+@param[in,out] tbl_name     table name buffer
+@param[out] db_name_len     database name length
+@param[out] tbl_name_len    table name length
+@return whether the table name is visible to SQL */
+template<bool dict_frozen>
+bool dict_table_t::parse_name(char (&db_name)[NAME_LEN + 1],
+                              char (&tbl_name)[NAME_LEN + 1],
+                              size_t *db_name_len, size_t *tbl_name_len) const
+{
+  char db_buf[MAX_DATABASE_NAME_LEN + 1];
+  char tbl_buf[MAX_TABLE_NAME_LEN + 1];
+
+  if (!dict_frozen)
+    dict_sys.freeze(SRW_LOCK_CALL); /* protect against renaming */
+  ut_ad(dict_sys.frozen());
+  const size_t db_len= name.dblen();
+  ut_ad(db_len <= MAX_DATABASE_NAME_LEN);
+
+  memcpy(db_buf, mdl_name.m_name, db_len);
+  db_buf[db_len]= 0;
+
+  size_t tbl_len= strlen(mdl_name.m_name + db_len + 1);
+  const bool is_temp= mdl_name.is_temporary();
+
+  if (is_temp);
+  else if (const char *is_part= static_cast<const char*>
+           (memchr(mdl_name.m_name + db_len + 1, '#', tbl_len)))
+    tbl_len= static_cast<size_t>(is_part - &mdl_name.m_name[db_len + 1]);
+
+  memcpy(tbl_buf, mdl_name.m_name + db_len + 1, tbl_len);
+  tbl_buf[tbl_len]= 0;
+
+  if (!dict_frozen)
+    dict_sys.unfreeze();
+
+  *db_name_len= filename_to_tablename(db_buf, db_name,
+                                      MAX_DATABASE_NAME_LEN + 1, true);
+
+  if (is_temp)
+    return false;
+
+  *tbl_name_len= filename_to_tablename(tbl_buf, tbl_name,
+                                       MAX_TABLE_NAME_LEN + 1, true);
+  return true;
+}
+
+template bool
+dict_table_t::parse_name<>(char(&)[NAME_LEN + 1], char(&)[NAME_LEN + 1],
+                           size_t*, size_t*) const;
+
+/** Acquire MDL shared for the table name.
+@tparam trylock whether to use non-blocking operation
+@param[in,out]  table           table object
+@param[in,out]  thd             background thread
+@param[out]     mdl             mdl ticket
+@param[in]      table_op        operation to perform when opening
+@return table object after locking MDL shared
+@retval nullptr if the table is not readable, or if trylock && MDL blocked */
+template<bool trylock>
+dict_table_t*
+dict_acquire_mdl_shared(dict_table_t *table,
+                        THD *thd,
+                        MDL_ticket **mdl,
+                        dict_table_op_t table_op)
+{
+  if (!table || !mdl)
+    return table;
+
+  MDL_context *mdl_context= static_cast<MDL_context*>(thd_mdl_context(thd));
+  size_t db_len;
+  dict_table_t *not_found= nullptr;
+
+  if (trylock)
+  {
+    dict_sys.freeze(SRW_LOCK_CALL);
+    db_len= dict_get_db_name_len(table->name.m_name);
+    dict_sys.unfreeze();
+  }
+  else
+  {
+    ut_ad(dict_sys.frozen_not_locked());
+    db_len= dict_get_db_name_len(table->name.m_name);
+  }
+
+  if (db_len == 0)
+    return table; /* InnoDB system tables are not covered by MDL */
+
+  if (!mdl_context)
+    return nullptr;
+
+  table_id_t table_id= table->id;
+  char db_buf[NAME_LEN + 1], db_buf1[NAME_LEN + 1];
+  char tbl_buf[NAME_LEN + 1], tbl_buf1[NAME_LEN + 1];
+  size_t tbl_len;
+  bool unaccessible= false;
+
+  if (!table->parse_name<!trylock>(db_buf, tbl_buf, &db_len, &tbl_len))
+    /* The name of an intermediate table starts with #sql */
+    return table;
+
+retry:
+  if (!unaccessible && (!table->is_readable() || table->corrupted))
+  {
+    if (*mdl)
+    {
+      mdl_context->release_lock(*mdl);
+      *mdl= nullptr;
+    }
+    unaccessible= true;
+  }
+
+  if (!trylock)
+    table->release();
+
+  if (unaccessible)
+    return nullptr;
+
+  if (!trylock)
+    dict_sys.unfreeze();
+
+  {
+    MDL_request request;
+    MDL_REQUEST_INIT(&request,MDL_key::TABLE, db_buf, tbl_buf, MDL_SHARED,
+                     MDL_EXPLICIT);
+    if (trylock
+        ? mdl_context->try_acquire_lock(&request)
+        : mdl_context->acquire_lock(&request,
+                                    /* FIXME: use compatible type, and maybe
+                                    remove this parameter altogether! */
+                                    static_cast<double>(global_system_variables
+                                                        .lock_wait_timeout)))
+    {
+      *mdl= nullptr;
+      if (trylock)
+        return nullptr;
+    }
+    else
+    {
+      *mdl= request.ticket;
+      if (trylock && !*mdl)
+        return nullptr;
+    }
+  }
+
+  dict_sys.freeze(SRW_LOCK_CALL);
+  table= dict_sys.find_table(table_id);
+  if (table)
+    table->acquire();
+  if (!table && table_op != DICT_TABLE_OP_OPEN_ONLY_IF_CACHED)
+  {
+    dict_sys.unfreeze();
+    dict_sys.lock(SRW_LOCK_CALL);
+    table= dict_load_table_on_id(table_id,
+                                 table_op == DICT_TABLE_OP_LOAD_TABLESPACE
+                                 ? DICT_ERR_IGNORE_RECOVER_LOCK
+                                 : DICT_ERR_IGNORE_FK_NOKEY);
+    if (table)
+      table->acquire();
+    dict_sys.unlock();
+    dict_sys.freeze(SRW_LOCK_CALL);
+  }
+
+  if (!table || !table->is_accessible())
+  {
+    table= nullptr;
+return_without_mdl:
+    if (trylock)
+      dict_sys.unfreeze();
+    if (*mdl)
+    {
+      mdl_context->release_lock(*mdl);
+      *mdl= nullptr;
+    }
+    return not_found;
+  }
+
+  size_t db1_len, tbl1_len;
+
+  if (!table->parse_name<true>(db_buf1, tbl_buf1, &db1_len, &tbl1_len))
+  {
+    /* The table was renamed to #sql prefix.
+    Release MDL (if any) for the old name and return. */
+    goto return_without_mdl;
+  }
+
+  if (*mdl)
+  {
+    if (db_len == db1_len && tbl_len == tbl1_len &&
+        !memcmp(db_buf, db_buf1, db_len) &&
+        !memcmp(tbl_buf, tbl_buf1, tbl_len))
+    {
+      if (trylock)
+        dict_sys.unfreeze();
+      return table;
+    }
+
+    /* The table was renamed. Release MDL for the old name and
+    try to acquire MDL for the new name. */
+    mdl_context->release_lock(*mdl);
+    *mdl= nullptr;
+  }
+
+  db_len= db1_len;
+  tbl_len= tbl1_len;
+
+  memcpy(tbl_buf, tbl_buf1, tbl_len + 1);
+  memcpy(db_buf, db_buf1, db_len + 1);
+  goto retry;
+}
+
+template dict_table_t* dict_acquire_mdl_shared<false>
+(dict_table_t*,THD*,MDL_ticket**,dict_table_op_t);
+template dict_table_t* dict_acquire_mdl_shared<true>
+(dict_table_t*,THD*,MDL_ticket**,dict_table_op_t);
+
+/** Look up a table by numeric identifier.
+@param[in]      table_id        table identifier
+@param[in]      dict_locked     data dictionary locked
+@param[in]      table_op        operation to perform when opening
+@param[in,out]  thd             background thread, or NULL to not acquire MDL
+@param[out]     mdl             mdl ticket, or NULL
+@return table, NULL if does not exist */
+dict_table_t *dict_table_open_on_id(table_id_t table_id, bool dict_locked,
+                                    dict_table_op_t table_op, THD *thd,
+                                    MDL_ticket **mdl)
+{
+  if (!dict_locked)
+    dict_sys.freeze(SRW_LOCK_CALL);
+
+  dict_table_t *table= dict_sys.find_table(table_id);
+
+  if (table)
+  {
+    table->acquire();
+    if (thd && !dict_locked)
+      table= dict_acquire_mdl_shared<false>(table, thd, mdl, table_op);
+  }
+  else if (table_op != DICT_TABLE_OP_OPEN_ONLY_IF_CACHED)
+  {
+    if (!dict_locked)
+    {
+      dict_sys.unfreeze();
+      dict_sys.lock(SRW_LOCK_CALL);
+    }
+    table= dict_load_table_on_id(table_id,
+                                 table_op == DICT_TABLE_OP_LOAD_TABLESPACE
+                                 ? DICT_ERR_IGNORE_RECOVER_LOCK
+                                 : DICT_ERR_IGNORE_FK_NOKEY);
+    if (table)
+      table->acquire();
+    if (!dict_locked)
+    {
+      dict_sys.unlock();
+      if (table && thd)
+      {
+        dict_sys.freeze(SRW_LOCK_CALL);
+        table= dict_acquire_mdl_shared<false>(table, thd, mdl, table_op);
+        dict_sys.unfreeze();
+      }
+      return table;
+    }
+  }
+
+  if (!dict_locked)
+    dict_sys.unfreeze();
+
+  return table;
+}
+
+/********************************************************************//**
+Looks for column n position in the clustered index.
+@return position in internal representation of the clustered index */
+unsigned
+dict_table_get_nth_col_pos(
+/*=======================*/
+	const dict_table_t*	table,	/*!< in: table */
+	ulint			n,	/*!< in: column number */
+	ulint*			prefix_col_pos)
+{
+  ulint pos= dict_index_get_nth_col_pos(dict_table_get_first_index(table),
+					n, prefix_col_pos);
+  DBUG_ASSERT(pos <= dict_index_t::MAX_N_FIELDS);
+  return static_cast<unsigned>(pos);
+}
+
+/********************************************************************//**
+Checks if a column is in the ordering columns of the clustered index of a
+table. Column prefixes are treated like whole columns.
+@return TRUE if the column, or its prefix, is in the clustered key */
+ibool
+dict_table_col_in_clustered_key(
+/*============================*/
+	const dict_table_t*	table,	/*!< in: table */
+	ulint			n)	/*!< in: column number */
+{
+	const dict_index_t*	index;
+	const dict_field_t*	field;
+	const dict_col_t*	col;
+	ulint			pos;
+	ulint			n_fields;
+
+	col = dict_table_get_nth_col(table, n);
+
+	index = dict_table_get_first_index(table);
+
+	n_fields = dict_index_get_n_unique(index);
+
+	for (pos = 0; pos < n_fields; pos++) {
+		field = dict_index_get_nth_field(index, pos);
+
+		if (col == field->col) {
+
+			return(TRUE);
+		}
+	}
+
+	return(FALSE);
+}
+
+/** Initialise the data dictionary cache. */
+void dict_sys_t::create()
+{
+  ut_ad(this == &dict_sys);
+  ut_ad(!is_initialised());
+  m_initialised= true;
+  UT_LIST_INIT(table_LRU, &dict_table_t::table_LRU);
+  UT_LIST_INIT(table_non_LRU, &dict_table_t::table_LRU);
+
+  const ulint hash_size = buf_pool_get_curr_size()
+    / (DICT_POOL_PER_TABLE_HASH * UNIV_WORD_SIZE);
+
+  table_hash.create(hash_size);
+  table_id_hash.create(hash_size);
+  temp_id_hash.create(hash_size);
+
+  latch.SRW_LOCK_INIT(dict_operation_lock_key);
+
+  if (!srv_read_only_mode)
+  {
+    dict_foreign_err_file= os_file_create_tmpfile();
+    ut_a(dict_foreign_err_file);
+  }
+
+  mysql_mutex_init(dict_foreign_err_mutex_key, &dict_foreign_err_mutex,
+                   nullptr);
+}
+
+
+void dict_sys_t::lock_wait(SRW_LOCK_ARGS(const char *file, unsigned line))
+{
+  ulonglong now= my_hrtime_coarse().val, old= 0;
+  if (latch_ex_wait_start.compare_exchange_strong
+      (old, now, std::memory_order_relaxed, std::memory_order_relaxed))
+  {
+    latch.wr_lock(SRW_LOCK_ARGS(file, line));
+    latch_ex_wait_start.store(0, std::memory_order_relaxed);
+    ut_ad(!latch_readers);
+    ut_ad(!latch_ex);
+    ut_d(latch_ex= pthread_self());
+    return;
+  }
+
+  ut_ad(old);
+  /* We could have old > now due to our use of my_hrtime_coarse(). */
+  ulong waited= old <= now ? static_cast<ulong>((now - old) / 1000000) : 0;
+  const ulong threshold= srv_fatal_semaphore_wait_threshold;
+
+  if (waited >= threshold)
+    ib::fatal() << fatal_msg;
+
+  if (waited > threshold / 4)
+    ib::warn() << "A long wait (" << waited
+               << " seconds) was observed for dict_sys.latch";
+  latch.wr_lock(SRW_LOCK_ARGS(file, line));
+  ut_ad(!latch_readers);
+  ut_ad(!latch_ex);
+  ut_d(latch_ex= pthread_self());
+}
+
+#ifdef UNIV_PFS_RWLOCK
+ATTRIBUTE_NOINLINE void dict_sys_t::unlock()
+{
+  ut_ad(latch_ex == pthread_self());
+  ut_ad(!latch_readers);
+  ut_d(latch_ex= 0);
+  latch.wr_unlock();
+}
+
+ATTRIBUTE_NOINLINE void dict_sys_t::freeze(const char *file, unsigned line)
+{
+  latch.rd_lock(file, line);
+  ut_ad(!latch_ex);
+  ut_d(latch_readers++);
+}
+
+ATTRIBUTE_NOINLINE void dict_sys_t::unfreeze()
+{
+  ut_ad(!latch_ex);
+  ut_ad(latch_readers--);
+  latch.rd_unlock();
+}
+#endif /* UNIV_PFS_RWLOCK */
+
+/**********************************************************************//**
+Returns a table object and increments its open handle count.
+NOTE! This is a high-level function to be used mainly from outside the
+'dict' directory. Inside this directory dict_table_get_low
+is usually the appropriate function.
+@param[in] table_name Table name
+@param[in] dict_locked whether dict_sys.latch is being held exclusively
+@param[in] ignore_err error to be ignored when loading the table
+@return table
+@retval nullptr if does not exist */
+dict_table_t*
+dict_table_open_on_name(
+	const char*		table_name,
+	bool			dict_locked,
+	dict_err_ignore_t	ignore_err)
+{
+  dict_table_t *table;
+  DBUG_ENTER("dict_table_open_on_name");
+  DBUG_PRINT("dict_table_open_on_name", ("table: '%s'", table_name));
+
+  const span<const char> name{table_name, strlen(table_name)};
+
+  if (!dict_locked)
+  {
+    dict_sys.freeze(SRW_LOCK_CALL);
+    table= dict_sys.find_table(name);
+    if (table)
+    {
+      ut_ad(table->cached);
+      if (!(ignore_err & ~DICT_ERR_IGNORE_FK_NOKEY) &&
+          !table->is_readable() && table->corrupted)
+      {
+        ulint algo = table->space->get_compression_algo();
+        if (algo <= PAGE_ALGORITHM_LAST && !fil_comp_algo_loaded(algo)) {
+	  my_printf_error(ER_PROVIDER_NOT_LOADED,
+            "Table %s is compressed with %s, which is not currently loaded. "
+            "Please load the %s provider plugin to open the table",
+	    MYF(ME_ERROR_LOG), table->name,
+            page_compression_algorithms[algo], page_compression_algorithms[algo]);
+        } else {
+	  my_printf_error(ER_TABLE_CORRUPT,
+            "Table %s is corrupted. Please drop the table and recreate.",
+	    MYF(ME_ERROR_LOG), table->name);
+	}
+        dict_sys.unfreeze();
+        DBUG_RETURN(nullptr);
+      }
+      table->acquire();
+      dict_sys.unfreeze();
+      DBUG_RETURN(table);
+    }
+    dict_sys.unfreeze();
+    dict_sys.lock(SRW_LOCK_CALL);
+  }
+
+  table= dict_sys.load_table(name, ignore_err);
+
+  if (table)
+  {
+    ut_ad(table->cached);
+    if (!(ignore_err & ~DICT_ERR_IGNORE_FK_NOKEY) &&
+        !table->is_readable() && table->corrupted)
+    {
+      ib::error() << "Table " << table->name
+                  << " is corrupted. Please drop the table and recreate.";
+      if (!dict_locked)
+        dict_sys.unlock();
+      DBUG_RETURN(nullptr);
+    }
+
+    table->acquire();
+  }
+
+  ut_ad(dict_lru_validate());
+  if (!dict_locked)
+    dict_sys.unlock();
+
+  DBUG_RETURN(table);
+}
+
+/**********************************************************************//**
+Adds system columns to a table object. */
+void
+dict_table_add_system_columns(
+/*==========================*/
+	dict_table_t*	table,	/*!< in/out: table */
+	mem_heap_t*	heap)	/*!< in: temporary heap */
+{
+	ut_ad(table->n_def == table->n_cols - DATA_N_SYS_COLS);
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(!table->cached);
+
+	/* NOTE: the system columns MUST be added in the following order
+	(so that they can be indexed by the numerical value of DATA_ROW_ID,
+	etc.) and as the last columns of the table memory object.
+	The clustered index will not always physically contain all system
+	columns. */
+
+	dict_mem_table_add_col(table, heap, "DB_ROW_ID", DATA_SYS,
+			       DATA_ROW_ID | DATA_NOT_NULL,
+			       DATA_ROW_ID_LEN);
+
+	compile_time_assert(DATA_ROW_ID == 0);
+	dict_mem_table_add_col(table, heap, "DB_TRX_ID", DATA_SYS,
+			       DATA_TRX_ID | DATA_NOT_NULL,
+			       DATA_TRX_ID_LEN);
+	compile_time_assert(DATA_TRX_ID == 1);
+	dict_mem_table_add_col(table, heap, "DB_ROLL_PTR", DATA_SYS,
+			       DATA_ROLL_PTR | DATA_NOT_NULL,
+			       DATA_ROLL_PTR_LEN);
+	compile_time_assert(DATA_ROLL_PTR == 2);
+
+	/* This check reminds that if a new system column is added to
+	the program, it should be dealt with here */
+	compile_time_assert(DATA_N_SYS_COLS == 3);
+}
+
+/** Add the table definition to the data dictionary cache */
+void dict_table_t::add_to_cache()
+{
+	cached = TRUE;
+
+	dict_sys.add(this);
+}
+
+/** Add a table definition to the data dictionary cache */
+inline void dict_sys_t::add(dict_table_t* table)
+{
+	ut_ad(!find(table));
+
+	ulint fold = my_crc32c(0, table->name.m_name,
+			       strlen(table->name.m_name));
+
+	table->autoinc_mutex.init();
+	table->lock_mutex_init();
+
+	/* Look for a table with the same name: error if such exists */
+	{
+		dict_table_t*	table2;
+		HASH_SEARCH(name_hash, &table_hash, fold,
+			    dict_table_t*, table2, ut_ad(table2->cached),
+			    !strcmp(table2->name.m_name, table->name.m_name));
+		ut_a(table2 == NULL);
+
+#ifdef UNIV_DEBUG
+		/* Look for the same table pointer with a different name */
+		HASH_SEARCH_ALL(name_hash, &table_hash,
+				dict_table_t*, table2, ut_ad(table2->cached),
+				table2 == table);
+		ut_ad(table2 == NULL);
+#endif /* UNIV_DEBUG */
+	}
+	HASH_INSERT(dict_table_t, name_hash, &table_hash, fold, table);
+
+	/* Look for a table with the same id: error if such exists */
+	hash_table_t* id_hash = table->is_temporary()
+		? &temp_id_hash : &table_id_hash;
+	const ulint id_fold = ut_fold_ull(table->id);
+	{
+		dict_table_t*	table2;
+		HASH_SEARCH(id_hash, id_hash, id_fold,
+			    dict_table_t*, table2, ut_ad(table2->cached),
+			    table2->id == table->id);
+		ut_a(table2 == NULL);
+
+#ifdef UNIV_DEBUG
+		/* Look for the same table pointer with a different id */
+		HASH_SEARCH_ALL(id_hash, id_hash,
+				dict_table_t*, table2, ut_ad(table2->cached),
+				table2 == table);
+		ut_ad(table2 == NULL);
+#endif /* UNIV_DEBUG */
+
+		HASH_INSERT(dict_table_t, id_hash, id_hash, id_fold, table);
+	}
+
+	UT_LIST_ADD_FIRST(table->can_be_evicted ? table_LRU : table_non_LRU,
+			  table);
+	ut_ad(dict_lru_validate());
+}
+
+/** Test whether a table can be evicted from dict_sys.table_LRU.
+@param table   table to be considered for eviction
+@return whether the table can be evicted */
+TRANSACTIONAL_TARGET
+static bool dict_table_can_be_evicted(dict_table_t *table)
+{
+	ut_ad(dict_sys.locked());
+	ut_a(table->can_be_evicted);
+	ut_a(table->foreign_set.empty());
+	ut_a(table->referenced_set.empty());
+
+	if (table->get_ref_count() == 0) {
+		/* The transaction commit and rollback are called from
+		outside the handler interface. This means that there is
+		a window where the table->n_ref_count can be zero but
+		the table instance is in "use". */
+
+		if (lock_table_has_locks(table)) {
+			return false;
+		}
+
+#ifdef BTR_CUR_HASH_ADAPT
+		/* We cannot really evict the table if adaptive hash
+		index entries are pointing to any of its indexes. */
+		for (const dict_index_t* index
+			     = dict_table_get_first_index(table);
+		     index; index = dict_table_get_next_index(index)) {
+			if (index->n_ahi_pages()) {
+				return false;
+			}
+		}
+#endif /* BTR_CUR_HASH_ADAPT */
+
+		ut_ad(!table->fts);
+		return true;
+	}
+
+	return false;
+}
+
+#ifdef BTR_CUR_HASH_ADAPT
+/** @return a clone of this */
+dict_index_t *dict_index_t::clone() const
+{
+  ut_ad(n_fields);
+  ut_ad(is_btree());
+  ut_ad(online_status == ONLINE_INDEX_COMPLETE);
+  ut_ad(is_committed());
+  ut_ad(!is_dummy);
+  ut_ad(!parser);
+  ut_ad(!online_log);
+  ut_ad(!rtr_track);
+
+  const size_t size= sizeof *this + n_fields * sizeof(*fields) +
+#ifdef BTR_CUR_ADAPT
+    sizeof *search_info +
+#endif
+    1 + strlen(name) +
+    n_uniq * (sizeof *stat_n_diff_key_vals +
+              sizeof *stat_n_sample_sizes +
+              sizeof *stat_n_non_null_key_vals);
+
+  mem_heap_t* heap= mem_heap_create(size);
+  dict_index_t *index= static_cast<dict_index_t*>
+    (mem_heap_alloc(heap, sizeof *this));
+  *index= *this;
+  index->lock.SRW_LOCK_INIT(index_tree_rw_lock_key);
+  index->heap= heap;
+  index->name= mem_heap_strdup(heap, name);
+  index->fields= static_cast<dict_field_t*>
+    (mem_heap_dup(heap, fields, n_fields * sizeof *fields));
+#ifdef BTR_CUR_ADAPT
+  index->search_info= btr_search_info_create(index->heap);
+#endif /* BTR_CUR_ADAPT */
+  index->stat_n_diff_key_vals= static_cast<ib_uint64_t*>
+    (mem_heap_zalloc(heap, n_uniq * sizeof *stat_n_diff_key_vals));
+  index->stat_n_sample_sizes= static_cast<ib_uint64_t*>
+    (mem_heap_zalloc(heap, n_uniq * sizeof *stat_n_sample_sizes));
+  index->stat_n_non_null_key_vals= static_cast<ib_uint64_t*>
+    (mem_heap_zalloc(heap, n_uniq * sizeof *stat_n_non_null_key_vals));
+  new (&index->zip_pad.mutex) std::mutex();
+  return index;
+}
+
+/** Clone this index for lazy dropping of the adaptive hash.
+@return this or a clone */
+dict_index_t *dict_index_t::clone_if_needed()
+{
+  if (!search_info->ref_count)
+    return this;
+  dict_index_t *prev= UT_LIST_GET_PREV(indexes, this);
+
+  table->autoinc_mutex.wr_lock();
+  UT_LIST_REMOVE(table->indexes, this);
+  UT_LIST_ADD_LAST(table->freed_indexes, this);
+  dict_index_t *index= clone();
+  set_freed();
+  if (prev)
+    UT_LIST_INSERT_AFTER(table->indexes, prev, index);
+  else
+    UT_LIST_ADD_FIRST(table->indexes, index);
+  table->autoinc_mutex.wr_unlock();
+  return index;
+}
+#endif /* BTR_CUR_HASH_ADAPT */
+
+/** Evict unused, unlocked tables from table_LRU.
+@param half whether to consider half the tables only (instead of all)
+@return number of tables evicted */
+ulint dict_sys_t::evict_table_LRU(bool half)
+{
+#ifdef MYSQL_DYNAMIC_PLUGIN
+	constexpr ulint max_tables = 400;
+#else
+	extern ulong tdc_size;
+	const ulint max_tables = tdc_size;
+#endif
+	ulint n_evicted = 0;
+
+	lock(SRW_LOCK_CALL);
+	ut_ad(dict_lru_validate());
+
+	const ulint len = UT_LIST_GET_LEN(table_LRU);
+
+	if (len < max_tables) {
+func_exit:
+		unlock();
+		return(n_evicted);
+	}
+
+	const ulint check_up_to = half ? len / 2 : 0;
+	ulint i = len;
+
+	/* Find a suitable candidate to evict from the cache. Don't scan the
+	entire LRU list. Only scan pct_check list entries. */
+
+	for (dict_table_t *table = UT_LIST_GET_LAST(table_LRU);
+	     table && i > check_up_to && (len - n_evicted) > max_tables; --i) {
+		dict_table_t* prev_table = UT_LIST_GET_PREV(table_LRU, table);
+
+		if (dict_table_can_be_evicted(table)) {
+			remove(table, true);
+			++n_evicted;
+		}
+
+		table = prev_table;
+	}
+
+	goto func_exit;
+}
+
+/** Looks for an index with the given id given a table instance.
+@param[in]	table	table instance
+@param[in]	id	index id
+@return index or NULL */
+dict_index_t*
+dict_table_find_index_on_id(
+	const dict_table_t*	table,
+	index_id_t		id)
+{
+	dict_index_t*	index;
+
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		if (id == index->id) {
+			/* Found */
+
+			return(index);
+		}
+	}
+
+	return(NULL);
+}
+
+/** Function object to remove a foreign key constraint from the
+referenced_set of the referenced table.  The foreign key object is
+also removed from the dictionary cache.  The foreign key constraint
+is not removed from the foreign_set of the table containing the
+constraint. */
+struct dict_foreign_remove_partial
+{
+	void operator()(dict_foreign_t* foreign) {
+		dict_table_t*	table = foreign->referenced_table;
+		if (table != NULL) {
+			table->referenced_set.erase(foreign);
+		}
+		dict_foreign_free(foreign);
+	}
+};
+
+/** This function returns a new path name after replacing the basename
+in an old path with a new basename.  The old_path is a full path
+name including the extension.  The tablename is in the normal
+form "databasename/tablename".  The new base name is found after
+the forward slash.  Both input strings are null terminated.
+
+This function allocates memory to be returned.  It is the callers
+responsibility to free the return value after it is no longer needed.
+
+@param[in]	old_path		Pathname
+@param[in]	tablename		Contains new base name
+@return own: new full pathname */
+static char *dir_pathname(const char *old_path, span<const char> tablename)
+{
+  /* Split the tablename into its database and table name components.
+  They are separated by a '/'. */
+  const char *base_name= tablename.data();
+  for (const char *last= tablename.end(); last > tablename.data(); last--)
+  {
+    if (last[-1] == '/')
+    {
+      base_name= last;
+      break;
+    }
+  }
+  const size_t base_name_len= tablename.end() - base_name;
+
+  /* Find the offset of the last slash. We will strip off the
+  old basename.ibd which starts after that slash. */
+  const char *last_slash= strrchr(old_path, '/');
+#ifdef _WIN32
+  if (const char *last= strrchr(old_path, '\\'))
+    if (last > last_slash)
+      last_slash= last;
+#endif
+
+  size_t dir_len= last_slash
+    ? size_t(last_slash - old_path)
+    : strlen(old_path);
+
+  /* allocate a new path and move the old directory path to it. */
+  size_t new_path_len= dir_len + base_name_len + sizeof "/.ibd";
+  char *new_path= static_cast<char*>(ut_malloc_nokey(new_path_len));
+  memcpy(new_path, old_path, dir_len);
+  snprintf(new_path + dir_len, new_path_len - dir_len, "/%.*s.ibd",
+           int(base_name_len), base_name);
+  return new_path;
+}
+
+/** Rename the data file.
+@param new_name     name of the table
+@param replace      whether to replace the file with the new name
+                    (as part of rolling back TRUNCATE) */
+dberr_t
+dict_table_t::rename_tablespace(span<const char> new_name, bool replace) const
+{
+  ut_ad(dict_table_is_file_per_table(this));
+  ut_ad(!is_temporary());
+
+  if (!space)
+    return DB_SUCCESS;
+
+  const char *old_path= UT_LIST_GET_FIRST(space->chain)->name;
+  const bool data_dir= DICT_TF_HAS_DATA_DIR(flags);
+  char *path= data_dir
+    ? dir_pathname(old_path, new_name)
+    : fil_make_filepath(nullptr, new_name, IBD, false);
+  dberr_t err;
+  if (!path)
+    err= DB_OUT_OF_MEMORY;
+  else if (!strcmp(path, old_path))
+    err= DB_SUCCESS;
+  else if (data_dir &&
+           DB_SUCCESS != RemoteDatafile::create_link_file(new_name, path))
+    err= DB_TABLESPACE_EXISTS;
+  else
+  {
+    space->x_lock();
+    err= space->rename(path, true, replace);
+    if (data_dir)
+    {
+      if (err == DB_SUCCESS)
+        new_name= {name.m_name, strlen(name.m_name)};
+      RemoteDatafile::delete_link_file(new_name);
+    }
+    space->x_unlock();
+  }
+
+  ut_free(path);
+  return err;
+}
+
+/**********************************************************************//**
+Renames a table object.
+@return TRUE if success */
+dberr_t
+dict_table_rename_in_cache(
+/*=======================*/
+	dict_table_t*	table,		/*!< in/out: table */
+	span<const char> new_name,	/*!< in: new name */
+	bool		replace_new_file)
+					/*!< in: whether to replace the
+					file with the new name
+					(as part of rolling back TRUNCATE) */
+{
+	dict_foreign_t*	foreign;
+	char		old_name[MAX_FULL_NAME_LEN + 1];
+
+	ut_ad(dict_sys.locked());
+
+	/* store the old/current name to an automatic variable */
+	const size_t old_name_len = strlen(table->name.m_name);
+	ut_a(old_name_len < sizeof old_name);
+	strcpy(old_name, table->name.m_name);
+
+	const uint32_t fold= my_crc32c(0, new_name.data(), new_name.size());
+	ut_a(!dict_sys.find_table(new_name));
+
+	if (!dict_table_is_file_per_table(table)) {
+	} else if (dberr_t err = table->rename_tablespace(new_name,
+							  replace_new_file)) {
+		return err;
+	}
+
+	/* Remove table from the hash tables of tables */
+	HASH_DELETE(dict_table_t, name_hash, &dict_sys.table_hash,
+		    my_crc32c(0, table->name.m_name, old_name_len), table);
+
+        bool keep_mdl_name = !table->name.is_temporary();
+
+	if (!keep_mdl_name) {
+	} else if (const char* s = static_cast<const char*>
+		   (memchr(new_name.data(), '/', new_name.size()))) {
+		keep_mdl_name = new_name.end() - s >= 5
+			&& !memcmp(s, "/#sql", 5);
+	}
+
+	if (keep_mdl_name) {
+		/* Preserve the original table name for
+		dict_table_t::parse_name() and dict_acquire_mdl_shared(). */
+		table->mdl_name.m_name = mem_heap_strdup(table->heap,
+							 table->name.m_name);
+	}
+
+	if (new_name.size() > strlen(table->name.m_name)) {
+		/* We allocate MAX_FULL_NAME_LEN + 1 bytes here to avoid
+		memory fragmentation, we assume a repeated calls of
+		ut_realloc() with the same size do not cause fragmentation */
+		ut_a(new_name.size() <= MAX_FULL_NAME_LEN);
+
+		table->name.m_name = static_cast<char*>(
+			ut_realloc(table->name.m_name, MAX_FULL_NAME_LEN + 1));
+	}
+	memcpy(table->name.m_name, new_name.data(), new_name.size());
+	table->name.m_name[new_name.size()] = '\0';
+
+	if (!keep_mdl_name) {
+		table->mdl_name.m_name = table->name.m_name;
+	}
+
+	/* Add table to hash table of tables */
+	HASH_INSERT(dict_table_t, name_hash, &dict_sys.table_hash, fold,
+		    table);
+
+	if (table->name.is_temporary()) {
+		/* In ALTER TABLE we think of the rename table operation
+		in the direction table -> temporary table (#sql...)
+		as dropping the table with the old name and creating
+		a new with the new name. Thus we kind of drop the
+		constraints from the dictionary cache here. The foreign key
+		constraints will be inherited to the new table from the
+		system tables through a call of dict_load_foreigns. */
+
+		/* Remove the foreign constraints from the cache */
+		std::for_each(table->foreign_set.begin(),
+			      table->foreign_set.end(),
+			      dict_foreign_remove_partial());
+		table->foreign_set.clear();
+
+		/* Reset table field in referencing constraints */
+		for (dict_foreign_set::iterator it
+			= table->referenced_set.begin();
+		     it != table->referenced_set.end();
+		     ++it) {
+
+			foreign = *it;
+			foreign->referenced_table = NULL;
+			foreign->referenced_index = NULL;
+
+		}
+
+		/* Make the set of referencing constraints empty */
+		table->referenced_set.clear();
+
+		return(DB_SUCCESS);
+	}
+
+	/* Update the table name fields in foreign constraints, and update also
+	the constraint id of new format >= 4.0.18 constraints. Note that at
+	this point we have already changed table->name to the new name. */
+
+	dict_foreign_set	fk_set;
+
+	for (;;) {
+
+		dict_foreign_set::iterator	it
+			= table->foreign_set.begin();
+
+		if (it == table->foreign_set.end()) {
+			break;
+		}
+
+		foreign = *it;
+
+		if (foreign->referenced_table) {
+			foreign->referenced_table->referenced_set.erase(foreign);
+		}
+
+		if (strlen(foreign->foreign_table_name)
+		    < strlen(table->name.m_name)) {
+			/* Allocate a longer name buffer;
+			TODO: store buf len to save memory */
+
+			foreign->foreign_table_name = mem_heap_strdup(
+				foreign->heap, table->name.m_name);
+			dict_mem_foreign_table_name_lookup_set(foreign, TRUE);
+		} else {
+			strcpy(foreign->foreign_table_name,
+			       table->name.m_name);
+			dict_mem_foreign_table_name_lookup_set(foreign, FALSE);
+		}
+		if (strchr(foreign->id, '/')) {
+			/* This is a >= 4.0.18 format id */
+
+			ulint	db_len;
+			char*	old_id;
+			char    old_name_cs_filename[MAX_FULL_NAME_LEN+1];
+			uint    errors = 0;
+
+			/* All table names are internally stored in charset
+			my_charset_filename (except the temp tables and the
+			partition identifier suffix in partition tables). The
+			foreign key constraint names are internally stored
+			in UTF-8 charset.  The variable fkid here is used
+			to store foreign key constraint name in charset
+			my_charset_filename for comparison further below. */
+			char    fkid[MAX_TABLE_NAME_LEN * 2 + 20];
+
+			/* The old table name in my_charset_filename is stored
+			in old_name_cs_filename */
+
+			strcpy(old_name_cs_filename, old_name);
+			old_name_cs_filename[MAX_FULL_NAME_LEN] = '\0';
+			if (!dict_table_t::is_temporary_name(old_name)) {
+				innobase_convert_to_system_charset(
+					strchr(old_name_cs_filename, '/') + 1,
+					strchr(old_name, '/') + 1,
+					MAX_TABLE_NAME_LEN, &errors);
+
+				if (errors) {
+					/* There has been an error to convert
+					old table into UTF-8.  This probably
+					means that the old table name is
+					actually in UTF-8. */
+					innobase_convert_to_filename_charset(
+						strchr(old_name_cs_filename,
+						       '/') + 1,
+						strchr(old_name, '/') + 1,
+						MAX_TABLE_NAME_LEN);
+				} else {
+					/* Old name already in
+					my_charset_filename */
+					strcpy(old_name_cs_filename, old_name);
+					old_name_cs_filename[MAX_FULL_NAME_LEN]
+						= '\0';
+				}
+			}
+
+			strncpy(fkid, foreign->id, (sizeof fkid) - 1);
+			fkid[(sizeof fkid) - 1] = '\0';
+
+			const bool on_tmp = dict_table_t::is_temporary_name(
+				fkid);
+
+			if (!on_tmp) {
+				innobase_convert_to_filename_charset(
+					strchr(fkid, '/') + 1,
+					strchr(foreign->id, '/') + 1,
+					MAX_TABLE_NAME_LEN+20);
+			}
+
+			old_id = mem_strdup(foreign->id);
+
+			if (strlen(fkid) > strlen(old_name_cs_filename)
+			    + ((sizeof dict_ibfk) - 1)
+			    && !memcmp(fkid, old_name_cs_filename,
+				       strlen(old_name_cs_filename))
+			    && !memcmp(fkid + strlen(old_name_cs_filename),
+				       dict_ibfk, (sizeof dict_ibfk) - 1)) {
+
+				/* This is a generated >= 4.0.18 format id */
+
+				char	table_name[MAX_TABLE_NAME_LEN + 1];
+				uint	errors = 0;
+
+				if (strlen(table->name.m_name)
+				    > strlen(old_name)) {
+					foreign->id = static_cast<char*>(
+						mem_heap_alloc(
+						foreign->heap,
+						strlen(table->name.m_name)
+						+ strlen(old_id) + 1));
+				}
+
+				/* Convert the table name to UTF-8 */
+				strncpy(table_name, table->name.m_name,
+					MAX_TABLE_NAME_LEN);
+				table_name[MAX_TABLE_NAME_LEN] = '\0';
+				innobase_convert_to_system_charset(
+					strchr(table_name, '/') + 1,
+					strchr(table->name.m_name, '/') + 1,
+					MAX_TABLE_NAME_LEN, &errors);
+
+				if (errors) {
+					/* Table name could not be converted
+					from charset my_charset_filename to
+					UTF-8. This means that the table name
+					is already in UTF-8 (#mysql50#). */
+					strncpy(table_name, table->name.m_name,
+						MAX_TABLE_NAME_LEN);
+					table_name[MAX_TABLE_NAME_LEN] = '\0';
+				}
+
+				/* Replace the prefix 'databasename/tablename'
+				with the new names */
+				strcpy(foreign->id, table_name);
+				if (on_tmp) {
+					strcat(foreign->id,
+					       old_id + strlen(old_name));
+				} else {
+					sprintf(strchr(foreign->id, '/') + 1,
+						"%s%s",
+						strchr(table_name, '/') +1,
+						strstr(old_id, "_ibfk_") );
+				}
+
+			} else {
+				/* This is a >= 4.0.18 format id where the user
+				gave the id name */
+				db_len = dict_get_db_name_len(
+					table->name.m_name) + 1;
+
+				if (db_len - 1
+				    > dict_get_db_name_len(foreign->id)) {
+
+					foreign->id = static_cast<char*>(
+						mem_heap_alloc(
+						foreign->heap,
+						db_len + strlen(old_id) + 1));
+				}
+
+				/* Replace the database prefix in id with the
+				one from table->name */
+
+				memcpy(foreign->id,
+				       table->name.m_name, db_len);
+
+				strcpy(foreign->id + db_len,
+				       dict_remove_db_name(old_id));
+			}
+
+			ut_free(old_id);
+		}
+
+		table->foreign_set.erase(it);
+		fk_set.insert(foreign);
+
+		if (foreign->referenced_table) {
+			foreign->referenced_table->referenced_set.insert(foreign);
+		}
+	}
+
+	ut_a(table->foreign_set.empty());
+	table->foreign_set.swap(fk_set);
+
+	for (dict_foreign_set::iterator it = table->referenced_set.begin();
+	     it != table->referenced_set.end();
+	     ++it) {
+
+		foreign = *it;
+
+		if (strlen(foreign->referenced_table_name)
+		    < strlen(table->name.m_name)) {
+			/* Allocate a longer name buffer;
+			TODO: store buf len to save memory */
+
+			foreign->referenced_table_name = mem_heap_strdup(
+				foreign->heap, table->name.m_name);
+
+			dict_mem_referenced_table_name_lookup_set(
+				foreign, TRUE);
+		} else {
+			/* Use the same buffer */
+			strcpy(foreign->referenced_table_name,
+			       table->name.m_name);
+
+			dict_mem_referenced_table_name_lookup_set(
+				foreign, FALSE);
+		}
+	}
+
+	return(DB_SUCCESS);
+}
+
+/**********************************************************************//**
+Change the id of a table object in the dictionary cache. This is used in
+DISCARD TABLESPACE. */
+void
+dict_table_change_id_in_cache(
+/*==========================*/
+	dict_table_t*	table,	/*!< in/out: table object already in cache */
+	table_id_t	new_id)	/*!< in: new id to set */
+{
+	ut_ad(dict_sys.locked());
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(!table->is_temporary());
+
+	/* Remove the table from the hash table of id's */
+
+	HASH_DELETE(dict_table_t, id_hash, &dict_sys.table_id_hash,
+		    ut_fold_ull(table->id), table);
+	table->id = new_id;
+
+	/* Add the table back to the hash table */
+	HASH_INSERT(dict_table_t, id_hash, &dict_sys.table_id_hash,
+		    ut_fold_ull(table->id), table);
+}
+
+/** Evict a table definition from the InnoDB data dictionary cache.
+@param[in,out]	table	cached table definition to be evicted
+@param[in]	lru	whether this is part of least-recently-used eviction
+@param[in]	keep	whether to keep (not free) the object */
+void dict_sys_t::remove(dict_table_t* table, bool lru, bool keep)
+{
+	dict_foreign_t*	foreign;
+	dict_index_t*	index;
+
+	ut_ad(dict_lru_validate());
+	ut_a(table->get_ref_count() == 0);
+	ut_a(table->n_rec_locks == 0);
+	ut_ad(find(table));
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+
+	/* Remove the foreign constraints from the cache */
+	std::for_each(table->foreign_set.begin(), table->foreign_set.end(),
+		      dict_foreign_remove_partial());
+	table->foreign_set.clear();
+
+	/* Reset table field in referencing constraints */
+	for (dict_foreign_set::iterator it = table->referenced_set.begin();
+	     it != table->referenced_set.end();
+	     ++it) {
+
+		foreign = *it;
+		foreign->referenced_table = NULL;
+		foreign->referenced_index = NULL;
+	}
+
+	/* Remove the indexes from the cache */
+
+	for (index = UT_LIST_GET_LAST(table->indexes);
+	     index != NULL;
+	     index = UT_LIST_GET_LAST(table->indexes)) {
+
+		dict_index_remove_from_cache_low(table, index, lru);
+	}
+
+	/* Remove table from the hash tables of tables */
+
+	HASH_DELETE(dict_table_t, name_hash, &table_hash,
+		    my_crc32c(0, table->name.m_name,
+			      strlen(table->name.m_name)),
+		    table);
+
+	hash_table_t* id_hash = table->is_temporary()
+		? &temp_id_hash : &table_id_hash;
+	const ulint id_fold = ut_fold_ull(table->id);
+	HASH_DELETE(dict_table_t, id_hash, id_hash, id_fold, table);
+
+	/* Remove table from LRU or non-LRU list. */
+	if (table->can_be_evicted) {
+		UT_LIST_REMOVE(table_LRU, table);
+	} else {
+		UT_LIST_REMOVE(table_non_LRU, table);
+	}
+
+	/* Free virtual column template if any */
+	if (table->vc_templ != NULL) {
+		dict_free_vc_templ(table->vc_templ);
+		UT_DELETE(table->vc_templ);
+	}
+
+	table->lock_mutex_destroy();
+
+	if (keep) {
+		table->autoinc_mutex.destroy();
+		return;
+	}
+
+#ifdef BTR_CUR_HASH_ADAPT
+	if (table->fts) {
+		fts_optimize_remove_table(table);
+		table->fts->~fts_t();
+		table->fts = nullptr;
+	}
+
+	table->autoinc_mutex.wr_lock();
+
+	ulint freed = UT_LIST_GET_LEN(table->freed_indexes);
+
+	table->vc_templ = NULL;
+	table->id = 0;
+	table->autoinc_mutex.wr_unlock();
+
+	if (UNIV_UNLIKELY(freed != 0)) {
+		return;
+	}
+#endif /* BTR_CUR_HASH_ADAPT */
+
+	table->autoinc_mutex.destroy();
+	dict_mem_table_free(table);
+}
+
+/****************************************************************//**
+If the given column name is reserved for InnoDB system columns, return
+TRUE.
+@return TRUE if name is reserved */
+ibool
+dict_col_name_is_reserved(
+/*======================*/
+	const char*	name)	/*!< in: column name */
+{
+	static const char*	reserved_names[] = {
+		"DB_ROW_ID", "DB_TRX_ID", "DB_ROLL_PTR"
+	};
+
+	compile_time_assert(UT_ARR_SIZE(reserved_names) == DATA_N_SYS_COLS);
+
+	for (ulint i = 0; i < UT_ARR_SIZE(reserved_names); i++) {
+		if (innobase_strcasecmp(name, reserved_names[i]) == 0) {
+
+			return(TRUE);
+		}
+	}
+
+	return(FALSE);
+}
+
+/** Adds an index to the dictionary cache, with possible indexing newly
+added column.
+@param[in,out]	index	index; NOTE! The index memory
+			object is freed in this function!
+@param[in]	page_no	root page number of the index
+@param[in]	add_v	virtual columns being added along with ADD INDEX
+@return DB_SUCCESS, or DB_CORRUPTION */
+dberr_t
+dict_index_add_to_cache(
+	dict_index_t*&		index,
+	ulint			page_no,
+	const dict_add_v_col_t* add_v)
+{
+	dict_index_t*	new_index;
+	ulint		n_ord;
+	ulint		i;
+
+	ut_ad(dict_sys.locked());
+	ut_ad(index->n_def == index->n_fields);
+	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
+	ut_ad(!dict_index_is_online_ddl(index));
+	ut_ad(!dict_index_is_ibuf(index));
+
+	ut_d(mem_heap_validate(index->heap));
+	ut_a(!dict_index_is_clust(index)
+	     || UT_LIST_GET_LEN(index->table->indexes) == 0);
+	ut_ad(dict_index_is_clust(index) || !index->table->no_rollback());
+
+	if (!dict_index_find_cols(index, add_v)) {
+
+		dict_mem_index_free(index);
+		index = NULL;
+		return DB_CORRUPTION;
+	}
+
+	/* Build the cache internal representation of the index,
+	containing also the added system fields */
+
+	if (dict_index_is_clust(index)) {
+		new_index = dict_index_build_internal_clust(index);
+	} else {
+		new_index = (index->type & DICT_FTS)
+			? dict_index_build_internal_fts(index)
+			: dict_index_build_internal_non_clust(index);
+		new_index->n_core_null_bytes = static_cast<uint8_t>(
+			UT_BITS_IN_BYTES(unsigned(new_index->n_nullable)));
+	}
+
+	/* Set the n_fields value in new_index to the actual defined
+	number of fields in the cache internal representation */
+
+	new_index->n_fields = new_index->n_def;
+	new_index->trx_id = index->trx_id;
+	new_index->set_committed(index->is_committed());
+	new_index->nulls_equal = index->nulls_equal;
+
+	n_ord = new_index->n_uniq;
+	/* Flag the ordering columns and also set column max_prefix */
+
+	for (i = 0; i < n_ord; i++) {
+		const dict_field_t*	field
+			= dict_index_get_nth_field(new_index, i);
+
+		/* Check the column being added in the index for
+		the first time and flag the ordering column. */
+		if (field->col->ord_part == 0 ) {
+			field->col->max_prefix = field->prefix_len;
+			field->col->ord_part = 1;
+		} else if (field->prefix_len == 0) {
+			/* Set the max_prefix for a column to 0 if
+			its prefix length is 0 (for this index)
+			even if it was a part of any other index
+			with some prefix length. */
+			field->col->max_prefix = 0;
+		} else if (field->col->max_prefix != 0
+			   && field->prefix_len
+			   > field->col->max_prefix) {
+			/* Set the max_prefix value based on the
+			prefix_len. */
+			ut_ad(field->col->is_binary()
+			      || field->prefix_len % field->col->mbmaxlen == 0
+			      || field->prefix_len % 4 == 0);
+			field->col->max_prefix = field->prefix_len;
+		}
+		ut_ad(field->col->ord_part == 1);
+	}
+
+	new_index->stat_n_diff_key_vals =
+		static_cast<ib_uint64_t*>(mem_heap_zalloc(
+			new_index->heap,
+			dict_index_get_n_unique(new_index)
+			* sizeof(*new_index->stat_n_diff_key_vals)));
+
+	new_index->stat_n_sample_sizes =
+		static_cast<ib_uint64_t*>(mem_heap_zalloc(
+			new_index->heap,
+			dict_index_get_n_unique(new_index)
+			* sizeof(*new_index->stat_n_sample_sizes)));
+
+	new_index->stat_n_non_null_key_vals =
+		static_cast<ib_uint64_t*>(mem_heap_zalloc(
+			new_index->heap,
+			dict_index_get_n_unique(new_index)
+			* sizeof(*new_index->stat_n_non_null_key_vals)));
+
+	new_index->stat_index_size = 1;
+	new_index->stat_n_leaf_pages = 1;
+
+	new_index->stat_defrag_n_pages_freed = 0;
+	new_index->stat_defrag_n_page_split = 0;
+
+	new_index->stat_defrag_sample_next_slot = 0;
+	memset(&new_index->stat_defrag_data_size_sample,
+	       0x0, sizeof(ulint) * STAT_DEFRAG_DATA_SIZE_N_SAMPLE);
+
+	/* Add the new index as the last index for the table */
+
+	UT_LIST_ADD_LAST(new_index->table->indexes, new_index);
+#ifdef BTR_CUR_ADAPT
+	new_index->search_info = btr_search_info_create(new_index->heap);
+#endif /* BTR_CUR_ADAPT */
+
+	new_index->page = unsigned(page_no);
+	new_index->lock.SRW_LOCK_INIT(index_tree_rw_lock_key);
+
+	new_index->n_core_fields = new_index->n_fields;
+
+	dict_mem_index_free(index);
+	index = new_index;
+	return DB_SUCCESS;
+}
+
+/**********************************************************************//**
+Removes an index from the dictionary cache. */
+TRANSACTIONAL_TARGET
+static
+void
+dict_index_remove_from_cache_low(
+/*=============================*/
+	dict_table_t*	table,		/*!< in/out: table */
+	dict_index_t*	index,		/*!< in, own: index */
+	ibool		lru_evict)	/*!< in: TRUE if index being evicted
+					to make room in the table LRU list */
+{
+	ut_ad(table && index);
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
+	ut_ad(dict_sys.locked());
+	ut_ad(table->id);
+#ifdef BTR_CUR_HASH_ADAPT
+	ut_ad(!index->freed());
+#endif /* BTR_CUR_HASH_ADAPT */
+
+	/* No need to acquire the dict_index_t::lock here because
+	there can't be any active operations on this index (or table). */
+
+	if (index->online_log) {
+		row_log_free(index->online_log);
+		index->online_log = NULL;
+	}
+
+	/* Remove the index from the list of indexes of the table */
+	UT_LIST_REMOVE(table->indexes, index);
+
+	/* The index is being dropped, remove any compression stats for it. */
+	if (!lru_evict && DICT_TF_GET_ZIP_SSIZE(index->table->flags)) {
+		mysql_mutex_lock(&page_zip_stat_per_index_mutex);
+		page_zip_stat_per_index.erase(index->id);
+		mysql_mutex_unlock(&page_zip_stat_per_index_mutex);
+	}
+
+	/* Remove the index from affected virtual column index list */
+	index->detach_columns();
+
+#ifdef BTR_CUR_HASH_ADAPT
+	/* We always create search info whether or not adaptive
+	hash index is enabled or not. */
+	/* We are not allowed to free the in-memory index struct
+	dict_index_t until all entries in the adaptive hash index
+	that point to any of the page belonging to his b-tree index
+	are dropped. This is so because dropping of these entries
+	require access to dict_index_t struct. To avoid such scenario
+	We keep a count of number of such pages in the search_info and
+	only free the dict_index_t struct when this count drops to
+	zero. See also: dict_table_can_be_evicted() */
+
+	if (index->n_ahi_pages()) {
+		table->autoinc_mutex.wr_lock();
+		index->set_freed();
+		UT_LIST_ADD_LAST(table->freed_indexes, index);
+		table->autoinc_mutex.wr_unlock();
+		return;
+	}
+#endif /* BTR_CUR_HASH_ADAPT */
+
+	index->lock.free();
+
+	dict_mem_index_free(index);
+}
+
+/**********************************************************************//**
+Removes an index from the dictionary cache. */
+void
+dict_index_remove_from_cache(
+/*=========================*/
+	dict_table_t*	table,	/*!< in/out: table */
+	dict_index_t*	index)	/*!< in, own: index */
+{
+	dict_index_remove_from_cache_low(table, index, FALSE);
+}
+
+/** Tries to find column names for the index and sets the col field of the
+index.
+@param[in]	table	table
+@param[in,out]	index	index
+@param[in]	add_v	new virtual columns added along with an add index call
+@return whether the column names were found */
+static
+bool
+dict_index_find_cols(
+	dict_index_t*		index,
+	const dict_add_v_col_t*	add_v)
+{
+	std::vector<ulint, ut_allocator<ulint> >	col_added;
+	std::vector<ulint, ut_allocator<ulint> >	v_col_added;
+
+	const dict_table_t* table = index->table;
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(dict_sys.locked());
+
+	for (ulint i = 0; i < index->n_fields; i++) {
+		ulint		j;
+		dict_field_t*	field = dict_index_get_nth_field(index, i);
+
+		for (j = 0; j < table->n_cols; j++) {
+			if (!innobase_strcasecmp(dict_table_get_col_name(table, j),
+				    field->name)) {
+
+				/* Check if same column is being assigned again
+				which suggest that column has duplicate name. */
+				bool exists =
+					std::find(col_added.begin(),
+						  col_added.end(), j)
+					!= col_added.end();
+
+				if (exists) {
+					/* Duplicate column found. */
+					goto dup_err;
+				}
+
+				field->col = dict_table_get_nth_col(table, j);
+
+				col_added.push_back(j);
+
+				goto found;
+			}
+		}
+
+		/* Let's check if it is a virtual column */
+		for (j = 0; j < table->n_v_cols; j++) {
+			if (!strcmp(dict_table_get_v_col_name(table, j),
+				    field->name)) {
+
+				/* Check if same column is being assigned again
+				which suggest that column has duplicate name. */
+				bool exists =
+					std::find(v_col_added.begin(),
+						  v_col_added.end(), j)
+					!= v_col_added.end();
+
+				if (exists) {
+					/* Duplicate column found. */
+					break;
+				}
+
+				field->col = reinterpret_cast<dict_col_t*>(
+					dict_table_get_nth_v_col(table, j));
+
+				v_col_added.push_back(j);
+
+				goto found;
+			}
+		}
+
+		if (add_v) {
+			for (j = 0; j < add_v->n_v_col; j++) {
+				if (!strcmp(add_v->v_col_name[j],
+					    field->name)) {
+					field->col = const_cast<dict_col_t*>(
+						&add_v->v_col[j].m_col);
+					goto found;
+				}
+			}
+		}
+
+dup_err:
+#ifdef UNIV_DEBUG
+		/* It is an error not to find a matching column. */
+		ib::error() << "No matching column for " << field->name
+			<< " in index " << index->name
+			<< " of table " << table->name;
+#endif /* UNIV_DEBUG */
+		return(FALSE);
+
+found:
+		;
+	}
+
+	return(TRUE);
+}
+
+/** Add a column to an index.
+@param index          index
+@param table          table
+@param col            column
+@param prefix_len     column prefix length
+@param descending     whether to use descending order */
+void dict_index_add_col(dict_index_t *index, const dict_table_t *table,
+                        dict_col_t *col, ulint prefix_len, bool descending)
+{
+	dict_field_t*	field;
+	const char*	col_name;
+
+	if (col->is_virtual()) {
+		dict_v_col_t*	v_col = reinterpret_cast<dict_v_col_t*>(col);
+		/* Register the index with the virtual column index list */
+		v_col->v_indexes.push_front(dict_v_idx_t(index, index->n_def));
+		col_name = dict_table_get_v_col_name_mysql(
+			table, dict_col_get_no(col));
+	} else {
+		col_name = dict_table_get_col_name(table, dict_col_get_no(col));
+	}
+
+	dict_mem_index_add_field(index, col_name, prefix_len);
+
+	field = dict_index_get_nth_field(index, unsigned(index->n_def) - 1);
+
+	field->col = col;
+	field->fixed_len = static_cast<uint16_t>(
+		dict_col_get_fixed_size(
+			col, dict_table_is_comp(table)))
+		& ((1U << 10) - 1);
+
+	if (prefix_len && field->fixed_len > prefix_len) {
+		field->fixed_len = static_cast<uint16_t>(prefix_len)
+			& ((1U << 10) - 1);
+	}
+
+	/* Long fixed-length fields that need external storage are treated as
+	variable-length fields, so that the extern flag can be embedded in
+	the length word. */
+
+	if (field->fixed_len > DICT_MAX_FIXED_COL_LEN) {
+		field->fixed_len = 0;
+	}
+
+	field->descending = descending;
+
+	/* The comparison limit above must be constant.  If it were
+	changed, the disk format of some fixed-length columns would
+	change, which would be a disaster. */
+	compile_time_assert(DICT_MAX_FIXED_COL_LEN == 768);
+
+	if (!(col->prtype & DATA_NOT_NULL)) {
+		index->n_nullable++;
+	}
+}
+
+/*******************************************************************//**
+Copies fields contained in index2 to index1. */
+static
+void
+dict_index_copy(
+/*============*/
+	dict_index_t*		index1,	/*!< in: index to copy to */
+	const dict_index_t*	index2,	/*!< in: index to copy from */
+	ulint			start,	/*!< in: first position to copy */
+	ulint			end)	/*!< in: last position to copy */
+{
+	dict_field_t*	field;
+	ulint		i;
+
+	/* Copy fields contained in index2 */
+
+	for (i = start; i < end; i++) {
+
+		field = dict_index_get_nth_field(index2, i);
+
+		dict_index_add_col(index1, index2->table, field->col,
+				   field->prefix_len, field->descending);
+	}
+}
+
+/*******************************************************************//**
+Copies types of fields contained in index to tuple. */
+void
+dict_index_copy_types(
+/*==================*/
+	dtuple_t*		tuple,		/*!< in/out: data tuple */
+	const dict_index_t*	index,		/*!< in: index */
+	ulint			n_fields)	/*!< in: number of
+						field types to copy */
+{
+	ulint		i;
+
+	if (dict_index_is_ibuf(index)) {
+		dtuple_set_types_binary(tuple, n_fields);
+
+		return;
+	}
+
+	for (i = 0; i < n_fields; i++) {
+		const dict_field_t*	ifield;
+		dtype_t*		dfield_type;
+
+		ifield = dict_index_get_nth_field(index, i);
+		dfield_type = dfield_get_type(dtuple_get_nth_field(tuple, i));
+		dict_col_copy_type(dict_field_get_col(ifield), dfield_type);
+		if (dict_index_is_spatial(index)
+		    && DATA_GEOMETRY_MTYPE(dfield_type->mtype)) {
+			dfield_type->prtype |= DATA_GIS_MBR;
+		}
+	}
+}
+
+/** Copies types of virtual columns contained in table to tuple and sets all
+fields of the tuple to the SQL NULL value.  This function should
+be called right after dtuple_create().
+@param[in,out]	tuple	data tuple
+@param[in]	table	table
+*/
+void
+dict_table_copy_v_types(
+	dtuple_t*		tuple,
+	const dict_table_t*	table)
+{
+	/* tuple could have more virtual columns than existing table,
+	if we are calling this for creating index along with adding
+	virtual columns */
+	ulint	n_fields = ut_min(dtuple_get_n_v_fields(tuple),
+				  static_cast<ulint>(table->n_v_def));
+
+	for (ulint i = 0; i < n_fields; i++) {
+
+		dfield_t*	dfield	= dtuple_get_nth_v_field(tuple, i);
+		dtype_t*	dtype	= dfield_get_type(dfield);
+
+		dfield_set_null(dfield);
+		dict_col_copy_type(
+			&(dict_table_get_nth_v_col(table, i)->m_col),
+			dtype);
+	}
+}
+/*******************************************************************//**
+Copies types of columns contained in table to tuple and sets all
+fields of the tuple to the SQL NULL value.  This function should
+be called right after dtuple_create(). */
+void
+dict_table_copy_types(
+/*==================*/
+	dtuple_t*		tuple,	/*!< in/out: data tuple */
+	const dict_table_t*	table)	/*!< in: table */
+{
+	ulint		i;
+
+	for (i = 0; i < dtuple_get_n_fields(tuple); i++) {
+
+		dfield_t*	dfield	= dtuple_get_nth_field(tuple, i);
+		dtype_t*	dtype	= dfield_get_type(dfield);
+
+		dfield_set_null(dfield);
+		dict_col_copy_type(dict_table_get_nth_col(table, i), dtype);
+	}
+
+	dict_table_copy_v_types(tuple, table);
+}
+
+/*******************************************************************//**
+Builds the internal dictionary cache representation for a clustered
+index, containing also system fields not defined by the user.
+@return own: the internal representation of the clustered index */
+static
+dict_index_t*
+dict_index_build_internal_clust(
+/*============================*/
+	dict_index_t*		index)	/*!< in: user representation of
+					a clustered index */
+{
+	dict_table_t*	table = index->table;
+	dict_index_t*	new_index;
+	dict_field_t*	field;
+	ulint		trx_id_pos;
+	ulint		i;
+	ibool*		indexed;
+
+	ut_ad(index->is_primary());
+	ut_ad(!index->has_virtual());
+
+	ut_ad(dict_sys.locked());
+
+	/* Create a new index object with certainly enough fields */
+	new_index = dict_mem_index_create(index->table, index->name,
+					  index->type,
+					  unsigned(index->n_fields
+						   + table->n_cols));
+
+	/* Copy other relevant data from the old index struct to the new
+	struct: it inherits the values */
+
+	new_index->n_user_defined_cols = index->n_fields;
+
+	new_index->id = index->id;
+
+	/* Copy the fields of index */
+	dict_index_copy(new_index, index, 0, index->n_fields);
+
+	if (dict_index_is_unique(index)) {
+		/* Only the fields defined so far are needed to identify
+		the index entry uniquely */
+
+		new_index->n_uniq = new_index->n_def;
+	} else {
+		/* Also the row id is needed to identify the entry */
+		new_index->n_uniq = unsigned(new_index->n_def + 1)
+			& dict_index_t::MAX_N_FIELDS;
+	}
+
+	new_index->trx_id_offset = 0;
+
+	/* Add system columns, trx id first */
+
+	trx_id_pos = new_index->n_def;
+
+	compile_time_assert(DATA_ROW_ID == 0);
+	compile_time_assert(DATA_TRX_ID == 1);
+	compile_time_assert(DATA_ROLL_PTR == 2);
+
+	if (!dict_index_is_unique(index)) {
+		dict_index_add_col(new_index, table,
+				   dict_table_get_sys_col(
+					   table, DATA_ROW_ID),
+				   0);
+		trx_id_pos++;
+	}
+
+	dict_index_add_col(
+		new_index, table,
+		dict_table_get_sys_col(table, DATA_TRX_ID), 0);
+
+	for (i = 0; i < trx_id_pos; i++) {
+
+		ulint	fixed_size = dict_col_get_fixed_size(
+			dict_index_get_nth_col(new_index, i),
+			dict_table_is_comp(table));
+
+		if (fixed_size == 0) {
+			new_index->trx_id_offset = 0;
+
+			break;
+		}
+
+		dict_field_t* field = dict_index_get_nth_field(
+			new_index, i);
+		if (field->prefix_len > 0) {
+			new_index->trx_id_offset = 0;
+
+			break;
+		}
+
+		/* Add fixed_size to new_index->trx_id_offset.
+		Because the latter is a bit-field, an overflow
+		can theoretically occur. Check for it. */
+		fixed_size += new_index->trx_id_offset;
+
+		new_index->trx_id_offset = static_cast<unsigned>(fixed_size)
+			& ((1U << 12) - 1);
+
+		if (new_index->trx_id_offset != fixed_size) {
+			/* Overflow. Pretend that this is a
+			variable-length PRIMARY KEY. */
+			ut_ad(0);
+			new_index->trx_id_offset = 0;
+			break;
+		}
+	}
+
+	dict_index_add_col(
+		new_index, table,
+		dict_table_get_sys_col(table, DATA_ROLL_PTR), 0);
+
+	/* Remember the table columns already contained in new_index */
+	indexed = static_cast<ibool*>(
+		ut_zalloc_nokey(table->n_cols * sizeof *indexed));
+
+	/* Mark the table columns already contained in new_index */
+	for (i = 0; i < new_index->n_def; i++) {
+
+		field = dict_index_get_nth_field(new_index, i);
+
+		/* If there is only a prefix of the column in the index
+		field, do not mark the column as contained in the index */
+
+		if (field->prefix_len == 0) {
+
+			indexed[field->col->ind] = TRUE;
+		}
+	}
+
+	/* Add to new_index non-system columns of table not yet included
+	there */
+	for (i = 0; i + DATA_N_SYS_COLS < ulint(table->n_cols); i++) {
+		dict_col_t*	col = dict_table_get_nth_col(table, i);
+		ut_ad(col->mtype != DATA_SYS);
+
+		if (!indexed[col->ind]) {
+			dict_index_add_col(new_index, table, col, 0);
+		}
+	}
+
+	ut_free(indexed);
+
+	ut_ad(UT_LIST_GET_LEN(table->indexes) == 0);
+
+	new_index->n_core_null_bytes = table->supports_instant()
+		? dict_index_t::NO_CORE_NULL_BYTES
+		: static_cast<uint8_t>(
+			UT_BITS_IN_BYTES(unsigned(new_index->n_nullable)));
+	new_index->cached = TRUE;
+
+	return(new_index);
+}
+
+/*******************************************************************//**
+Builds the internal dictionary cache representation for a non-clustered
+index, containing also system fields not defined by the user.
+@return own: the internal representation of the non-clustered index */
+static
+dict_index_t*
+dict_index_build_internal_non_clust(
+/*================================*/
+	dict_index_t*		index)	/*!< in: user representation of
+					a non-clustered index */
+{
+	dict_field_t*	field;
+	dict_index_t*	new_index;
+	dict_index_t*	clust_index;
+	dict_table_t*	table = index->table;
+	ulint		i;
+	ibool*		indexed;
+
+	ut_ad(table && index);
+	ut_ad(!dict_index_is_clust(index));
+	ut_ad(!dict_index_is_ibuf(index));
+	ut_ad(dict_sys.locked());
+
+	/* The clustered index should be the first in the list of indexes */
+	clust_index = UT_LIST_GET_FIRST(table->indexes);
+
+	ut_ad(clust_index);
+	ut_ad(dict_index_is_clust(clust_index));
+	ut_ad(!dict_index_is_ibuf(clust_index));
+
+	/* Create a new index */
+	new_index = dict_mem_index_create(
+		index->table, index->name, index->type,
+		ulint(index->n_fields + 1 + clust_index->n_uniq));
+
+	/* Copy other relevant data from the old index
+	struct to the new struct: it inherits the values */
+
+	new_index->n_user_defined_cols = index->n_fields;
+
+	new_index->id = index->id;
+
+	/* Copy fields from index to new_index */
+	dict_index_copy(new_index, index, 0, index->n_fields);
+
+	/* Remember the table columns already contained in new_index */
+	indexed = static_cast<ibool*>(
+		ut_zalloc_nokey(table->n_cols * sizeof *indexed));
+
+	/* Mark the table columns already contained in new_index */
+	for (i = 0; i < new_index->n_def; i++) {
+
+		field = dict_index_get_nth_field(new_index, i);
+
+		if (field->col->is_virtual()) {
+			continue;
+		}
+
+		/* If there is only a prefix of the column in the index
+		field, do not mark the column as contained in the index */
+
+		if (field->prefix_len == 0) {
+
+			indexed[field->col->ind] = TRUE;
+		}
+	}
+
+	/* Add to new_index the columns necessary to determine the clustered
+	index entry uniquely */
+
+	for (i = 0; i < clust_index->n_uniq; i++) {
+		field = dict_index_get_nth_field(clust_index, i);
+
+		if (!indexed[field->col->ind] || index->is_spatial()) {
+			dict_index_add_col(new_index, table, field->col,
+					   field->prefix_len,
+					   field->descending);
+		}
+	}
+
+	ut_free(indexed);
+
+	if (dict_index_is_unique(index)) {
+		new_index->n_uniq = index->n_fields;
+	} else {
+		new_index->n_uniq = new_index->n_def;
+	}
+
+	/* Set the n_fields value in new_index to the actual defined
+	number of fields */
+
+	new_index->n_fields = new_index->n_def;
+
+	new_index->cached = TRUE;
+
+	return(new_index);
+}
+
+/***********************************************************************
+Builds the internal dictionary cache representation for an FTS index.
+@return own: the internal representation of the FTS index */
+static
+dict_index_t*
+dict_index_build_internal_fts(
+/*==========================*/
+	dict_index_t*	index)	/*!< in: user representation of an FTS index */
+{
+	dict_index_t*	new_index;
+
+	ut_ad(index->type & DICT_FTS);
+	ut_ad(dict_sys.locked());
+
+	/* Create a new index */
+	new_index = dict_mem_index_create(index->table, index->name,
+					  index->type, index->n_fields);
+
+	/* Copy other relevant data from the old index struct to the new
+	struct: it inherits the values */
+
+	new_index->n_user_defined_cols = index->n_fields;
+
+	new_index->id = index->id;
+
+	/* Copy fields from index to new_index */
+	dict_index_copy(new_index, index, 0, index->n_fields);
+
+	new_index->n_uniq = 0;
+	new_index->cached = TRUE;
+
+	dict_table_t* table = index->table;
+
+	if (table->fts->cache == NULL) {
+		table->fts->cache = fts_cache_create(table);
+	}
+
+	mysql_mutex_lock(&table->fts->cache->init_lock);
+	/* Notify the FTS cache about this index. */
+	fts_cache_index_cache_create(table, new_index);
+	mysql_mutex_unlock(&table->fts->cache->init_lock);
+
+	return(new_index);
+}
+/*====================== FOREIGN KEY PROCESSING ========================*/
+
+/**********************************************************************//**
+Removes a foreign constraint struct from the dictionary cache. */
+void
+dict_foreign_remove_from_cache(
+/*===========================*/
+	dict_foreign_t*	foreign)	/*!< in, own: foreign constraint */
+{
+	ut_ad(dict_sys.locked());
+	ut_a(foreign);
+
+	if (foreign->referenced_table != NULL) {
+		foreign->referenced_table->referenced_set.erase(foreign);
+	}
+
+	if (foreign->foreign_table != NULL) {
+		foreign->foreign_table->foreign_set.erase(foreign);
+	}
+
+	dict_foreign_free(foreign);
+}
+
+/**********************************************************************//**
+Looks for the foreign constraint from the foreign and referenced lists
+of a table.
+@return foreign constraint */
+static
+dict_foreign_t*
+dict_foreign_find(
+/*==============*/
+	dict_table_t*	table,		/*!< in: table object */
+	dict_foreign_t*	foreign)	/*!< in: foreign constraint */
+{
+	ut_ad(dict_sys.frozen());
+
+	ut_ad(dict_foreign_set_validate(table->foreign_set));
+	ut_ad(dict_foreign_set_validate(table->referenced_set));
+
+	dict_foreign_set::iterator it = table->foreign_set.find(foreign);
+
+	if (it != table->foreign_set.end()) {
+		return(*it);
+	}
+
+	it = table->referenced_set.find(foreign);
+
+	if (it != table->referenced_set.end()) {
+		return(*it);
+	}
+
+	return(NULL);
+}
+
+/*********************************************************************//**
+Tries to find an index whose first fields are the columns in the array,
+in the same order and is not marked for deletion and is not the same
+as types_idx.
+@return matching index, NULL if not found */
+dict_index_t*
+dict_foreign_find_index(
+/*====================*/
+	const dict_table_t*	table,	/*!< in: table */
+	const char**		col_names,
+					/*!< in: column names, or NULL
+					to use table->col_names */
+	const char**		columns,/*!< in: array of column names */
+	ulint			n_cols,	/*!< in: number of columns */
+	const dict_index_t*	types_idx,
+					/*!< in: NULL or an index
+					whose types the column types
+					must match */
+	bool			check_charsets,
+					/*!< in: whether to check
+					charsets.  only has an effect
+					if types_idx != NULL */
+	ulint			check_null,
+					/*!< in: nonzero if none of
+					the columns must be declared
+					NOT NULL */
+	fkerr_t*		error,	/*!< out: error code */
+	ulint*			err_col_no,
+					/*!< out: column number where
+					error happened */
+	dict_index_t**		err_index)
+					/*!< out: index where error
+					happened */
+{
+	ut_ad(dict_sys.frozen());
+
+	if (error) {
+		*error = FK_INDEX_NOT_FOUND;
+	}
+
+	for (dict_index_t* index = dict_table_get_first_index(table);
+	     index;
+	     index = dict_table_get_next_index(index)) {
+		if (types_idx != index
+		    && !index->to_be_dropped
+		    && !dict_index_is_online_ddl(index)
+		    && dict_foreign_qualify_index(
+			    table, col_names, columns, n_cols,
+			    index, types_idx,
+			    check_charsets, check_null,
+			    error, err_col_no, err_index)) {
+			if (error) {
+				*error = FK_SUCCESS;
+			}
+
+			return(index);
+		}
+	}
+
+	return(NULL);
+}
+/**********************************************************************//**
+Report an error in a foreign key definition. */
+static
+void
+dict_foreign_error_report_low(
+/*==========================*/
+	FILE*		file,	/*!< in: output stream */
+	const char*	name)	/*!< in: table name */
+{
+	rewind(file);
+	ut_print_timestamp(file);
+	fprintf(file, " Error in foreign key constraint of table %s:\n",
+		name);
+}
+
+/**********************************************************************//**
+Report an error in a foreign key definition. */
+static
+void
+dict_foreign_error_report(
+/*======================*/
+	FILE*		file,	/*!< in: output stream */
+	dict_foreign_t*	fk,	/*!< in: foreign key constraint */
+	const char*	msg)	/*!< in: the error message */
+{
+	std::string fk_str;
+	mysql_mutex_lock(&dict_foreign_err_mutex);
+	dict_foreign_error_report_low(file, fk->foreign_table_name);
+	fputs(msg, file);
+	fputs(" Constraint:\n", file);
+	fk_str = dict_print_info_on_foreign_key_in_create_format(NULL, fk, TRUE);
+	fputs(fk_str.c_str(), file);
+	putc('\n', file);
+	if (fk->foreign_index) {
+		fprintf(file, "The index in the foreign key in table is"
+			" %s\n%s\n", fk->foreign_index->name(),
+			FOREIGN_KEY_CONSTRAINTS_MSG);
+	}
+	mysql_mutex_unlock(&dict_foreign_err_mutex);
+}
+
+/**********************************************************************//**
+Adds a foreign key constraint object to the dictionary cache. May free
+the object if there already is an object with the same identifier in.
+At least one of the foreign table and the referenced table must already
+be in the dictionary cache!
+@return DB_SUCCESS or error code */
+dberr_t
+dict_foreign_add_to_cache(
+/*======================*/
+	dict_foreign_t*		foreign,
+				/*!< in, own: foreign key constraint */
+	const char**		col_names,
+				/*!< in: column names, or NULL to use
+				foreign->foreign_table->col_names */
+	bool			check_charsets,
+				/*!< in: whether to check charset
+				compatibility */
+	dict_err_ignore_t	ignore_err)
+				/*!< in: error to be ignored */
+{
+	dict_table_t*	for_table;
+	dict_table_t*	ref_table;
+	dict_foreign_t*	for_in_cache		= NULL;
+	dict_index_t*	index;
+	ibool		added_to_referenced_list= FALSE;
+	FILE*		ef			= dict_foreign_err_file;
+
+	DBUG_ENTER("dict_foreign_add_to_cache");
+	DBUG_PRINT("dict_foreign_add_to_cache", ("id: %s", foreign->id));
+
+	ut_ad(dict_sys.locked());
+
+	for_table = dict_sys.find_table(
+		{foreign->foreign_table_name_lookup,
+		 strlen(foreign->foreign_table_name_lookup)});
+
+	ref_table = dict_sys.find_table(
+		{foreign->referenced_table_name_lookup,
+		 strlen(foreign->referenced_table_name_lookup)});
+	ut_a(for_table || ref_table);
+
+	if (for_table) {
+		for_in_cache = dict_foreign_find(for_table, foreign);
+	}
+
+	if (!for_in_cache && ref_table) {
+		for_in_cache = dict_foreign_find(ref_table, foreign);
+	}
+
+	if (for_in_cache) {
+		dict_foreign_free(foreign);
+	} else {
+		for_in_cache = foreign;
+
+	}
+
+	if (ref_table && !for_in_cache->referenced_table) {
+		index = dict_foreign_find_index(
+			ref_table, NULL,
+			for_in_cache->referenced_col_names,
+			for_in_cache->n_fields, for_in_cache->foreign_index,
+			check_charsets, false);
+
+		if (index == NULL
+		    && !(ignore_err & DICT_ERR_IGNORE_FK_NOKEY)) {
+			dict_foreign_error_report(
+				ef, for_in_cache,
+				"there is no index in referenced table"
+				" which would contain\n"
+				"the columns as the first columns,"
+				" or the data types in the\n"
+				"referenced table do not match"
+				" the ones in table.");
+
+			if (for_in_cache == foreign) {
+				dict_foreign_free(foreign);
+			}
+
+			DBUG_RETURN(DB_CANNOT_ADD_CONSTRAINT);
+		}
+
+		for_in_cache->referenced_table = ref_table;
+		for_in_cache->referenced_index = index;
+
+		std::pair<dict_foreign_set::iterator, bool>	ret
+			= ref_table->referenced_set.insert(for_in_cache);
+
+		ut_a(ret.second);	/* second is true if the insertion
+					took place */
+		added_to_referenced_list = TRUE;
+	}
+
+	if (for_table && !for_in_cache->foreign_table) {
+		index = dict_foreign_find_index(
+			for_table, col_names,
+			for_in_cache->foreign_col_names,
+			for_in_cache->n_fields,
+			for_in_cache->referenced_index, check_charsets,
+			for_in_cache->type
+			& (DICT_FOREIGN_ON_DELETE_SET_NULL
+			   | DICT_FOREIGN_ON_UPDATE_SET_NULL));
+
+		if (index == NULL
+		    && !(ignore_err & DICT_ERR_IGNORE_FK_NOKEY)) {
+			dict_foreign_error_report(
+				ef, for_in_cache,
+				"there is no index in the table"
+				" which would contain\n"
+				"the columns as the first columns,"
+				" or the data types in the\n"
+				"table do not match"
+				" the ones in the referenced table\n"
+				"or one of the ON ... SET NULL columns"
+				" is declared NOT NULL.");
+
+			if (for_in_cache == foreign) {
+				if (added_to_referenced_list) {
+					const dict_foreign_set::size_type
+						n = ref_table->referenced_set
+						  .erase(for_in_cache);
+
+					ut_a(n == 1);	/* the number of
+							elements removed must
+							be one */
+				}
+
+				dict_foreign_free(foreign);
+			}
+
+			DBUG_RETURN(DB_CANNOT_ADD_CONSTRAINT);
+		}
+
+		for_in_cache->foreign_table = for_table;
+		for_in_cache->foreign_index = index;
+
+		std::pair<dict_foreign_set::iterator, bool>	ret
+			= for_table->foreign_set.insert(for_in_cache);
+
+		ut_a(ret.second);	/* second is true if the insertion
+					took place */
+	}
+
+	/* We need to move the table to the non-LRU end of the table LRU
+	list. Otherwise it will be evicted from the cache. */
+
+	if (ref_table != NULL) {
+		dict_sys.prevent_eviction(ref_table);
+	}
+
+	if (for_table != NULL) {
+		dict_sys.prevent_eviction(for_table);
+	}
+
+	ut_ad(dict_lru_validate());
+	DBUG_RETURN(DB_SUCCESS);
+}
+
+/*********************************************************************//**
+Scans from pointer onwards. Stops if is at the start of a copy of
+'string' where characters are compared without case sensitivity, and
+only outside `` or "" quotes. Stops also at NUL.
+@return scanned up to this */
+static
+const char*
+dict_scan_to(
+/*=========*/
+	const char*	ptr,	/*!< in: scan from */
+	const char*	string)	/*!< in: look for this */
+{
+	char	quote	= '\0';
+	bool	escape	= false;
+
+	for (; *ptr; ptr++) {
+		if (*ptr == quote) {
+			/* Closing quote character: do not look for
+			starting quote or the keyword. */
+
+			/* If the quote character is escaped by a
+			backslash, ignore it. */
+			if (escape) {
+				escape = false;
+			} else {
+				quote = '\0';
+			}
+		} else if (quote) {
+			/* Within quotes: do nothing. */
+			if (escape) {
+				escape = false;
+			} else if (*ptr == '\\') {
+				escape = true;
+			}
+		} else if (*ptr == '`' || *ptr == '"' || *ptr == '\'') {
+			/* Starting quote: remember the quote character. */
+			quote = *ptr;
+		} else {
+			/* Outside quotes: look for the keyword. */
+			ulint	i;
+			for (i = 0; string[i]; i++) {
+				if (toupper((int)(unsigned char)(ptr[i]))
+				    != toupper((int)(unsigned char)
+					       (string[i]))) {
+					goto nomatch;
+				}
+			}
+			break;
+nomatch:
+			;
+		}
+	}
+
+	return(ptr);
+}
+
+/*********************************************************************//**
+Accepts a specified string. Comparisons are case-insensitive.
+@return if string was accepted, the pointer is moved after that, else
+ptr is returned */
+static
+const char*
+dict_accept(
+/*========*/
+	CHARSET_INFO*	cs,	/*!< in: the character set of ptr */
+	const char*	ptr,	/*!< in: scan from this */
+	const char*	string,	/*!< in: accept only this string as the next
+				non-whitespace string */
+	ibool*		success)/*!< out: TRUE if accepted */
+{
+	const char*	old_ptr = ptr;
+	const char*	old_ptr2;
+
+	*success = FALSE;
+
+	while (my_isspace(cs, *ptr)) {
+		ptr++;
+	}
+
+	old_ptr2 = ptr;
+
+	ptr = dict_scan_to(ptr, string);
+
+	if (*ptr == '\0' || old_ptr2 != ptr) {
+		return(old_ptr);
+	}
+
+	*success = TRUE;
+
+	return ptr + strlen(string);
+}
+
+/*********************************************************************//**
+Scans an id. For the lexical definition of an 'id', see the code below.
+Strips backquotes or double quotes from around the id.
+@return scanned to */
+static
+const char*
+dict_scan_id(
+/*=========*/
+	CHARSET_INFO*	cs,	/*!< in: the character set of ptr */
+	const char*	ptr,	/*!< in: scanned to */
+	mem_heap_t*	heap,	/*!< in: heap where to allocate the id
+				(NULL=id will not be allocated, but it
+				will point to string near ptr) */
+	const char**	id,	/*!< out,own: the id; NULL if no id was
+				scannable */
+	ibool		table_id,/*!< in: TRUE=convert the allocated id
+				as a table name; FALSE=convert to UTF-8 */
+	ibool		accept_also_dot)
+				/*!< in: TRUE if also a dot can appear in a
+				non-quoted id; in a quoted id it can appear
+				always */
+{
+	char		quote	= '\0';
+	ulint		len	= 0;
+	const char*	s;
+	char*		str;
+	char*		dst;
+
+	*id = NULL;
+
+	while (my_isspace(cs, *ptr)) {
+		ptr++;
+	}
+
+	if (*ptr == '\0') {
+
+		return(ptr);
+	}
+
+	if (*ptr == '`' || *ptr == '"') {
+		quote = *ptr++;
+	}
+
+	s = ptr;
+
+	if (quote) {
+		for (;;) {
+			if (!*ptr) {
+				/* Syntax error */
+				return(ptr);
+			}
+			if (*ptr == quote) {
+				ptr++;
+				if (*ptr != quote) {
+					break;
+				}
+			}
+			ptr++;
+			len++;
+		}
+	} else {
+		while (!my_isspace(cs, *ptr) && *ptr != '(' && *ptr != ')'
+		       && (accept_also_dot || *ptr != '.')
+		       && *ptr != ',' && *ptr != '\0') {
+
+			ptr++;
+		}
+
+		len = ulint(ptr - s);
+	}
+
+	if (heap == NULL) {
+		/* no heap given: id will point to source string */
+		*id = s;
+		return(ptr);
+	}
+
+	if (quote) {
+		char*	d;
+
+		str = d = static_cast<char*>(
+			mem_heap_alloc(heap, len + 1));
+
+		while (len--) {
+			if ((*d++ = *s++) == quote) {
+				s++;
+			}
+		}
+		*d++ = 0;
+		len = ulint(d - str);
+		ut_ad(*s == quote);
+		ut_ad(s + 1 == ptr);
+	} else {
+		str = mem_heap_strdupl(heap, s, len);
+	}
+
+	if (!table_id) {
+convert_id:
+		/* Convert the identifier from connection character set
+		to UTF-8. */
+		len = 3 * len + 1;
+		*id = dst = static_cast<char*>(mem_heap_alloc(heap, len));
+
+		innobase_convert_from_id(cs, dst, str, len);
+	} else if (!strncmp(str, srv_mysql50_table_name_prefix,
+			    sizeof(srv_mysql50_table_name_prefix) - 1)) {
+		/* This is a pre-5.1 table name
+		containing chars other than [A-Za-z0-9].
+		Discard the prefix and use raw UTF-8 encoding. */
+		str += sizeof(srv_mysql50_table_name_prefix) - 1;
+		len -= sizeof(srv_mysql50_table_name_prefix) - 1;
+		goto convert_id;
+	} else {
+		/* Encode using filename-safe characters. */
+		len = 5 * len + 1;
+		*id = dst = static_cast<char*>(mem_heap_alloc(heap, len));
+
+		innobase_convert_from_table_id(cs, dst, str, len);
+	}
+
+	return(ptr);
+}
+
+/*********************************************************************//**
+Open a table from its database and table name, this is currently used by
+foreign constraint parser to get the referenced table.
+@return complete table name with database and table name, allocated from
+heap memory passed in */
+char*
+dict_get_referenced_table(
+	const char*    name,		  /*!< in: foreign key table name */
+	const char*    database_name,	  /*!< in: table db name */
+	ulint	       database_name_len, /*!< in: db name length */
+	const char*    table_name,	  /*!< in: table name */
+	ulint	       table_name_len,	  /*!< in: table name length */
+	dict_table_t** table,		  /*!< out: table object or NULL */
+	mem_heap_t*    heap,		  /*!< in/out: heap memory */
+	CHARSET_INFO*  from_cs)		  /*!< in: table name charset */
+{
+	char*		ref;
+	char		db_name[MAX_DATABASE_NAME_LEN];
+	char		tbl_name[MAX_TABLE_NAME_LEN];
+	CHARSET_INFO*	to_cs = &my_charset_filename;
+	uint		errors;
+	ut_ad(database_name || name);
+	ut_ad(table_name);
+
+	if (!strncmp(table_name, srv_mysql50_table_name_prefix,
+		     sizeof(srv_mysql50_table_name_prefix) - 1)) {
+		/* This is a pre-5.1 table name
+		containing chars other than [A-Za-z0-9].
+		Discard the prefix and use raw UTF-8 encoding. */
+		table_name += sizeof(srv_mysql50_table_name_prefix) - 1;
+		table_name_len -= sizeof(srv_mysql50_table_name_prefix) - 1;
+
+		to_cs = system_charset_info;
+	}
+
+	table_name_len = strconvert(from_cs, table_name, table_name_len, to_cs,
+				    tbl_name, MAX_TABLE_NAME_LEN, &errors);
+	table_name     = tbl_name;
+
+	if (database_name) {
+		to_cs = &my_charset_filename;
+		if (!strncmp(database_name, srv_mysql50_table_name_prefix,
+			     sizeof(srv_mysql50_table_name_prefix) - 1)) {
+			database_name
+				+= sizeof(srv_mysql50_table_name_prefix) - 1;
+			database_name_len
+				-= sizeof(srv_mysql50_table_name_prefix) - 1;
+			to_cs = system_charset_info;
+		}
+
+		database_name_len = strconvert(
+			from_cs, database_name, database_name_len, to_cs,
+			db_name, MAX_DATABASE_NAME_LEN, &errors);
+		database_name = db_name;
+	} else {
+		/* Use the database name of the foreign key table */
+
+		database_name = name;
+		database_name_len = dict_get_db_name_len(name);
+	}
+
+	/* Copy database_name, '/', table_name, '\0' */
+	const size_t len = database_name_len + table_name_len + 1;
+	ref = static_cast<char*>(mem_heap_alloc(heap, len + 1));
+	memcpy(ref, database_name, database_name_len);
+	ref[database_name_len] = '/';
+	memcpy(ref + database_name_len + 1, table_name, table_name_len + 1);
+
+	/* Values;  0 = Store and compare as given; case sensitive
+	            1 = Store and compare in lower; case insensitive
+	            2 = Store as given, compare in lower; case semi-sensitive */
+	if (lower_case_table_names == 2) {
+		innobase_casedn_str(ref);
+		*table = dict_sys.load_table({ref, len});
+		memcpy(ref, database_name, database_name_len);
+		ref[database_name_len] = '/';
+		memcpy(ref + database_name_len + 1, table_name, table_name_len + 1);
+
+	} else {
+#ifndef _WIN32
+		if (lower_case_table_names == 1) {
+			innobase_casedn_str(ref);
+		}
+#else
+		innobase_casedn_str(ref);
+#endif /* !_WIN32 */
+		*table = dict_sys.load_table({ref, len});
+	}
+
+	return(ref);
+}
+
+/*********************************************************************//**
+Removes MySQL comments from an SQL string. A comment is either
+(a) '#' to the end of the line,
+(b) '--[space]' to the end of the line, or
+(c) '[slash][asterisk]' till the next '[asterisk][slash]' (like the familiar
+C comment syntax).
+@return own: SQL string stripped from comments; the caller must free
+this with ut_free()! */
+static
+char*
+dict_strip_comments(
+/*================*/
+	const char*	sql_string,	/*!< in: SQL string */
+	size_t		sql_length)	/*!< in: length of sql_string */
+{
+	char*		str;
+	const char*	sptr;
+	const char*	eptr	= sql_string + sql_length;
+	char*		ptr;
+	/* unclosed quote character (0 if none) */
+	char		quote	= 0;
+	bool		escape = false;
+
+	DBUG_ENTER("dict_strip_comments");
+
+	DBUG_PRINT("dict_strip_comments", ("%s", sql_string));
+
+	str = static_cast<char*>(ut_malloc_nokey(sql_length + 1));
+
+	sptr = sql_string;
+	ptr = str;
+
+	for (;;) {
+scan_more:
+		if (sptr >= eptr || *sptr == '\0') {
+end_of_string:
+			*ptr = '\0';
+
+			ut_a(ptr <= str + sql_length);
+
+			DBUG_PRINT("dict_strip_comments", ("%s", str));
+			DBUG_RETURN(str);
+		}
+
+		if (*sptr == quote) {
+			/* Closing quote character: do not look for
+			starting quote or comments. */
+
+			/* If the quote character is escaped by a
+			backslash, ignore it. */
+			if (escape) {
+				escape = false;
+			} else {
+				quote = 0;
+			}
+		} else if (quote) {
+			/* Within quotes: do not look for
+			starting quotes or comments. */
+			if (escape) {
+				escape = false;
+			} else if (*sptr == '\\') {
+				escape = true;
+			}
+		} else if (*sptr == '"' || *sptr == '`' || *sptr == '\'') {
+			/* Starting quote: remember the quote character. */
+			quote = *sptr;
+		} else if (*sptr == '#'
+			   || (sptr[0] == '-' && sptr[1] == '-'
+			       && sptr[2] == ' ')) {
+			for (;;) {
+				if (++sptr >= eptr) {
+					goto end_of_string;
+				}
+
+				/* In Unix a newline is 0x0A while in Windows
+				it is 0x0D followed by 0x0A */
+
+				switch (*sptr) {
+				case (char) 0X0A:
+				case (char) 0x0D:
+				case '\0':
+					goto scan_more;
+				}
+			}
+		} else if (!quote && *sptr == '/' && *(sptr + 1) == '*') {
+			sptr += 2;
+			for (;;) {
+				if (sptr >= eptr) {
+					goto end_of_string;
+				}
+
+				switch (*sptr) {
+				case '\0':
+					goto scan_more;
+				case '*':
+					if (sptr[1] == '/') {
+						sptr += 2;
+						goto scan_more;
+					}
+				}
+
+				sptr++;
+			}
+		}
+
+		*ptr = *sptr;
+
+		ptr++;
+		sptr++;
+	}
+}
+
+/*********************************************************************//**
+Finds the highest [number] for foreign key constraints of the table. Looks
+only at the >= 4.0.18-format id's, which are of the form
+databasename/tablename_ibfk_[number].
+@return highest number, 0 if table has no new format foreign key constraints */
+ulint
+dict_table_get_highest_foreign_id(
+/*==============================*/
+	dict_table_t*	table)	/*!< in: table in the dictionary memory cache */
+{
+	dict_foreign_t*	foreign;
+	char*		endp;
+	ulint		biggest_id	= 0;
+	ulint		id;
+	ulint		len;
+
+	DBUG_ENTER("dict_table_get_highest_foreign_id");
+
+	ut_a(table);
+
+	len = strlen(table->name.m_name);
+
+	for (dict_foreign_set::iterator it = table->foreign_set.begin();
+	     it != table->foreign_set.end();
+	     ++it) {
+		char    fkid[MAX_TABLE_NAME_LEN * 2 + 20];
+		foreign = *it;
+
+		strncpy(fkid, foreign->id, (sizeof fkid) - 1);
+		fkid[(sizeof fkid) - 1] = '\0';
+		/* Convert foreign key identifier on dictionary memory
+		cache to filename charset. */
+		innobase_convert_to_filename_charset(
+				strchr(fkid, '/') + 1,
+				strchr(foreign->id, '/') + 1,
+				MAX_TABLE_NAME_LEN);
+
+		if (strlen(fkid) > ((sizeof dict_ibfk) - 1) + len
+		    && 0 == memcmp(fkid, table->name.m_name, len)
+		    && 0 == memcmp(fkid + len,
+				   dict_ibfk, (sizeof dict_ibfk) - 1)
+		    && fkid[len + ((sizeof dict_ibfk) - 1)] != '0') {
+			/* It is of the >= 4.0.18 format */
+
+			id = strtoul(fkid + len
+				     + ((sizeof dict_ibfk) - 1),
+				     &endp, 10);
+			if (*endp == '\0') {
+				ut_a(id != biggest_id);
+
+				if (id > biggest_id) {
+					biggest_id = id;
+				}
+			}
+		}
+	}
+
+	DBUG_PRINT("dict_table_get_highest_foreign_id",
+		   ("id: " ULINTPF, biggest_id));
+
+	DBUG_RETURN(biggest_id);
+}
+
+/**********************************************************************//**
+Parses the CONSTRAINT id's to be dropped in an ALTER TABLE statement.
+@return DB_SUCCESS or DB_CANNOT_DROP_CONSTRAINT if syntax error or the
+constraint id does not match */
+dberr_t
+dict_foreign_parse_drop_constraints(
+/*================================*/
+	mem_heap_t*	heap,			/*!< in: heap from which we can
+						allocate memory */
+	trx_t*		trx,			/*!< in: transaction */
+	dict_table_t*	table,			/*!< in: table */
+	ulint*		n,			/*!< out: number of constraints
+						to drop */
+	const char***	constraints_to_drop)	/*!< out: id's of the
+						constraints to drop */
+{
+	ibool			success;
+	char*			str;
+	size_t			len;
+	const char*		ptr;
+	const char*		ptr1;
+	const char*		id;
+	CHARSET_INFO*		cs;
+
+	ut_a(trx->mysql_thd);
+
+	cs = thd_charset(trx->mysql_thd);
+
+	*n = 0;
+
+	*constraints_to_drop = static_cast<const char**>(
+		mem_heap_alloc(heap, 1000 * sizeof(char*)));
+
+	ptr = innobase_get_stmt_unsafe(trx->mysql_thd, &len);
+
+	str = dict_strip_comments(ptr, len);
+
+	ptr = str;
+
+	ut_ad(dict_sys.locked());
+loop:
+	ptr = dict_scan_to(ptr, "DROP");
+
+	if (*ptr == '\0') {
+		ut_free(str);
+
+		return(DB_SUCCESS);
+	}
+
+	ptr = dict_accept(cs, ptr, "DROP", &success);
+
+	if (!my_isspace(cs, *ptr)) {
+
+		goto loop;
+	}
+
+	ptr = dict_accept(cs, ptr, "FOREIGN", &success);
+
+	if (!success || !my_isspace(cs, *ptr)) {
+
+		goto loop;
+	}
+
+	ptr = dict_accept(cs, ptr, "KEY", &success);
+
+	if (!success) {
+
+		goto syntax_error;
+	}
+
+	ptr1 = dict_accept(cs, ptr, "IF", &success);
+
+	if (success && my_isspace(cs, *ptr1)) {
+		ptr1 = dict_accept(cs, ptr1, "EXISTS", &success);
+		if (success) {
+			ptr = ptr1;
+		}
+	}
+
+	ptr = dict_scan_id(cs, ptr, heap, &id, FALSE, TRUE);
+
+	if (id == NULL) {
+
+		goto syntax_error;
+	}
+
+	ut_a(*n < 1000);
+	(*constraints_to_drop)[*n] = id;
+	(*n)++;
+
+	if (std::find_if(table->foreign_set.begin(),
+			 table->foreign_set.end(),
+			 dict_foreign_matches_id(id))
+	    == table->foreign_set.end()) {
+
+		if (!srv_read_only_mode) {
+			FILE*	ef = dict_foreign_err_file;
+
+			mysql_mutex_lock(&dict_foreign_err_mutex);
+			rewind(ef);
+			ut_print_timestamp(ef);
+			fputs(" Error in dropping of a foreign key"
+			      " constraint of table ", ef);
+			ut_print_name(ef, NULL, table->name.m_name);
+			fprintf(ef, ",\nin SQL command\n%s"
+				"\nCannot find a constraint with the"
+				" given id %s.\n", str, id);
+			mysql_mutex_unlock(&dict_foreign_err_mutex);
+		}
+
+		ut_free(str);
+
+		return(DB_CANNOT_DROP_CONSTRAINT);
+	}
+
+	goto loop;
+
+syntax_error:
+	if (!srv_read_only_mode) {
+		FILE*	ef = dict_foreign_err_file;
+
+		mysql_mutex_lock(&dict_foreign_err_mutex);
+		rewind(ef);
+		ut_print_timestamp(ef);
+		fputs(" Syntax error in dropping of a"
+		      " foreign key constraint of table ", ef);
+		ut_print_name(ef, NULL, table->name.m_name);
+		fprintf(ef, ",\n"
+			"close to:\n%s\n in SQL command\n%s\n", ptr, str);
+		mysql_mutex_unlock(&dict_foreign_err_mutex);
+	}
+
+	ut_free(str);
+
+	return(DB_CANNOT_DROP_CONSTRAINT);
+}
+
+/*==================== END OF FOREIGN KEY PROCESSING ====================*/
+
+/**********************************************************************//**
+Returns an index object if it is found in the dictionary cache.
+Assumes that dict_sys.latch is already being held.
+@return index, NULL if not found */
+dict_index_t*
+dict_index_get_if_in_cache_low(
+/*===========================*/
+	index_id_t	index_id)	/*!< in: index id */
+{
+  ut_ad(dict_sys.frozen());
+
+  for (dict_table_t *table= UT_LIST_GET_FIRST(dict_sys.table_LRU);
+       table; table= UT_LIST_GET_NEXT(table_LRU, table))
+    if (dict_index_t *index= dict_table_find_index_on_id(table, index_id))
+      return index;
+
+  for (dict_table_t *table = UT_LIST_GET_FIRST(dict_sys.table_non_LRU);
+       table; table= UT_LIST_GET_NEXT(table_LRU, table))
+    if (dict_index_t *index= dict_table_find_index_on_id(table, index_id))
+      return index;
+
+  return nullptr;
+}
+
+#ifdef UNIV_DEBUG
+/**********************************************************************//**
+Returns an index object if it is found in the dictionary cache.
+@return index, NULL if not found */
+dict_index_t*
+dict_index_get_if_in_cache(
+/*=======================*/
+	index_id_t	index_id)	/*!< in: index id */
+{
+	dict_index_t*	index;
+
+	if (!dict_sys.is_initialised()) {
+		return(NULL);
+	}
+
+	dict_sys.freeze(SRW_LOCK_CALL);
+
+	index = dict_index_get_if_in_cache_low(index_id);
+
+	dict_sys.unfreeze();
+
+	return(index);
+}
+
+/**********************************************************************//**
+Checks that a tuple has n_fields_cmp value in a sensible range, so that
+no comparison can occur with the page number field in a node pointer.
+@return TRUE if ok */
+ibool
+dict_index_check_search_tuple(
+/*==========================*/
+	const dict_index_t*	index,	/*!< in: index tree */
+	const dtuple_t*		tuple)	/*!< in: tuple used in a search */
+{
+	ut_ad(dtuple_get_n_fields_cmp(tuple)
+	      <= dict_index_get_n_unique_in_tree(index));
+	return(TRUE);
+}
+#endif /* UNIV_DEBUG */
+
+/**********************************************************************//**
+Builds a node pointer out of a physical record and a page number.
+@return own: node pointer */
+dtuple_t*
+dict_index_build_node_ptr(
+/*======================*/
+	const dict_index_t*	index,	/*!< in: index */
+	const rec_t*		rec,	/*!< in: record for which to build node
+					pointer */
+	ulint			page_no,/*!< in: page number to put in node
+					pointer */
+	mem_heap_t*		heap,	/*!< in: memory heap where pointer
+					created */
+	ulint			level)	/*!< in: level of rec in tree:
+					0 means leaf level */
+{
+	dtuple_t*	tuple;
+	dfield_t*	field;
+	byte*		buf;
+	ulint		n_unique;
+
+	if (dict_index_is_ibuf(index)) {
+		/* In a universal index tree, we take the whole record as
+		the node pointer if the record is on the leaf level,
+		on non-leaf levels we remove the last field, which
+		contains the page number of the child page */
+
+		ut_a(!dict_table_is_comp(index->table));
+		n_unique = rec_get_n_fields_old(rec);
+
+		if (level > 0) {
+			ut_a(n_unique > 1);
+			n_unique--;
+		}
+	} else {
+		n_unique = dict_index_get_n_unique_in_tree_nonleaf(index);
+	}
+
+	tuple = dtuple_create(heap, n_unique + 1);
+
+	/* When searching in the tree for the node pointer, we must not do
+	comparison on the last field, the page number field, as on upper
+	levels in the tree there may be identical node pointers with a
+	different page number; therefore, we set the n_fields_cmp to one
+	less: */
+
+	dtuple_set_n_fields_cmp(tuple, n_unique);
+
+	dict_index_copy_types(tuple, index, n_unique);
+
+	buf = static_cast<byte*>(mem_heap_alloc(heap, 4));
+
+	mach_write_to_4(buf, page_no);
+
+	field = dtuple_get_nth_field(tuple, n_unique);
+	dfield_set_data(field, buf, 4);
+
+	dtype_set(dfield_get_type(field), DATA_SYS_CHILD, DATA_NOT_NULL, 4);
+
+	rec_copy_prefix_to_dtuple(tuple, rec, index,
+				  level ? 0 : index->n_core_fields,
+				  n_unique, heap);
+	dtuple_set_info_bits(tuple, dtuple_get_info_bits(tuple)
+			     | REC_STATUS_NODE_PTR);
+
+	ut_ad(dtuple_check_typed(tuple));
+
+	return(tuple);
+}
+
+/** Convert a physical record into a search tuple.
+@param[in]	rec		index record (not necessarily in an index page)
+@param[in]	index		index
+@param[in]	leaf		whether rec is in a leaf page
+@param[in]	n_fields	number of data fields
+@param[in,out]	heap		memory heap for allocation
+@return own: data tuple */
+dtuple_t*
+dict_index_build_data_tuple(
+	const rec_t*		rec,
+	const dict_index_t*	index,
+	bool			leaf,
+	ulint			n_fields,
+	mem_heap_t*		heap)
+{
+	ut_ad(!index->is_clust());
+
+	dtuple_t* tuple = dtuple_create(heap, n_fields);
+
+	dict_index_copy_types(tuple, index, n_fields);
+
+	rec_copy_prefix_to_dtuple(tuple, rec, index,
+				  leaf ? n_fields : 0, n_fields, heap);
+
+	ut_ad(dtuple_check_typed(tuple));
+
+	return(tuple);
+}
+
+/*********************************************************************//**
+Calculates the minimum record length in an index. */
+ulint
+dict_index_calc_min_rec_len(
+/*========================*/
+	const dict_index_t*	index)	/*!< in: index */
+{
+	ulint	sum	= 0;
+	ulint	i;
+	ulint	comp	= dict_table_is_comp(index->table);
+
+	if (comp) {
+		ulint nullable = 0;
+		sum = REC_N_NEW_EXTRA_BYTES;
+		for (i = 0; i < dict_index_get_n_fields(index); i++) {
+			const dict_col_t*	col
+				= dict_index_get_nth_col(index, i);
+			ulint	size = dict_col_get_fixed_size(col, comp);
+			sum += size;
+			if (!size) {
+				size = col->len;
+				sum += size < 128 ? 1 : 2;
+			}
+			if (!(col->prtype & DATA_NOT_NULL)) {
+				nullable++;
+			}
+		}
+
+		/* round the NULL flags up to full bytes */
+		sum += UT_BITS_IN_BYTES(nullable);
+
+		return(sum);
+	}
+
+	for (i = 0; i < dict_index_get_n_fields(index); i++) {
+		sum += dict_col_get_fixed_size(
+			dict_index_get_nth_col(index, i), comp);
+	}
+
+	if (sum > 127) {
+		sum += 2 * dict_index_get_n_fields(index);
+	} else {
+		sum += dict_index_get_n_fields(index);
+	}
+
+	sum += REC_N_OLD_EXTRA_BYTES;
+
+	return(sum);
+}
+
+/**********************************************************************//**
+Outputs info on a foreign key of a table in a format suitable for
+CREATE TABLE. */
+std::string
+dict_print_info_on_foreign_key_in_create_format(
+/*============================================*/
+	trx_t*		trx,		/*!< in: transaction */
+	dict_foreign_t*	foreign,	/*!< in: foreign key constraint */
+	ibool		add_newline)	/*!< in: whether to add a newline */
+{
+	const char*	stripped_id;
+	ulint	i;
+	std::string	str;
+
+	if (strchr(foreign->id, '/')) {
+		/* Strip the preceding database name from the constraint id */
+		stripped_id = foreign->id + 1
+			+ dict_get_db_name_len(foreign->id);
+	} else {
+		stripped_id = foreign->id;
+	}
+
+	str.append(",");
+
+	if (add_newline) {
+		/* SHOW CREATE TABLE wants constraints each printed nicely
+		on its own line, while error messages want no newlines
+		inserted. */
+		str.append("\n ");
+	}
+
+	str.append(" CONSTRAINT ");
+
+	str.append(innobase_quote_identifier(trx, stripped_id));
+	str.append(" FOREIGN KEY (");
+
+	for (i = 0;;) {
+		str.append(innobase_quote_identifier(trx, foreign->foreign_col_names[i]));
+
+		if (++i < foreign->n_fields) {
+			str.append(", ");
+		} else {
+			break;
+		}
+	}
+
+	str.append(") REFERENCES ");
+
+	if (dict_tables_have_same_db(foreign->foreign_table_name_lookup,
+				     foreign->referenced_table_name_lookup)) {
+		/* Do not print the database name of the referenced table */
+		str.append(ut_get_name(trx,
+			      dict_remove_db_name(
+				      foreign->referenced_table_name)));
+	} else {
+		str.append(ut_get_name(trx,
+				foreign->referenced_table_name));
+	}
+
+	str.append(" (");
+
+	for (i = 0;;) {
+		str.append(innobase_quote_identifier(trx,
+				foreign->referenced_col_names[i]));
+
+		if (++i < foreign->n_fields) {
+			str.append(", ");
+		} else {
+			break;
+		}
+	}
+
+	str.append(")");
+
+	if (foreign->type & DICT_FOREIGN_ON_DELETE_CASCADE) {
+		str.append(" ON DELETE CASCADE");
+	}
+
+	if (foreign->type & DICT_FOREIGN_ON_DELETE_SET_NULL) {
+		str.append(" ON DELETE SET NULL");
+	}
+
+	if (foreign->type & DICT_FOREIGN_ON_DELETE_NO_ACTION) {
+		str.append(" ON DELETE NO ACTION");
+	}
+
+	if (foreign->type & DICT_FOREIGN_ON_UPDATE_CASCADE) {
+		str.append(" ON UPDATE CASCADE");
+	}
+
+	if (foreign->type & DICT_FOREIGN_ON_UPDATE_SET_NULL) {
+		str.append(" ON UPDATE SET NULL");
+	}
+
+	if (foreign->type & DICT_FOREIGN_ON_UPDATE_NO_ACTION) {
+		str.append(" ON UPDATE NO ACTION");
+	}
+
+	return str;
+}
+
+/**********************************************************************//**
+Outputs info on foreign keys of a table. */
+std::string
+dict_print_info_on_foreign_keys(
+/*============================*/
+	ibool		create_table_format, /*!< in: if TRUE then print in
+				a format suitable to be inserted into
+				a CREATE TABLE, otherwise in the format
+				of SHOW TABLE STATUS */
+	trx_t*		trx,	/*!< in: transaction */
+	dict_table_t*	table)	/*!< in: table */
+{
+	dict_foreign_t*	foreign;
+	std::string 	str;
+
+	dict_sys.freeze(SRW_LOCK_CALL);
+
+	for (dict_foreign_set::iterator it = table->foreign_set.begin();
+	     it != table->foreign_set.end();
+	     ++it) {
+
+		foreign = *it;
+
+		if (create_table_format) {
+			str.append(
+				dict_print_info_on_foreign_key_in_create_format(
+					trx, foreign, TRUE));
+		} else {
+			ulint	i;
+			str.append("; (");
+
+			for (i = 0; i < foreign->n_fields; i++) {
+				if (i) {
+					str.append(" ");
+				}
+
+				str.append(innobase_quote_identifier(trx,
+						foreign->foreign_col_names[i]));
+			}
+
+			str.append(") REFER ");
+			str.append(ut_get_name(trx,
+					foreign->referenced_table_name));
+			str.append(")");
+
+			for (i = 0; i < foreign->n_fields; i++) {
+				if (i) {
+					str.append(" ");
+				}
+				str.append(innobase_quote_identifier(
+						trx,
+						foreign->referenced_col_names[i]));
+			}
+
+			str.append(")");
+
+			if (foreign->type == DICT_FOREIGN_ON_DELETE_CASCADE) {
+				str.append(" ON DELETE CASCADE");
+			}
+
+			if (foreign->type == DICT_FOREIGN_ON_DELETE_SET_NULL) {
+				str.append(" ON DELETE SET NULL");
+			}
+
+			if (foreign->type & DICT_FOREIGN_ON_DELETE_NO_ACTION) {
+				str.append(" ON DELETE NO ACTION");
+			}
+
+			if (foreign->type & DICT_FOREIGN_ON_UPDATE_CASCADE) {
+				str.append(" ON UPDATE CASCADE");
+			}
+
+			if (foreign->type & DICT_FOREIGN_ON_UPDATE_SET_NULL) {
+				str.append(" ON UPDATE SET NULL");
+			}
+
+			if (foreign->type & DICT_FOREIGN_ON_UPDATE_NO_ACTION) {
+				str.append(" ON UPDATE NO ACTION");
+			}
+		}
+	}
+
+	dict_sys.unfreeze();
+	return str;
+}
+
+/**********************************************************************//**
+Flags an index corrupted both in the data dictionary cache
+and in the SYS_INDEXES */
+void dict_set_corrupted(dict_index_t *index, const char *ctx)
+{
+	mem_heap_t*	heap;
+	mtr_t		mtr;
+	dict_index_t*	sys_index;
+	dtuple_t*	tuple;
+	dfield_t*	dfield;
+	byte*		buf;
+	const char*	status;
+	btr_cur_t	cursor;
+
+	dict_sys.lock(SRW_LOCK_CALL);
+
+	ut_ad(!dict_table_is_comp(dict_sys.sys_tables));
+	ut_ad(!dict_table_is_comp(dict_sys.sys_indexes));
+
+	/* Mark the table as corrupted only if the clustered index
+	is corrupted */
+	if (dict_index_is_clust(index)) {
+		index->table->corrupted = TRUE;
+		goto func_exit;
+	}
+
+	if (index->type & DICT_CORRUPT) {
+		/* The index was already flagged corrupted. */
+		ut_ad(!dict_index_is_clust(index) || index->table->corrupted);
+		goto func_exit;
+	}
+
+	/* If this is read only mode, do not update SYS_INDEXES, just
+	mark it as corrupted in memory */
+	if (high_level_read_only) {
+		index->type |= DICT_CORRUPT;
+		goto func_exit;
+	}
+
+	heap = mem_heap_create(sizeof(dtuple_t) + 2 * (sizeof(dfield_t)
+			       + sizeof(que_fork_t) + sizeof(upd_node_t)
+			       + sizeof(upd_t) + 12));
+	mtr_start(&mtr);
+	index->type |= DICT_CORRUPT;
+
+	sys_index = UT_LIST_GET_FIRST(dict_sys.sys_indexes->indexes);
+
+	/* Find the index row in SYS_INDEXES */
+	tuple = dtuple_create(heap, 2);
+
+	dfield = dtuple_get_nth_field(tuple, 0);
+	buf = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(buf, index->table->id);
+	dfield_set_data(dfield, buf, 8);
+
+	dfield = dtuple_get_nth_field(tuple, 1);
+	buf = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(buf, index->id);
+	dfield_set_data(dfield, buf, 8);
+
+	dict_index_copy_types(tuple, sys_index, 2);
+	cursor.page_cur.index = sys_index;
+
+	if (cursor.search_leaf(tuple, PAGE_CUR_LE, BTR_MODIFY_LEAF, &mtr)
+	    != DB_SUCCESS) {
+		goto fail;
+	}
+
+	if (cursor.low_match == dtuple_get_n_fields(tuple)) {
+		/* UPDATE SYS_INDEXES SET TYPE=index->type
+		WHERE TABLE_ID=index->table->id AND INDEX_ID=index->id */
+		ulint	len;
+		byte*	field	= rec_get_nth_field_old(
+			btr_cur_get_rec(&cursor),
+			DICT_FLD__SYS_INDEXES__TYPE, &len);
+		if (len != 4) {
+			goto fail;
+		}
+		mtr.write<4>(*btr_cur_get_block(&cursor), field, index->type);
+		status = "Flagged";
+	} else {
+fail:
+		status = "Unable to flag";
+	}
+
+	mtr_commit(&mtr);
+	mem_heap_free(heap);
+	ib::error() << status << " corruption of " << index->name
+		<< " in table " << index->table->name << " in " << ctx;
+
+func_exit:
+	dict_sys.unlock();
+}
+
+/** Sets merge_threshold in the SYS_INDEXES
+@param[in,out]	index		index
+@param[in]	merge_threshold	value to set */
+void
+dict_index_set_merge_threshold(
+	dict_index_t*	index,
+	ulint		merge_threshold)
+{
+	mem_heap_t*	heap;
+	mtr_t		mtr;
+	dict_index_t*	sys_index;
+	dtuple_t*	tuple;
+	dfield_t*	dfield;
+	byte*		buf;
+	btr_cur_t	cursor;
+
+	ut_ad(index != NULL);
+	ut_ad(!dict_table_is_comp(dict_sys.sys_tables));
+	ut_ad(!dict_table_is_comp(dict_sys.sys_indexes));
+
+	heap = mem_heap_create(sizeof(dtuple_t) + 2 * (sizeof(dfield_t)
+			       + sizeof(que_fork_t) + sizeof(upd_node_t)
+			       + sizeof(upd_t) + 12));
+
+	mtr.start();
+
+	sys_index = UT_LIST_GET_FIRST(dict_sys.sys_indexes->indexes);
+
+	/* Find the index row in SYS_INDEXES */
+	tuple = dtuple_create(heap, 2);
+
+	dfield = dtuple_get_nth_field(tuple, 0);
+	buf = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(buf, index->table->id);
+	dfield_set_data(dfield, buf, 8);
+
+	dfield = dtuple_get_nth_field(tuple, 1);
+	buf = static_cast<byte*>(mem_heap_alloc(heap, 8));
+	mach_write_to_8(buf, index->id);
+	dfield_set_data(dfield, buf, 8);
+
+	dict_index_copy_types(tuple, sys_index, 2);
+	cursor.page_cur.index = sys_index;
+
+	if (cursor.search_leaf(tuple, PAGE_CUR_GE, BTR_MODIFY_LEAF, &mtr)
+	    != DB_SUCCESS) {
+		goto func_exit;
+	}
+
+	if (cursor.up_match == dtuple_get_n_fields(tuple)
+	    && rec_get_n_fields_old(btr_cur_get_rec(&cursor))
+	       == DICT_NUM_FIELDS__SYS_INDEXES) {
+		ulint	len;
+		byte*	field	= rec_get_nth_field_old(
+			btr_cur_get_rec(&cursor),
+			DICT_FLD__SYS_INDEXES__MERGE_THRESHOLD, &len);
+
+		ut_ad(len == 4);
+		mtr.write<4,mtr_t::MAYBE_NOP>(*btr_cur_get_block(&cursor),
+					      field, merge_threshold);
+	}
+
+func_exit:
+	mtr_commit(&mtr);
+	mem_heap_free(heap);
+}
+
+#ifdef UNIV_DEBUG
+/** Sets merge_threshold for all indexes in the list of tables
+@param[in]	list	pointer to the list of tables */
+inline
+void
+dict_set_merge_threshold_list_debug(
+	UT_LIST_BASE_NODE_T(dict_table_t)*	list,
+	uint					merge_threshold_all)
+{
+	for (dict_table_t* table = UT_LIST_GET_FIRST(*list);
+	     table != NULL;
+	     table = UT_LIST_GET_NEXT(table_LRU, table)) {
+		for (dict_index_t* index = UT_LIST_GET_FIRST(table->indexes);
+		     index != NULL;
+		     index = UT_LIST_GET_NEXT(indexes, index)) {
+			index->lock.x_lock(SRW_LOCK_CALL);
+			index->merge_threshold = merge_threshold_all
+				& ((1U << 6) - 1);
+			index->lock.x_unlock();
+		}
+	}
+}
+
+/** Sets merge_threshold for all indexes in dictionary cache for debug.
+@param[in]	merge_threshold_all	value to set for all indexes */
+void
+dict_set_merge_threshold_all_debug(
+	uint	merge_threshold_all)
+{
+	dict_sys.freeze(SRW_LOCK_CALL);
+
+	dict_set_merge_threshold_list_debug(
+		&dict_sys.table_LRU, merge_threshold_all);
+	dict_set_merge_threshold_list_debug(
+		&dict_sys.table_non_LRU, merge_threshold_all);
+
+	dict_sys.unfreeze();
+}
+
+#endif /* UNIV_DEBUG */
+
+/** Get an index by name.
+@param[in]	table		the table where to look for the index
+@param[in]	name		the index name to look for
+@return index, NULL if does not exist */
+dict_index_t*
+dict_table_get_index_on_name(dict_table_t* table, const char* name)
+{
+	dict_index_t*	index;
+
+	index = dict_table_get_first_index(table);
+
+	while (index != NULL) {
+		if (index->is_committed() && !strcmp(index->name, name)) {
+			return(index);
+		}
+
+		index = dict_table_get_next_index(index);
+	}
+
+	return(NULL);
+}
+
+/**********************************************************************//**
+Replace the index passed in with another equivalent index in the
+foreign key lists of the table.
+@return whether all replacements were found */
+bool
+dict_foreign_replace_index(
+/*=======================*/
+	dict_table_t*		table,  /*!< in/out: table */
+	const char**		col_names,
+					/*!< in: column names, or NULL
+					to use table->col_names */
+	const dict_index_t*	index)	/*!< in: index to be replaced */
+{
+	bool		found	= true;
+	dict_foreign_t*	foreign;
+
+	ut_ad(index->to_be_dropped);
+	ut_ad(index->table == table);
+
+	for (dict_foreign_set::iterator it = table->foreign_set.begin();
+	     it != table->foreign_set.end();
+	     ++it) {
+
+		foreign = *it;
+		if (foreign->foreign_index == index) {
+			ut_ad(foreign->foreign_table == index->table);
+
+			dict_index_t* new_index = dict_foreign_find_index(
+				foreign->foreign_table, col_names,
+				foreign->foreign_col_names,
+				foreign->n_fields, index,
+				/*check_charsets=*/TRUE, /*check_null=*/FALSE,
+				NULL, NULL, NULL);
+			if (new_index) {
+				ut_ad(new_index->table == index->table);
+				ut_ad(!new_index->to_be_dropped);
+			} else {
+				found = false;
+			}
+
+			foreign->foreign_index = new_index;
+		}
+	}
+
+	for (dict_foreign_set::iterator it = table->referenced_set.begin();
+	     it != table->referenced_set.end();
+	     ++it) {
+
+		foreign = *it;
+		if (foreign->referenced_index == index) {
+			ut_ad(foreign->referenced_table == index->table);
+
+			dict_index_t* new_index = dict_foreign_find_index(
+				foreign->referenced_table, NULL,
+				foreign->referenced_col_names,
+				foreign->n_fields, index,
+				/*check_charsets=*/TRUE, /*check_null=*/FALSE,
+				NULL, NULL, NULL);
+			/* There must exist an alternative index,
+			since this must have been checked earlier. */
+			if (new_index) {
+				ut_ad(new_index->table == index->table);
+				ut_ad(!new_index->to_be_dropped);
+			} else {
+				found = false;
+			}
+
+			foreign->referenced_index = new_index;
+		}
+	}
+
+	return(found);
+}
+
+#ifdef UNIV_DEBUG
+/**********************************************************************//**
+Check for duplicate index entries in a table [using the index name] */
+void
+dict_table_check_for_dup_indexes(
+/*=============================*/
+	const dict_table_t*	table,	/*!< in: Check for dup indexes
+					in this table */
+	enum check_name		check)	/*!< in: whether and when to allow
+					temporary index names */
+{
+	/* Check for duplicates, ignoring indexes that are marked
+	as to be dropped */
+
+	const dict_index_t*	index1;
+	const dict_index_t*	index2;
+
+	ut_ad(dict_sys.frozen());
+
+	/* The primary index _must_ exist */
+	ut_a(UT_LIST_GET_LEN(table->indexes) > 0);
+
+	index1 = UT_LIST_GET_FIRST(table->indexes);
+
+	do {
+		if (!index1->is_committed()) {
+			ut_a(!dict_index_is_clust(index1));
+
+			switch (check) {
+			case CHECK_ALL_COMPLETE:
+				ut_error;
+			case CHECK_ABORTED_OK:
+				switch (dict_index_get_online_status(index1)) {
+				case ONLINE_INDEX_COMPLETE:
+				case ONLINE_INDEX_CREATION:
+					ut_error;
+					break;
+				case ONLINE_INDEX_ABORTED:
+				case ONLINE_INDEX_ABORTED_DROPPED:
+					break;
+				}
+				/* fall through */
+			case CHECK_PARTIAL_OK:
+				break;
+			}
+		}
+
+		for (index2 = UT_LIST_GET_NEXT(indexes, index1);
+		     index2 != NULL;
+		     index2 = UT_LIST_GET_NEXT(indexes, index2)) {
+			ut_ad(index1->is_committed()
+			      != index2->is_committed()
+			      || strcmp(index1->name, index2->name) != 0);
+		}
+
+		index1 = UT_LIST_GET_NEXT(indexes, index1);
+	} while (index1);
+}
+#endif /* UNIV_DEBUG */
+
+/*********************************************************************//**
+Converts a database and table name from filesystem encoding
+(e.g. d@i1b/a@q1b@1Kc, same format as used in dict_table_t::name) in two
+strings in UTF8 encoding (e.g. dцb and aюbØc). The output buffers must be
+at least MAX_DB_UTF8_LEN and MAX_TABLE_UTF8_LEN bytes. */
+void
+dict_fs2utf8(
+/*=========*/
+	const char*	db_and_table,	/*!< in: database and table names,
+					e.g. d@i1b/a@q1b@1Kc */
+	char*		db_utf8,	/*!< out: database name, e.g. dцb */
+	size_t		db_utf8_size,	/*!< in: dbname_utf8 size */
+	char*		table_utf8,	/*!< out: table name, e.g. aюbØc */
+	size_t		table_utf8_size)/*!< in: table_utf8 size */
+{
+	char	db[MAX_DATABASE_NAME_LEN + 1];
+	ulint	db_len;
+	uint	errors;
+
+	db_len = dict_get_db_name_len(db_and_table);
+
+	ut_a(db_len <= sizeof(db));
+
+	memcpy(db, db_and_table, db_len);
+	db[db_len] = '\0';
+
+	strconvert(
+		&my_charset_filename, db, uint(db_len), system_charset_info,
+		db_utf8, uint(db_utf8_size), &errors);
+
+	/* convert each # to @0023 in table name and store the result in buf */
+	const char*	table = dict_remove_db_name(db_and_table);
+	const char*	table_p;
+	char		buf[MAX_TABLE_NAME_LEN * 5 + 1];
+	char*		buf_p;
+	for (table_p = table, buf_p = buf; table_p[0] != '\0'; table_p++) {
+		if (table_p[0] != '#') {
+			buf_p[0] = table_p[0];
+			buf_p++;
+		} else {
+			buf_p[0] = '@';
+			buf_p[1] = '0';
+			buf_p[2] = '0';
+			buf_p[3] = '2';
+			buf_p[4] = '3';
+			buf_p += 5;
+		}
+		ut_a((size_t) (buf_p - buf) < sizeof(buf));
+	}
+	buf_p[0] = '\0';
+
+	errors = 0;
+	strconvert(
+		&my_charset_filename, buf, (uint) (buf_p - buf),
+		system_charset_info,
+		table_utf8, uint(table_utf8_size),
+		&errors);
+
+	if (errors != 0) {
+		snprintf(table_utf8, table_utf8_size, "%s%s",
+			    srv_mysql50_table_name_prefix, table);
+	}
+}
+
+/** Resize the hash tables based on the current buffer pool size. */
+void dict_sys_t::resize()
+{
+  ut_ad(this == &dict_sys);
+  ut_ad(is_initialised());
+  lock(SRW_LOCK_CALL);
+
+  /* all table entries are in table_LRU and table_non_LRU lists */
+  table_hash.free();
+  table_id_hash.free();
+  temp_id_hash.free();
+
+  const ulint hash_size = buf_pool_get_curr_size()
+    / (DICT_POOL_PER_TABLE_HASH * UNIV_WORD_SIZE);
+  table_hash.create(hash_size);
+  table_id_hash.create(hash_size);
+  temp_id_hash.create(hash_size);
+
+  for (dict_table_t *table= UT_LIST_GET_FIRST(table_LRU); table;
+       table= UT_LIST_GET_NEXT(table_LRU, table))
+  {
+    ut_ad(!table->is_temporary());
+    ulint fold= my_crc32c(0, table->name.m_name, strlen(table->name.m_name));
+    ulint id_fold= ut_fold_ull(table->id);
+
+    HASH_INSERT(dict_table_t, name_hash, &table_hash, fold, table);
+    HASH_INSERT(dict_table_t, id_hash, &table_id_hash, id_fold, table);
+  }
+
+  for (dict_table_t *table = UT_LIST_GET_FIRST(table_non_LRU); table;
+       table= UT_LIST_GET_NEXT(table_LRU, table))
+  {
+    ulint fold= my_crc32c(0, table->name.m_name, strlen(table->name.m_name));
+    ulint id_fold= ut_fold_ull(table->id);
+
+    HASH_INSERT(dict_table_t, name_hash, &table_hash, fold, table);
+
+    hash_table_t *id_hash= table->is_temporary()
+      ? &temp_id_hash : &table_id_hash;
+
+    HASH_INSERT(dict_table_t, id_hash, id_hash, id_fold, table);
+  }
+
+  unlock();
+}
+
+/** Close the data dictionary cache on shutdown. */
+void dict_sys_t::close()
+{
+  ut_ad(this == &dict_sys);
+  if (!is_initialised()) return;
+
+  lock(SRW_LOCK_CALL);
+
+  /* Free the hash elements. We don't remove them from table_hash
+  because we are invoking table_hash.free() below. */
+  for (ulint i= table_hash.n_cells; i--; )
+    while (dict_table_t *table= static_cast<dict_table_t*>
+           (HASH_GET_FIRST(&table_hash, i)))
+      dict_sys.remove(table);
+
+  table_hash.free();
+
+  /* table_id_hash contains the same elements as in table_hash,
+  therefore we don't delete the individual elements. */
+  table_id_hash.free();
+
+  /* No temporary tables should exist at this point. */
+  temp_id_hash.free();
+
+  unlock();
+  latch.destroy();
+
+  mysql_mutex_destroy(&dict_foreign_err_mutex);
+
+  if (dict_foreign_err_file)
+  {
+    my_fclose(dict_foreign_err_file, MYF(MY_WME));
+    dict_foreign_err_file = NULL;
+  }
+
+  m_initialised= false;
+}
+
+#ifdef UNIV_DEBUG
+/**********************************************************************//**
+Validate the dictionary table LRU list.
+@return TRUE if valid */
+static
+ibool
+dict_lru_validate(void)
+/*===================*/
+{
+	dict_table_t*	table;
+
+	ut_ad(dict_sys.frozen());
+
+	for (table = UT_LIST_GET_FIRST(dict_sys.table_LRU);
+	     table != NULL;
+	     table = UT_LIST_GET_NEXT(table_LRU, table)) {
+
+		ut_a(table->can_be_evicted);
+	}
+
+	for (table = UT_LIST_GET_FIRST(dict_sys.table_non_LRU);
+	     table != NULL;
+	     table = UT_LIST_GET_NEXT(table_LRU, table)) {
+
+		ut_a(!table->can_be_evicted);
+	}
+
+	return(TRUE);
+}
+#endif /* UNIV_DEBUG */
+/*********************************************************************//**
+Check an index to see whether its first fields are the columns in the array,
+in the same order and is not marked for deletion and is not the same
+as types_idx.
+@return true if the index qualifies, otherwise false */
+bool
+dict_foreign_qualify_index(
+/*=======================*/
+	const dict_table_t*	table,	/*!< in: table */
+	const char**		col_names,
+					/*!< in: column names, or NULL
+					to use table->col_names */
+	const char**		columns,/*!< in: array of column names */
+	ulint			n_cols,	/*!< in: number of columns */
+	const dict_index_t*	index,	/*!< in: index to check */
+	const dict_index_t*	types_idx,
+					/*!< in: NULL or an index
+					whose types the column types
+					must match */
+	bool			check_charsets,
+					/*!< in: whether to check
+					charsets.  only has an effect
+					if types_idx != NULL */
+	ulint			check_null,
+					/*!< in: nonzero if none of
+					the columns must be declared
+					NOT NULL */
+	fkerr_t*		error,	/*!< out: error code */
+	ulint*			err_col_no,
+					/*!< out: column number where
+					error happened */
+	dict_index_t**		err_index)
+					/*!< out: index where error
+					happened */
+{
+	if (dict_index_get_n_fields(index) < n_cols) {
+		return(false);
+	}
+
+	if (!index->is_btree()) {
+		return false;
+	}
+
+	if (index->online_status >= ONLINE_INDEX_ABORTED) {
+		return false;
+	}
+
+	for (ulint i = 0; i < n_cols; i++) {
+		dict_field_t*	field;
+		const char*	col_name;
+		ulint		col_no;
+
+		field = dict_index_get_nth_field(index, i);
+		col_no = dict_col_get_no(field->col);
+
+		if (field->prefix_len != 0) {
+			/* We do not accept column prefix
+			indexes here */
+			if (error && err_col_no && err_index) {
+				*error = FK_IS_PREFIX_INDEX;
+				*err_col_no = i;
+				*err_index = (dict_index_t*)index;
+			}
+			return(false);
+		}
+
+		if (check_null
+		    && (field->col->prtype & DATA_NOT_NULL)) {
+			if (error && err_col_no && err_index) {
+				*error = FK_COL_NOT_NULL;
+				*err_col_no = i;
+				*err_index = (dict_index_t*)index;
+			}
+			return(false);
+		}
+
+		if (field->col->is_virtual()) {
+			col_name = "";
+			for (ulint j = 0; j < table->n_v_def; j++) {
+				col_name = dict_table_get_v_col_name(table, j);
+				if (innobase_strcasecmp(field->name,col_name) == 0) {
+					break;
+				}
+			}
+		} else {
+			col_name = col_names
+				? col_names[col_no]
+				: dict_table_get_col_name(table, col_no);
+		}
+
+		if (0 != innobase_strcasecmp(columns[i], col_name)) {
+			return(false);
+		}
+
+		if (types_idx && !cmp_cols_are_equal(
+			    dict_index_get_nth_col(index, i),
+			    dict_index_get_nth_col(types_idx, i),
+			    check_charsets)) {
+			if (error && err_col_no && err_index) {
+				*error = FK_COLS_NOT_EQUAL;
+				*err_col_no = i;
+				*err_index = (dict_index_t*)index;
+			}
+
+			return(false);
+		}
+	}
+
+	return(true);
+}
+
+/*********************************************************************//**
+Update the state of compression failure padding heuristics. This is
+called whenever a compression operation succeeds or fails.
+The caller must be holding info->mutex */
+static
+void
+dict_index_zip_pad_update(
+/*======================*/
+	zip_pad_info_t*	info,	/*<! in/out: info to be updated */
+	ulint	zip_threshold)	/*<! in: zip threshold value */
+{
+	ulint	total;
+	ulint	fail_pct;
+
+	ut_ad(info);
+	ut_ad(info->pad % ZIP_PAD_INCR == 0);
+
+	total = info->success + info->failure;
+
+	ut_ad(total > 0);
+
+	if (zip_threshold == 0) {
+		/* User has just disabled the padding. */
+		return;
+	}
+
+	if (total < ZIP_PAD_ROUND_LEN) {
+		/* We are in middle of a round. Do nothing. */
+		return;
+	}
+
+	/* We are at a 'round' boundary. Reset the values but first
+	calculate fail rate for our heuristic. */
+	fail_pct = (info->failure * 100) / total;
+	info->failure = 0;
+	info->success = 0;
+
+	if (fail_pct > zip_threshold) {
+		/* Compression failures are more then user defined
+		threshold. Increase the pad size to reduce chances of
+		compression failures.
+
+		Only do increment if it won't increase padding
+		beyond max pad size. */
+		if (info->pad + ZIP_PAD_INCR
+		    < (srv_page_size * zip_pad_max) / 100) {
+			info->pad.fetch_add(ZIP_PAD_INCR);
+
+			MONITOR_INC(MONITOR_PAD_INCREMENTS);
+		}
+
+		info->n_rounds = 0;
+
+	} else {
+		/* Failure rate was OK. Another successful round
+		completed. */
+		++info->n_rounds;
+
+		/* If enough successful rounds are completed with
+		compression failure rate in control, decrease the
+		padding. */
+		if (info->n_rounds >= ZIP_PAD_SUCCESSFUL_ROUND_LIMIT
+		    && info->pad > 0) {
+			info->pad.fetch_sub(ZIP_PAD_INCR);
+
+			info->n_rounds = 0;
+
+			MONITOR_INC(MONITOR_PAD_DECREMENTS);
+		}
+	}
+}
+
+/*********************************************************************//**
+This function should be called whenever a page is successfully
+compressed. Updates the compression padding information. */
+void
+dict_index_zip_success(
+/*===================*/
+	dict_index_t*	index)	/*!< in/out: index to be updated. */
+{
+	ulint zip_threshold = zip_failure_threshold_pct;
+	if (!zip_threshold) {
+		/* Disabled by user. */
+		return;
+	}
+
+	index->zip_pad.mutex.lock();
+	++index->zip_pad.success;
+	dict_index_zip_pad_update(&index->zip_pad, zip_threshold);
+	index->zip_pad.mutex.unlock();
+}
+
+/*********************************************************************//**
+This function should be called whenever a page compression attempt
+fails. Updates the compression padding information. */
+void
+dict_index_zip_failure(
+/*===================*/
+	dict_index_t*	index)	/*!< in/out: index to be updated. */
+{
+	ulint zip_threshold = zip_failure_threshold_pct;
+	if (!zip_threshold) {
+		/* Disabled by user. */
+		return;
+	}
+
+	index->zip_pad.mutex.lock();
+	++index->zip_pad.failure;
+	dict_index_zip_pad_update(&index->zip_pad, zip_threshold);
+	index->zip_pad.mutex.unlock();
+}
+
+/*********************************************************************//**
+Return the optimal page size, for which page will likely compress.
+@return page size beyond which page might not compress */
+ulint
+dict_index_zip_pad_optimal_page_size(
+/*=================================*/
+	dict_index_t*	index)	/*!< in: index for which page size
+				is requested */
+{
+	ulint	pad;
+	ulint	min_sz;
+	ulint	sz;
+
+	if (!zip_failure_threshold_pct) {
+		/* Disabled by user. */
+		return(srv_page_size);
+	}
+
+	pad = index->zip_pad.pad;
+
+	ut_ad(pad < srv_page_size);
+	sz = srv_page_size - pad;
+
+	/* Min size allowed by user. */
+	ut_ad(zip_pad_max < 100);
+	min_sz = (srv_page_size * (100 - zip_pad_max)) / 100;
+
+	return(ut_max(sz, min_sz));
+}
+
+/*************************************************************//**
+Convert table flag to row format string.
+@return row format name. */
+const char*
+dict_tf_to_row_format_string(
+/*=========================*/
+	ulint	table_flag)		/*!< in: row format setting */
+{
+	switch (dict_tf_get_rec_format(table_flag)) {
+	case REC_FORMAT_REDUNDANT:
+		return("ROW_TYPE_REDUNDANT");
+	case REC_FORMAT_COMPACT:
+		return("ROW_TYPE_COMPACT");
+	case REC_FORMAT_COMPRESSED:
+		return("ROW_TYPE_COMPRESSED");
+	case REC_FORMAT_DYNAMIC:
+		return("ROW_TYPE_DYNAMIC");
+	}
+
+	ut_error;
+	return(0);
+}
diff --git a/storage/innobase/dict/dict0load.cc b/storage/innobase/dict/dict0load.cc
new file mode 100644
index 00000000..f769839d
--- /dev/null
+++ b/storage/innobase/dict/dict0load.cc
@@ -0,0 +1,3213 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2016, 2023, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file dict/dict0load.cc
+Loads to the memory cache database object definitions
+from dictionary tables
+
+Created 4/24/1996 Heikki Tuuri
+*******************************************************/
+
+#include "dict0load.h"
+
+#include "log.h"
+#include "btr0pcur.h"
+#include "btr0btr.h"
+#include "dict0boot.h"
+#include "dict0crea.h"
+#include "dict0dict.h"
+#include "dict0mem.h"
+#include "dict0stats.h"
+#include "fsp0file.h"
+#include "fts0priv.h"
+#include "mach0data.h"
+#include "page0page.h"
+#include "rem0cmp.h"
+#include "srv0start.h"
+#include "srv0srv.h"
+#include "fts0opt.h"
+#include "row0vers.h"
+
+/** Loads a table definition and also all its index definitions.
+
+Loads those foreign key constraints whose referenced table is already in
+dictionary cache.  If a foreign key constraint is not loaded, then the
+referenced table is pushed into the output stack (fk_tables), if it is not
+NULL.  These tables must be subsequently loaded so that all the foreign
+key constraints are loaded into memory.
+
+@param[in]	name		Table name in the db/tablename format
+@param[in]	ignore_err	Error to be ignored when loading table
+				and its index definition
+@param[out]	fk_tables	Related table names that must also be
+				loaded to ensure that all foreign key
+				constraints are loaded.
+@return table, possibly with file_unreadable flag set
+@retval nullptr if the table does not exist */
+static dict_table_t *dict_load_table_one(const span<const char> &name,
+                                         dict_err_ignore_t ignore_err,
+                                         dict_names_t &fk_tables);
+
+/** Load an index definition from a SYS_INDEXES record to dict_index_t.
+@return	error message
+@retval	NULL on success */
+static
+const char*
+dict_load_index_low(
+	byte*		table_id,	/*!< in/out: table id (8 bytes),
+					an "in" value if mtr
+					and "out" when !mtr */
+	bool		uncommitted,	/*!< in: false=READ COMMITTED,
+					true=READ UNCOMMITTED */
+	mem_heap_t*	heap,		/*!< in/out: temporary memory heap */
+	const rec_t*	rec,		/*!< in: SYS_INDEXES record */
+	mtr_t*		mtr,		/*!< in/out: mini-transaction,
+					or nullptr if a pre-allocated
+					*index is to be filled in */
+	dict_table_t*	table,		/*!< in/out: table, or NULL */
+	dict_index_t**	index);		/*!< out,own: index, or NULL */
+
+/** Load a table column definition from a SYS_COLUMNS record to dict_table_t.
+@param table           table, or nullptr if the output will be in column
+@param use_uncommitted 0=READ COMMITTED, 1=detect, 2=READ UNCOMMITTED
+@param heap            memory heap for temporary storage
+@param column          pointer to output buffer, or nullptr if table!=nullptr
+@param table_id        table identifier
+@param col_name        column name
+@param rec             SYS_COLUMNS record
+@param mtr             mini-transaction
+@param nth_v_col       nullptr, or pointer to a counter of virtual columns
+@return error message
+@retval nullptr on success */
+static const char *dict_load_column_low(dict_table_t *table,
+                                        unsigned use_uncommitted,
+                                        mem_heap_t *heap, dict_col_t *column,
+                                        table_id_t *table_id,
+                                        const char **col_name,
+                                        const rec_t *rec,
+                                        mtr_t *mtr,
+                                        ulint *nth_v_col);
+
+/** Load a virtual column "mapping" (to base columns) information
+from a SYS_VIRTUAL record
+@param[in,out]	table		table
+@param[in]	uncommitted	false=READ COMMITTED, true=READ UNCOMMITTED
+@param[in,out]	column		mapped base column's dict_column_t
+@param[in,out]	table_id	table id
+@param[in,out]	pos		virtual column position
+@param[in,out]	base_pos	base column position
+@param[in]	rec		SYS_VIRTUAL record
+@return	error message
+@retval	NULL on success */
+static
+const char*
+dict_load_virtual_low(
+	dict_table_t*	table,
+	bool		uncommitted,
+	dict_col_t**	column,
+	table_id_t*	table_id,
+	ulint*		pos,
+	ulint*		base_pos,
+	const rec_t*	rec);
+
+/** Load an index field definition from a SYS_FIELDS record to dict_index_t.
+@return	error message
+@retval	NULL on success */
+static
+const char*
+dict_load_field_low(
+	byte*		index_id,	/*!< in/out: index id (8 bytes)
+					an "in" value if index != NULL
+					and "out" if index == NULL */
+	bool		uncommitted,	/*!< in: false=READ COMMITTED,
+					true=READ UNCOMMITTED */
+	dict_index_t*	index,		/*!< in/out: index, could be NULL
+					if we just populate a dict_field_t
+					struct with information from
+					a SYS_FIELDS record */
+	dict_field_t*	sys_field,	/*!< out: dict_field_t to be
+					filled */
+	ulint*		pos,		/*!< out: Field position */
+	byte*		last_index_id,	/*!< in: last index id */
+	mem_heap_t*	heap,		/*!< in/out: memory heap
+					for temporary storage */
+	mtr_t*		mtr,		/*!< in/out: mini-transaction */
+	const rec_t*	rec);		/*!< in: SYS_FIELDS record */
+
+#ifdef UNIV_DEBUG
+/****************************************************************//**
+Compare the name of an index column.
+@return TRUE if the i'th column of index is 'name'. */
+static
+ibool
+name_of_col_is(
+/*===========*/
+	const dict_table_t*	table,	/*!< in: table */
+	const dict_index_t*	index,	/*!< in: index */
+	ulint			i,	/*!< in: index field offset */
+	const char*		name)	/*!< in: name to compare to */
+{
+	ulint	tmp = dict_col_get_no(dict_field_get_col(
+					      dict_index_get_nth_field(
+						      index, i)));
+
+	return(strcmp(name, dict_table_get_col_name(table, tmp)) == 0);
+}
+#endif /* UNIV_DEBUG */
+
+/********************************************************************//**
+This function gets the next system table record as it scans the table.
+@return the next record if found, NULL if end of scan */
+static
+const rec_t*
+dict_getnext_system_low(
+/*====================*/
+	btr_pcur_t*	pcur,		/*!< in/out: persistent cursor to the
+					record*/
+	mtr_t*		mtr)		/*!< in: the mini-transaction */
+{
+	rec_t*	rec = NULL;
+
+	while (!rec) {
+		btr_pcur_move_to_next_user_rec(pcur, mtr);
+
+		rec = btr_pcur_get_rec(pcur);
+
+		if (!btr_pcur_is_on_user_rec(pcur)) {
+			/* end of index */
+			btr_pcur_close(pcur);
+
+			return(NULL);
+		}
+	}
+
+	/* Get a record, let's save the position */
+	btr_pcur_store_position(pcur, mtr);
+
+	return(rec);
+}
+
+/********************************************************************//**
+This function opens a system table, and returns the first record.
+@return first record of the system table */
+const rec_t*
+dict_startscan_system(
+/*==================*/
+	btr_pcur_t*	pcur,		/*!< out: persistent cursor to
+					the record */
+	mtr_t*		mtr,		/*!< in: the mini-transaction */
+	dict_table_t*	table)		/*!< in: system table */
+{
+  btr_pcur_init(pcur);
+  if (pcur->open_leaf(true, table->indexes.start, BTR_SEARCH_LEAF, mtr) !=
+      DB_SUCCESS)
+    return nullptr;
+  const rec_t *rec;
+  do
+    rec= dict_getnext_system_low(pcur, mtr);
+  while (rec && rec_get_deleted_flag(rec, 0));
+  return rec;
+}
+
+/********************************************************************//**
+This function gets the next system table record as it scans the table.
+@return the next record if found, NULL if end of scan */
+const rec_t*
+dict_getnext_system(
+/*================*/
+	btr_pcur_t*	pcur,		/*!< in/out: persistent cursor
+					to the record */
+	mtr_t*		mtr)		/*!< in: the mini-transaction */
+{
+  const rec_t *rec=nullptr;
+  if (pcur->restore_position(BTR_SEARCH_LEAF, mtr) != btr_pcur_t::CORRUPTED)
+    do
+      rec= dict_getnext_system_low(pcur, mtr);
+    while (rec && rec_get_deleted_flag(rec, 0));
+  return rec;
+}
+
+/********************************************************************//**
+This function parses a SYS_INDEXES record and populate a dict_index_t
+structure with the information from the record. For detail information
+about SYS_INDEXES fields, please refer to dict_boot() function.
+@return error message, or NULL on success */
+const char*
+dict_process_sys_indexes_rec(
+/*=========================*/
+	mem_heap_t*	heap,		/*!< in/out: heap memory */
+	const rec_t*	rec,		/*!< in: current SYS_INDEXES rec */
+	dict_index_t*	index,		/*!< out: index to be filled */
+	table_id_t*	table_id)	/*!< out: index table id */
+{
+  byte buf[8];
+
+  ut_d(index->is_dummy = true);
+  ut_d(index->in_instant_init = false);
+
+  /* Parse the record, and get "dict_index_t" struct filled */
+  const char *err_msg= dict_load_index_low(buf, false, heap, rec,
+                                           nullptr, nullptr, &index);
+  *table_id= mach_read_from_8(buf);
+  return err_msg;
+}
+
+/********************************************************************//**
+This function parses a SYS_COLUMNS record and populate a dict_column_t
+structure with the information from the record.
+@return error message, or NULL on success */
+const char*
+dict_process_sys_columns_rec(
+/*=========================*/
+	mem_heap_t*	heap,		/*!< in/out: heap memory */
+	const rec_t*	rec,		/*!< in: current SYS_COLUMNS rec */
+	dict_col_t*	column,		/*!< out: dict_col_t to be filled */
+	table_id_t*	table_id,	/*!< out: table id */
+	const char**	col_name,	/*!< out: column name */
+	ulint*		nth_v_col)	/*!< out: if virtual col, this is
+					record's sequence number */
+{
+	const char*	err_msg;
+
+	/* Parse the record, and get "dict_col_t" struct filled */
+	err_msg = dict_load_column_low(NULL, 0, heap, column,
+				       table_id, col_name, rec, nullptr,
+				       nth_v_col);
+
+	return(err_msg);
+}
+
+/** This function parses a SYS_VIRTUAL record and extracts virtual column
+information
+@param[in]	rec		current SYS_COLUMNS rec
+@param[in,out]	table_id	table id
+@param[in,out]	pos		virtual column position
+@param[in,out]	base_pos	base column position
+@return error message, or NULL on success */
+const char*
+dict_process_sys_virtual_rec(
+	const rec_t*	rec,
+	table_id_t*	table_id,
+	ulint*		pos,
+	ulint*		base_pos)
+{
+  return dict_load_virtual_low(nullptr, false, nullptr, table_id,
+                               pos, base_pos, rec);
+}
+
+/********************************************************************//**
+This function parses a SYS_FIELDS record and populates a dict_field_t
+structure with the information from the record.
+@return error message, or NULL on success */
+const char*
+dict_process_sys_fields_rec(
+/*========================*/
+	mem_heap_t*	heap,		/*!< in/out: heap memory */
+	const rec_t*	rec,		/*!< in: current SYS_FIELDS rec */
+	dict_field_t*	sys_field,	/*!< out: dict_field_t to be
+					filled */
+	ulint*		pos,		/*!< out: Field position */
+	index_id_t*	index_id,	/*!< out: current index id */
+	index_id_t	last_id)	/*!< in: previous index id */
+{
+	byte		buf[8];
+	byte		last_index_id[8];
+	const char*	err_msg;
+
+	mach_write_to_8(last_index_id, last_id);
+
+	err_msg = dict_load_field_low(buf, false, nullptr, sys_field,
+				      pos, last_index_id, heap, nullptr, rec);
+
+	*index_id = mach_read_from_8(buf);
+
+	return(err_msg);
+
+}
+
+/********************************************************************//**
+This function parses a SYS_FOREIGN record and populate a dict_foreign_t
+structure with the information from the record. For detail information
+about SYS_FOREIGN fields, please refer to dict_load_foreign() function.
+@return error message, or NULL on success */
+const char*
+dict_process_sys_foreign_rec(
+/*=========================*/
+	mem_heap_t*	heap,		/*!< in/out: heap memory */
+	const rec_t*	rec,		/*!< in: current SYS_FOREIGN rec */
+	dict_foreign_t*	foreign)	/*!< out: dict_foreign_t struct
+					to be filled */
+{
+	ulint		len;
+	const byte*	field;
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		return("delete-marked record in SYS_FOREIGN");
+	}
+
+	if (rec_get_n_fields_old(rec) != DICT_NUM_FIELDS__SYS_FOREIGN) {
+		return("wrong number of columns in SYS_FOREIGN record");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__ID, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+err_len:
+		return("incorrect column length in SYS_FOREIGN");
+	}
+
+	/* This receives a dict_foreign_t* that points to a stack variable.
+	So dict_foreign_free(foreign) is not used as elsewhere.
+	Since the heap used here is freed elsewhere, foreign->heap
+	is not assigned. */
+	foreign->id = mem_heap_strdupl(heap, (const char*) field, len);
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_FOREIGN__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_FOREIGN__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	/* The _lookup versions of the referenced and foreign table names
+	 are not assigned since they are not used in this dict_foreign_t */
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__FOR_NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	foreign->foreign_table_name = mem_heap_strdupl(
+		heap, (const char*) field, len);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__REF_NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	foreign->referenced_table_name = mem_heap_strdupl(
+		heap, (const char*) field, len);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__N_COLS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	uint32_t n_fields_and_type = mach_read_from_4(field);
+
+	foreign->type = n_fields_and_type >> 24 & ((1U << 6) - 1);
+	foreign->n_fields = n_fields_and_type & dict_index_t::MAX_N_FIELDS;
+
+	return(NULL);
+}
+
+/********************************************************************//**
+This function parses a SYS_FOREIGN_COLS record and extract necessary
+information from the record and return to caller.
+@return error message, or NULL on success */
+const char*
+dict_process_sys_foreign_col_rec(
+/*=============================*/
+	mem_heap_t*	heap,		/*!< in/out: heap memory */
+	const rec_t*	rec,		/*!< in: current SYS_FOREIGN_COLS rec */
+	const char**	name,		/*!< out: foreign key constraint name */
+	const char**	for_col_name,	/*!< out: referencing column name */
+	const char**	ref_col_name,	/*!< out: referenced column name
+					in referenced table */
+	ulint*		pos)		/*!< out: column position */
+{
+	ulint		len;
+	const byte*	field;
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		return("delete-marked record in SYS_FOREIGN_COLS");
+	}
+
+	if (rec_get_n_fields_old(rec) != DICT_NUM_FIELDS__SYS_FOREIGN_COLS) {
+		return("wrong number of columns in SYS_FOREIGN_COLS record");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN_COLS__ID, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+err_len:
+		return("incorrect column length in SYS_FOREIGN_COLS");
+	}
+	*name = mem_heap_strdupl(heap, (char*) field, len);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN_COLS__POS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	*pos = mach_read_from_4(field);
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_FOREIGN_COLS__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_FOREIGN_COLS__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN_COLS__FOR_COL_NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	*for_col_name = mem_heap_strdupl(heap, (char*) field, len);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN_COLS__REF_COL_NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	*ref_col_name = mem_heap_strdupl(heap, (char*) field, len);
+
+	return(NULL);
+}
+
+/** Check the validity of a SYS_TABLES record
+Make sure the fields are the right length and that they
+do not contain invalid contents.
+@param[in]	rec	SYS_TABLES record
+@return error message, or NULL on success */
+static
+const char*
+dict_sys_tables_rec_check(
+	const rec_t*	rec)
+{
+	const byte*	field;
+	ulint		len;
+
+	ut_ad(dict_sys.locked());
+
+	if (rec_get_n_fields_old(rec) != DICT_NUM_FIELDS__SYS_TABLES) {
+		return("wrong number of columns in SYS_TABLES record");
+	}
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_TABLES__NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+err_len:
+		return("incorrect column length in SYS_TABLES");
+	}
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_TABLES__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_TABLES__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	rec_get_nth_field_offs_old(rec, DICT_FLD__SYS_TABLES__ID, &len);
+	if (len != 8) {
+		goto err_len;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__N_COLS, &len);
+	if (field == NULL || len != 4) {
+		goto err_len;
+	}
+
+	rec_get_nth_field_offs_old(rec, DICT_FLD__SYS_TABLES__TYPE, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_TABLES__MIX_ID, &len);
+	if (len != 8) {
+		goto err_len;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__MIX_LEN, &len);
+	if (field == NULL || len != 4) {
+		goto err_len;
+	}
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_TABLES__CLUSTER_ID, &len);
+	if (len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__SPACE, &len);
+	if (field == NULL || len != 4) {
+		goto err_len;
+	}
+
+	return(NULL);
+}
+
+/** Check if SYS_TABLES.TYPE is valid
+@param[in]	type		SYS_TABLES.TYPE
+@param[in]	not_redundant	whether ROW_FORMAT=REDUNDANT is not used
+@return	whether the SYS_TABLES.TYPE value is valid */
+static
+bool
+dict_sys_tables_type_valid(ulint type, bool not_redundant)
+{
+	/* The DATA_DIRECTORY flag can be assigned fully independently
+	of all other persistent table flags. */
+	type &= ~DICT_TF_MASK_DATA_DIR;
+
+	if (type == 1) {
+		return(true); /* ROW_FORMAT=REDUNDANT or ROW_FORMAT=COMPACT */
+	}
+
+	if (!(type & 1)) {
+		/* For ROW_FORMAT=REDUNDANT and ROW_FORMAT=COMPACT,
+		SYS_TABLES.TYPE=1. Else, it is the same as
+		dict_table_t::flags, and the least significant bit
+		would be set. So, the bit never can be 0. */
+		return(false);
+	}
+
+	if (!not_redundant) {
+		/* SYS_TABLES.TYPE must be 1 or 1|DICT_TF_MASK_NO_ROLLBACK
+		for ROW_FORMAT=REDUNDANT. */
+		return !(type & ~(1U | DICT_TF_MASK_NO_ROLLBACK));
+	}
+
+	if (type >= 1U << DICT_TF_POS_UNUSED) {
+		/* Some unknown bits are set. */
+		return(false);
+	}
+
+	return(dict_tf_is_valid_not_redundant(type));
+}
+
+/** Convert SYS_TABLES.TYPE to dict_table_t::flags.
+@param[in]	type		SYS_TABLES.TYPE
+@param[in]	not_redundant	whether ROW_FORMAT=REDUNDANT is not used
+@return	table flags */
+static
+uint32_t dict_sys_tables_type_to_tf(uint32_t type, bool not_redundant)
+{
+	ut_ad(dict_sys_tables_type_valid(type, not_redundant));
+	uint32_t flags = not_redundant ? 1 : 0;
+
+	/* ZIP_SSIZE, ATOMIC_BLOBS, DATA_DIR, PAGE_COMPRESSION,
+	PAGE_COMPRESSION_LEVEL are the same. */
+	flags |= type & (DICT_TF_MASK_ZIP_SSIZE
+			 | DICT_TF_MASK_ATOMIC_BLOBS
+			 | DICT_TF_MASK_DATA_DIR
+			 | DICT_TF_MASK_PAGE_COMPRESSION
+			 | DICT_TF_MASK_PAGE_COMPRESSION_LEVEL
+			 | DICT_TF_MASK_NO_ROLLBACK);
+
+	ut_ad(dict_tf_is_valid(flags));
+	return(flags);
+}
+
+/** Outcome of dict_sys_tables_rec_read() */
+enum table_read_status { READ_OK= 0, READ_ERROR, READ_NOT_FOUND };
+
+/** Read and return 5 integer fields from a SYS_TABLES record.
+@param[in]	rec		A record of SYS_TABLES
+@param[in]	uncommitted	true=use READ UNCOMMITTED, false=READ COMMITTED
+@param[in]	mtr		mini-transaction
+@param[out]	table_id	Pointer to the table_id for this table
+@param[out]	space_id	Pointer to the space_id for this table
+@param[out]	n_cols		Pointer to number of columns for this table.
+@param[out]	flags		Pointer to table flags
+@param[out]	flags2		Pointer to table flags2
+@param[out]	trx_id		DB_TRX_ID of the committed SYS_TABLES record,
+				or nullptr to perform READ UNCOMMITTED
+@return whether the record was read correctly */
+MY_ATTRIBUTE((warn_unused_result))
+static
+table_read_status
+dict_sys_tables_rec_read(
+	const rec_t*		rec,
+	bool			uncommitted,
+	mtr_t*			mtr,
+	table_id_t*		table_id,
+	uint32_t*		space_id,
+	uint32_t*		n_cols,
+	uint32_t*		flags,
+	uint32_t*		flags2,
+	trx_id_t*		trx_id)
+{
+	const byte*	field;
+	ulint		len;
+	mem_heap_t*	heap = nullptr;
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__DB_TRX_ID, &len);
+	ut_ad(len == 6 || len == UNIV_SQL_NULL);
+	trx_id_t id = len == 6 ? trx_read_trx_id(field) : 0;
+	if (id && !uncommitted && trx_sys.find(nullptr, id, false)) {
+		const auto savepoint = mtr->get_savepoint();
+		heap = mem_heap_create(1024);
+		dict_index_t* index = UT_LIST_GET_FIRST(
+			dict_sys.sys_tables->indexes);
+		rec_offs* offsets = rec_get_offsets(
+			rec, index, nullptr, true, ULINT_UNDEFINED, &heap);
+		const rec_t* old_vers;
+		row_vers_build_for_semi_consistent_read(
+			nullptr, rec, mtr, index, &offsets, &heap,
+			heap, &old_vers, nullptr);
+		mtr->rollback_to_savepoint(savepoint);
+		rec = old_vers;
+		if (!rec) {
+			mem_heap_free(heap);
+			return READ_NOT_FOUND;
+		}
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_TABLES__DB_TRX_ID, &len);
+		if (UNIV_UNLIKELY(len != 6)) {
+			mem_heap_free(heap);
+			return READ_ERROR;
+		}
+		id = trx_read_trx_id(field);
+	}
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		ut_ad(id);
+		if (trx_id) {
+			return READ_NOT_FOUND;
+		}
+	}
+
+	if (trx_id) {
+		*trx_id = id;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__ID, &len);
+	ut_ad(len == 8);
+	*table_id = static_cast<table_id_t>(mach_read_from_8(field));
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__SPACE, &len);
+	ut_ad(len == 4);
+	*space_id = mach_read_from_4(field);
+
+	/* Read the 4 byte flags from the TYPE field */
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__TYPE, &len);
+	ut_a(len == 4);
+	uint32_t type = mach_read_from_4(field);
+
+	/* Handle MDEV-12873 InnoDB SYS_TABLES.TYPE incompatibility
+	for PAGE_COMPRESSED=YES in MariaDB 10.2.2 to 10.2.6.
+
+	MariaDB 10.2.2 introduced the SHARED_SPACE flag from MySQL 5.7,
+	shifting the flags PAGE_COMPRESSION, PAGE_COMPRESSION_LEVEL,
+	ATOMIC_WRITES (repurposed to NO_ROLLBACK in 10.3.1) by one bit.
+	The SHARED_SPACE flag would always
+	be written as 0 by MariaDB, because MariaDB does not support
+	CREATE TABLESPACE or CREATE TABLE...TABLESPACE for InnoDB.
+
+	So, instead of the bits AALLLLCxxxxxxx we would have
+	AALLLLC0xxxxxxx if the table was created with MariaDB 10.2.2
+	to 10.2.6. (AA=ATOMIC_WRITES, LLLL=PAGE_COMPRESSION_LEVEL,
+	C=PAGE_COMPRESSED, xxxxxxx=7 bits that were not moved.)
+
+	The case LLLLC=00000 is not a problem. The problem is the case
+	AALLLL10DB00001 where D is the (mostly ignored) DATA_DIRECTORY
+	flag and B is the ATOMIC_BLOBS flag (1 for ROW_FORMAT=DYNAMIC
+	and 0 for ROW_FORMAT=COMPACT in this case). Other low-order
+	bits must be so, because PAGE_COMPRESSED=YES is only allowed
+	for ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPACT, not for
+	ROW_FORMAT=REDUNDANT or ROW_FORMAT=COMPRESSED.
+
+	Starting with MariaDB 10.2.4, the flags would be
+	00LLLL10DB00001, because ATOMIC_WRITES is always written as 0.
+
+	We will concentrate on the PAGE_COMPRESSION_LEVEL and
+	PAGE_COMPRESSED=YES. PAGE_COMPRESSED=NO implies
+	PAGE_COMPRESSION_LEVEL=0, and in that case all the affected
+	bits will be 0. For PAGE_COMPRESSED=YES, the values 1..9 are
+	allowed for PAGE_COMPRESSION_LEVEL. That is, we must interpret
+	the bits AALLLL10DB00001 as AALLLL1DB00001.
+
+	If someone created a table in MariaDB 10.2.2 or 10.2.3 with
+	the attribute ATOMIC_WRITES=OFF (value 2) and without
+	PAGE_COMPRESSED=YES or PAGE_COMPRESSION_LEVEL, that should be
+	rejected. The value ATOMIC_WRITES=ON (1) would look like
+	ATOMIC_WRITES=OFF, but it would be ignored starting with
+	MariaDB 10.2.4. */
+	compile_time_assert(DICT_TF_POS_PAGE_COMPRESSION == 7);
+	compile_time_assert(DICT_TF_POS_UNUSED == 14);
+
+	if ((type & 0x19f) != 0x101) {
+		/* The table cannot have been created with MariaDB
+		10.2.2 to 10.2.6, because they would write the
+		low-order bits of SYS_TABLES.TYPE as 0b10xx00001 for
+		PAGE_COMPRESSED=YES. No adjustment is applicable. */
+	} else if (type >= 3 << 13) {
+		/* 10.2.2 and 10.2.3 write ATOMIC_WRITES less than 3,
+		and no other flags above that can be set for the
+		SYS_TABLES.TYPE to be in the 10.2.2..10.2.6 format.
+		This would in any case be invalid format for 10.2 and
+		earlier releases. */
+		ut_ad(!dict_sys_tables_type_valid(type, true));
+	} else {
+		/* SYS_TABLES.TYPE is of the form AALLLL10DB00001.  We
+		must still validate that the LLLL bits are between 0
+		and 9 before we can discard the extraneous 0 bit. */
+		ut_ad(!DICT_TF_GET_PAGE_COMPRESSION(type));
+
+		if ((((type >> 9) & 0xf) - 1) < 9) {
+			ut_ad(DICT_TF_GET_PAGE_COMPRESSION_LEVEL(type) & 1);
+
+			type = (type & 0x7fU) | (type >> 1 & ~0x7fU);
+
+			ut_ad(DICT_TF_GET_PAGE_COMPRESSION(type));
+			ut_ad(DICT_TF_GET_PAGE_COMPRESSION_LEVEL(type) >= 1);
+			ut_ad(DICT_TF_GET_PAGE_COMPRESSION_LEVEL(type) <= 9);
+		} else {
+			ut_ad(!dict_sys_tables_type_valid(type, true));
+		}
+	}
+
+	/* The low order bit of SYS_TABLES.TYPE is always set to 1. But in
+	dict_table_t::flags the low order bit is used to determine if the
+	ROW_FORMAT=REDUNDANT (0) or anything else (1).
+	Read the 4 byte N_COLS field and look at the high order bit.  It
+	should be set for COMPACT and later.  It should not be set for
+	REDUNDANT. */
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_TABLES__N_COLS, &len);
+	ut_a(len == 4);
+	*n_cols = mach_read_from_4(field);
+
+	const bool not_redundant = 0 != (*n_cols & DICT_N_COLS_COMPACT);
+
+	if (!dict_sys_tables_type_valid(type, not_redundant)) {
+		sql_print_error("InnoDB: Table %.*s in InnoDB"
+				" data dictionary contains invalid flags."
+				" SYS_TABLES.TYPE=" UINT32PF
+				" SYS_TABLES.N_COLS=" UINT32PF,
+				int(rec_get_field_start_offs(rec, 1)), rec,
+				type, *n_cols);
+err_exit:
+		if (UNIV_LIKELY_NULL(heap)) {
+			mem_heap_free(heap);
+		}
+		return READ_ERROR;
+	}
+
+	*flags = dict_sys_tables_type_to_tf(type, not_redundant);
+
+	/* For tables created before MySQL 4.1, there may be
+	garbage in SYS_TABLES.MIX_LEN where flags2 are found. Such tables
+	would always be in ROW_FORMAT=REDUNDANT which do not have the
+	high bit set in n_cols, and flags would be zero.
+	MySQL 4.1 was the first version to support innodb_file_per_table,
+	that is, *space_id != 0. */
+	if (not_redundant || *space_id != 0 || *n_cols & DICT_N_COLS_COMPACT
+	    || fil_system.sys_space->full_crc32()) {
+
+		/* Get flags2 from SYS_TABLES.MIX_LEN */
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_TABLES__MIX_LEN, &len);
+		*flags2 = mach_read_from_4(field);
+
+		if (!dict_tf2_is_valid(*flags, *flags2)) {
+			sql_print_error("InnoDB: Table %.*s in InnoDB"
+					" data dictionary"
+					" contains invalid flags."
+					" SYS_TABLES.TYPE=" UINT32PF
+					" SYS_TABLES.MIX_LEN=" UINT32PF,
+					int(rec_get_field_start_offs(rec, 1)),
+					rec,
+					type, *flags2);
+			goto err_exit;
+		}
+
+		/* DICT_TF2_FTS will be set when indexes are being loaded */
+		*flags2 &= ~DICT_TF2_FTS;
+
+		/* Now that we have used this bit, unset it. */
+		*n_cols &= ~DICT_N_COLS_COMPACT;
+	} else {
+		*flags2 = 0;
+	}
+
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+
+	return READ_OK;
+}
+
+/** Check each tablespace found in the data dictionary.
+Then look at each table defined in SYS_TABLES that has a space_id > 0
+to find all the file-per-table tablespaces.
+
+In a crash recovery we already have some tablespace objects created from
+processing the REDO log. We will compare the
+space_id information in the data dictionary to what we find in the
+tablespace file. In addition, more validation will be done if recovery
+was needed and force_recovery is not set.
+
+We also scan the biggest space id, and store it to fil_system. */
+void dict_check_tablespaces_and_store_max_id()
+{
+	uint32_t	max_space_id = 0;
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+
+	DBUG_ENTER("dict_check_tablespaces_and_store_max_id");
+
+	mtr.start();
+
+	dict_sys.lock(SRW_LOCK_CALL);
+
+	for (const rec_t *rec = dict_startscan_system(&pcur, &mtr,
+						      dict_sys.sys_tables);
+	     rec; rec = dict_getnext_system_low(&pcur, &mtr)) {
+		ulint		len;
+		table_id_t	table_id;
+		uint32_t	space_id;
+		uint32_t	n_cols;
+		uint32_t	flags;
+		uint32_t	flags2;
+
+		/* If a table record is not useable, ignore it and continue
+		on to the next record. Error messages were logged. */
+		if (dict_sys_tables_rec_check(rec)) {
+			continue;
+		}
+
+		const char *field = reinterpret_cast<const char*>(
+			rec_get_nth_field_old(rec, DICT_FLD__SYS_TABLES__NAME,
+					      &len));
+
+		DBUG_PRINT("dict_check_sys_tables",
+			   ("name: %*.s", static_cast<int>(len), field));
+
+		if (dict_sys_tables_rec_read(rec, false,
+					     &mtr, &table_id, &space_id,
+					     &n_cols, &flags, &flags2, nullptr)
+		    != READ_OK
+		    || space_id == TRX_SYS_SPACE) {
+			continue;
+		}
+
+		if (flags2 & DICT_TF2_DISCARDED) {
+			sql_print_information("InnoDB: Ignoring tablespace"
+					      " for %.*s because "
+					      "the DISCARD flag is set",
+					      static_cast<int>(len), field);
+			continue;
+		}
+
+		/* For tables or partitions using .ibd files, the flag
+		DICT_TF2_USE_FILE_PER_TABLE was not set in MIX_LEN
+		before MySQL 5.6.5. The flag should not have been
+		introduced in persistent storage. MariaDB will keep
+		setting the flag when writing SYS_TABLES entries for
+		newly created or rebuilt tables or partitions, but
+		will otherwise ignore the flag. */
+
+		if (fil_space_for_table_exists_in_mem(space_id, flags)) {
+			continue;
+		}
+
+		const span<const char> name{field, len};
+
+		char*	filepath = fil_make_filepath(nullptr, name,
+						     IBD, false);
+
+		const bool not_dropped{!rec_get_deleted_flag(rec, 0)};
+
+		/* Check that the .ibd file exists. */
+		if (fil_ibd_open(not_dropped, FIL_TYPE_TABLESPACE,
+				 space_id, dict_tf_to_fsp_flags(flags),
+				 name, filepath)) {
+		} else if (!not_dropped) {
+		} else if (srv_operation == SRV_OPERATION_NORMAL
+			   && srv_start_after_restore
+			   && srv_force_recovery < SRV_FORCE_NO_BACKGROUND
+			   && dict_table_t::is_temporary_name(filepath)) {
+			/* Mariabackup will not copy files whose
+			names start with #sql-. This table ought to
+			be dropped by drop_garbage_tables_after_restore()
+			a little later. */
+		} else {
+			sql_print_warning("InnoDB: Ignoring tablespace for"
+					  " %.*s because it"
+					  " could not be opened.",
+					  static_cast<int>(len), field);
+		}
+
+		max_space_id = ut_max(max_space_id, space_id);
+
+		ut_free(filepath);
+	}
+
+	mtr.commit();
+
+	fil_set_max_space_id_if_bigger(max_space_id);
+
+	dict_sys.unlock();
+
+	DBUG_VOID_RETURN;
+}
+
+/** Error message for a delete-marked record in dict_load_column_low() */
+static const char *dict_load_column_del= "delete-marked record in SYS_COLUMNS";
+/** Error message for a missing record in dict_load_column_low() */
+static const char *dict_load_column_none= "SYS_COLUMNS record not found";
+/** Message for incomplete instant ADD/DROP in dict_load_column_low() */
+static const char *dict_load_column_instant= "incomplete instant ADD/DROP";
+
+/** Load a table column definition from a SYS_COLUMNS record to dict_table_t.
+@param table           table, or nullptr if the output will be in column
+@param use_uncommitted 0=READ COMMITTED, 1=detect, 2=READ UNCOMMITTED
+@param heap            memory heap for temporary storage
+@param column          pointer to output buffer, or nullptr if table!=nullptr
+@param table_id        table identifier
+@param col_name        column name
+@param rec             SYS_COLUMNS record
+@param mtr             mini-transaction
+@param nth_v_col       nullptr, or pointer to a counter of virtual columns
+@return error message
+@retval nullptr on success */
+static const char *dict_load_column_low(dict_table_t *table,
+                                        unsigned use_uncommitted,
+                                        mem_heap_t *heap, dict_col_t *column,
+                                        table_id_t *table_id,
+                                        const char **col_name,
+                                        const rec_t *rec,
+                                        mtr_t *mtr,
+                                        ulint *nth_v_col)
+{
+	char*		name;
+	const byte*	field;
+	ulint		len;
+	ulint		mtype;
+	ulint		prtype;
+	ulint		col_len;
+	ulint		pos;
+	ulint		num_base;
+
+	ut_ad(!table == !!column);
+
+	if (rec_get_n_fields_old(rec) != DICT_NUM_FIELDS__SYS_COLUMNS) {
+		return("wrong number of columns in SYS_COLUMNS record");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__TABLE_ID, &len);
+	if (len != 8) {
+err_len:
+		return("incorrect column length in SYS_COLUMNS");
+	}
+
+	if (table_id) {
+		*table_id = mach_read_from_8(field);
+	} else if (table->id != mach_read_from_8(field)) {
+		return dict_load_column_none;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__POS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	pos = mach_read_from_4(field);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	const trx_id_t trx_id = trx_read_trx_id(field);
+
+	if (trx_id && mtr && use_uncommitted < 2
+	    && trx_sys.find(nullptr, trx_id, false)) {
+		if (use_uncommitted) {
+			return dict_load_column_instant;
+		}
+		const auto savepoint = mtr->get_savepoint();
+		dict_index_t* index = UT_LIST_GET_FIRST(
+			dict_sys.sys_columns->indexes);
+		rec_offs* offsets = rec_get_offsets(
+			rec, index, nullptr, true, ULINT_UNDEFINED, &heap);
+		const rec_t* old_vers;
+		row_vers_build_for_semi_consistent_read(
+			nullptr, rec, mtr, index, &offsets, &heap,
+			heap, &old_vers, nullptr);
+		mtr->rollback_to_savepoint(savepoint);
+		rec = old_vers;
+		if (!old_vers) {
+			return dict_load_column_none;
+		}
+		ut_ad(!rec_get_deleted_flag(rec, 0));
+	}
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		ut_ad(trx_id);
+		return dict_load_column_del;
+	}
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_COLUMNS__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	*col_name = name = mem_heap_strdupl(heap, (const char*) field, len);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__MTYPE, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	mtype = mach_read_from_4(field);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__PRTYPE, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	prtype = mach_read_from_4(field);
+
+	if (dtype_get_charset_coll(prtype) == 0
+	    && dtype_is_string_type(mtype)) {
+		/* The table was created with < 4.1.2. */
+
+		if (dtype_is_binary_string_type(mtype, prtype)) {
+			/* Use the binary collation for
+			string columns of binary type. */
+
+			prtype = dtype_form_prtype(
+				prtype,
+				DATA_MYSQL_BINARY_CHARSET_COLL);
+		} else {
+			/* Use the default charset for
+			other than binary columns. */
+
+			prtype = dtype_form_prtype(
+				prtype,
+				data_mysql_default_charset_coll);
+		}
+	}
+
+	if (table && table->n_def != pos && !(prtype & DATA_VIRTUAL)) {
+		return("SYS_COLUMNS.POS mismatch");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__LEN, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	col_len = mach_read_from_4(field);
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_COLUMNS__PREC, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	num_base = mach_read_from_4(field);
+
+	if (table) {
+		if (prtype & DATA_VIRTUAL) {
+#ifdef UNIV_DEBUG
+			dict_v_col_t*	vcol =
+#endif
+			dict_mem_table_add_v_col(
+				table, heap, name, mtype,
+				prtype, col_len,
+				dict_get_v_col_mysql_pos(pos), num_base);
+			ut_ad(vcol->v_pos == dict_get_v_col_pos(pos));
+		} else {
+			ut_ad(num_base == 0);
+			dict_mem_table_add_col(table, heap, name, mtype,
+					       prtype, col_len);
+		}
+
+		if (trx_id > table->def_trx_id) {
+			table->def_trx_id = trx_id;
+		}
+	} else {
+		dict_mem_fill_column_struct(column, pos, mtype,
+					    prtype, col_len);
+	}
+
+	/* Report the virtual column number */
+	if ((prtype & DATA_VIRTUAL) && nth_v_col != NULL) {
+		*nth_v_col = dict_get_v_col_pos(pos);
+	}
+
+	return(NULL);
+}
+
+/** Error message for a delete-marked record in dict_load_virtual_low() */
+static const char *dict_load_virtual_del= "delete-marked record in SYS_VIRTUAL";
+static const char *dict_load_virtual_none= "SYS_VIRTUAL record not found";
+
+/** Load a virtual column "mapping" (to base columns) information
+from a SYS_VIRTUAL record
+@param[in,out]	table		table
+@param[in]	uncommitted	false=READ COMMITTED, true=READ UNCOMMITTED
+@param[in,out]	column		mapped base column's dict_column_t
+@param[in,out]	table_id	table id
+@param[in,out]	pos		virtual column position
+@param[in,out]	base_pos	base column position
+@param[in]	rec		SYS_VIRTUAL record
+@return	error message
+@retval	NULL on success */
+static
+const char*
+dict_load_virtual_low(
+	dict_table_t*	table,
+	bool		uncommitted,
+	dict_col_t**	column,
+	table_id_t*	table_id,
+	ulint*		pos,
+	ulint*		base_pos,
+	const rec_t*	rec)
+{
+	const byte*	field;
+	ulint		len;
+	ulint		base;
+
+	if (rec_get_n_fields_old(rec) != DICT_NUM_FIELDS__SYS_VIRTUAL) {
+		return("wrong number of columns in SYS_VIRTUAL record");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_VIRTUAL__TABLE_ID, &len);
+	if (len != 8) {
+err_len:
+		return("incorrect column length in SYS_VIRTUAL");
+	}
+
+	if (table_id != NULL) {
+		*table_id = mach_read_from_8(field);
+	} else if (table->id != mach_read_from_8(field)) {
+		return dict_load_virtual_none;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_VIRTUAL__POS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	if (pos != NULL) {
+		*pos = mach_read_from_4(field);
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_VIRTUAL__BASE_POS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	base = mach_read_from_4(field);
+
+	if (base_pos != NULL) {
+		*base_pos = base;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_VIRTUAL__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_VIRTUAL__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	const trx_id_t trx_id = trx_read_trx_id(field);
+
+	if (trx_id && column && !uncommitted
+	    && trx_sys.find(nullptr, trx_id, false)) {
+		if (!rec_get_deleted_flag(rec, 0)) {
+			return dict_load_virtual_none;
+		}
+	} else if (rec_get_deleted_flag(rec, 0)) {
+		ut_ad(trx_id != 0);
+		return dict_load_virtual_del;
+	}
+
+	if (column != NULL) {
+		*column = dict_table_get_nth_col(table, base);
+	}
+
+	return(NULL);
+}
+
+/** Load the definitions for table columns.
+@param table           table
+@param use_uncommitted 0=READ COMMITTED, 1=detect, 2=READ UNCOMMITTED
+@param heap            memory heap for temporary storage
+@return error code
+@retval DB_SUCCESS on success
+@retval DB_SUCCESS_LOCKED_REC on success if use_uncommitted=1
+and instant ADD/DROP/reorder was detected */
+MY_ATTRIBUTE((nonnull, warn_unused_result))
+static dberr_t dict_load_columns(dict_table_t *table, unsigned use_uncommitted,
+                                 mem_heap_t *heap)
+{
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+	ulint		n_skipped = 0;
+
+	ut_ad(dict_sys.locked());
+
+	mtr.start();
+
+	dict_index_t* sys_index = dict_sys.sys_columns->indexes.start;
+	ut_ad(!dict_sys.sys_columns->not_redundant());
+
+	ut_ad(name_of_col_is(dict_sys.sys_columns, sys_index,
+			     DICT_FLD__SYS_COLUMNS__NAME, "NAME"));
+	ut_ad(name_of_col_is(dict_sys.sys_columns, sys_index,
+			     DICT_FLD__SYS_COLUMNS__PREC, "PREC"));
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+	byte table_id[8];
+	mach_write_to_8(table_id, table->id);
+	dfield_set_data(&dfield, table_id, 8);
+	dict_index_copy_types(&tuple, sys_index, 1);
+	pcur.btr_cur.page_cur.index = sys_index;
+
+	dberr_t err = btr_pcur_open_on_user_rec(&tuple,
+						BTR_SEARCH_LEAF, &pcur, &mtr);
+	if (err != DB_SUCCESS) {
+		goto func_exit;
+	}
+
+	ut_ad(table->n_t_cols == static_cast<ulint>(
+	      table->n_cols) + static_cast<ulint>(table->n_v_cols));
+
+	for (ulint i = 0;
+	     i + DATA_N_SYS_COLS < table->n_t_cols + n_skipped;
+	     i++) {
+		const char*	err_msg;
+		const char*	name = NULL;
+		ulint		nth_v_col = ULINT_UNDEFINED;
+		const rec_t*	rec = btr_pcur_get_rec(&pcur);
+
+		err_msg = btr_pcur_is_on_user_rec(&pcur)
+			? dict_load_column_low(table, use_uncommitted,
+					       heap, NULL, NULL,
+					       &name, rec, &mtr, &nth_v_col)
+			: dict_load_column_none;
+
+		if (!err_msg) {
+		} else if (err_msg == dict_load_column_del) {
+			n_skipped++;
+			goto next_rec;
+		} else if (err_msg == dict_load_column_instant) {
+			err = DB_SUCCESS_LOCKED_REC;
+			goto func_exit;
+		} else if (err_msg == dict_load_column_none
+			   && strstr(table->name.m_name,
+				     "/" TEMP_FILE_PREFIX_INNODB)) {
+			break;
+		} else {
+			ib::error() << err_msg << " for table " << table->name;
+			err = DB_CORRUPTION;
+			goto func_exit;
+		}
+
+		/* Note: Currently we have one DOC_ID column that is
+		shared by all FTS indexes on a table. And only non-virtual
+		column can be used for FULLTEXT index */
+		if (innobase_strcasecmp(name,
+					FTS_DOC_ID_COL_NAME) == 0
+		    && nth_v_col == ULINT_UNDEFINED) {
+			dict_col_t*	col;
+			/* As part of normal loading of tables the
+			table->flag is not set for tables with FTS
+			till after the FTS indexes are loaded. So we
+			create the fts_t instance here if there isn't
+			one already created.
+
+			This case does not arise for table create as
+			the flag is set before the table is created. */
+			if (table->fts == NULL) {
+				table->fts = fts_create(table);
+				table->fts->cache = fts_cache_create(table);
+				DICT_TF2_FLAG_SET(table, DICT_TF2_FTS_AUX_HEX_NAME);
+			}
+
+			ut_a(table->fts->doc_col == ULINT_UNDEFINED);
+
+			col = dict_table_get_nth_col(table, i - n_skipped);
+
+			ut_ad(col->len == sizeof(doc_id_t));
+
+			if (col->prtype & DATA_FTS_DOC_ID) {
+				DICT_TF2_FLAG_SET(
+					table, DICT_TF2_FTS_HAS_DOC_ID);
+				DICT_TF2_FLAG_UNSET(
+					table, DICT_TF2_FTS_ADD_DOC_ID);
+			}
+
+			table->fts->doc_col = i - n_skipped;
+		}
+next_rec:
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+	}
+
+func_exit:
+	mtr.commit();
+	return err;
+}
+
+/** Loads SYS_VIRTUAL info for one virtual column
+@param table	   table definition
+@param uncommitted false=READ COMMITTED, true=READ UNCOMMITTED
+@param nth_v_col   virtual column position */
+MY_ATTRIBUTE((nonnull, warn_unused_result))
+static
+dberr_t
+dict_load_virtual_col(dict_table_t *table, bool uncommitted, ulint nth_v_col)
+{
+	const dict_v_col_t* v_col = dict_table_get_nth_v_col(table, nth_v_col);
+
+	if (v_col->num_base == 0) {
+		return DB_SUCCESS;
+	}
+
+	dict_index_t*	sys_virtual_index;
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+
+	ut_ad(dict_sys.locked());
+
+	mtr.start();
+
+	sys_virtual_index = dict_sys.sys_virtual->indexes.start;
+	ut_ad(!dict_sys.sys_virtual->not_redundant());
+
+	ut_ad(name_of_col_is(dict_sys.sys_virtual, sys_virtual_index,
+			     DICT_FLD__SYS_VIRTUAL__POS, "POS"));
+
+	dfield_t dfield[2];
+	dtuple_t tuple{
+		0,2,2,dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+	byte table_id[8], vcol_pos[4];
+	mach_write_to_8(table_id, table->id);
+	dfield_set_data(&dfield[0], table_id, 8);
+	mach_write_to_4(vcol_pos,
+			dict_create_v_col_pos(nth_v_col, v_col->m_col.ind));
+	dfield_set_data(&dfield[1], vcol_pos, 4);
+
+	dict_index_copy_types(&tuple, sys_virtual_index, 2);
+	pcur.btr_cur.page_cur.index = sys_virtual_index;
+
+	dberr_t err = btr_pcur_open_on_user_rec(&tuple,
+						BTR_SEARCH_LEAF, &pcur, &mtr);
+	if (err != DB_SUCCESS) {
+		goto func_exit;
+	}
+
+	for (ulint i = 0, skipped = 0;
+	     i < unsigned{v_col->num_base} + skipped; i++) {
+		ulint		pos;
+		const char*	err_msg
+			= btr_pcur_is_on_user_rec(&pcur)
+			? dict_load_virtual_low(table, uncommitted,
+						&v_col->base_col[i - skipped],
+						NULL,
+					        &pos, NULL,
+						btr_pcur_get_rec(&pcur))
+			: dict_load_virtual_none;
+
+		if (!err_msg) {
+			ut_ad(pos == mach_read_from_4(vcol_pos));
+		} else if (err_msg == dict_load_virtual_del) {
+			skipped++;
+		} else if (err_msg == dict_load_virtual_none
+			   && strstr(table->name.m_name,
+				     "/" TEMP_FILE_PREFIX_INNODB)) {
+			break;
+		} else {
+			ib::error() << err_msg << " for table " << table->name;
+			err = DB_CORRUPTION;
+			break;
+		}
+
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+	}
+
+func_exit:
+	mtr.commit();
+	return err;
+}
+
+/** Loads info from SYS_VIRTUAL for virtual columns.
+@param table	   table definition
+@param uncommitted false=READ COMMITTED, true=READ UNCOMMITTED */
+MY_ATTRIBUTE((nonnull, warn_unused_result))
+static dberr_t dict_load_virtual(dict_table_t *table, bool uncommitted)
+{
+  for (ulint i= 0; i < table->n_v_cols; i++)
+    if (dberr_t err= dict_load_virtual_col(table, uncommitted, i))
+      return err;
+  return DB_SUCCESS;
+}
+
+/** Error message for a delete-marked record in dict_load_field_low() */
+static const char *dict_load_field_del= "delete-marked record in SYS_FIELDS";
+
+static const char *dict_load_field_none= "SYS_FIELDS record not found";
+
+/** Load an index field definition from a SYS_FIELDS record to dict_index_t.
+@return	error message
+@retval	NULL on success */
+static
+const char*
+dict_load_field_low(
+	byte*		index_id,	/*!< in/out: index id (8 bytes)
+					an "in" value if index != NULL
+					and "out" if index == NULL */
+	bool		uncommitted,	/*!< in: false=READ COMMITTED,
+					true=READ UNCOMMITTED */
+	dict_index_t*	index,		/*!< in/out: index, could be NULL
+					if we just populate a dict_field_t
+					struct with information from
+					a SYS_FIELDS record */
+	dict_field_t*	sys_field,	/*!< out: dict_field_t to be
+					filled */
+	ulint*		pos,		/*!< out: Field position */
+	byte*		last_index_id,	/*!< in: last index id */
+	mem_heap_t*	heap,		/*!< in/out: memory heap
+					for temporary storage */
+	mtr_t*		mtr,		/*!< in/out: mini-transaction */
+	const rec_t*	rec)		/*!< in: SYS_FIELDS record */
+{
+	const byte*	field;
+	ulint		len;
+	unsigned	pos_and_prefix_len;
+	unsigned	prefix_len;
+	bool		descending;
+	bool		first_field;
+	ulint		position;
+
+	/* Either index or sys_field is supplied, not both */
+	ut_ad((!index) != (!sys_field));
+	ut_ad((!index) == !mtr);
+
+	if (rec_get_n_fields_old(rec) != DICT_NUM_FIELDS__SYS_FIELDS) {
+		return("wrong number of columns in SYS_FIELDS record");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FIELDS__INDEX_ID, &len);
+	if (len != 8) {
+err_len:
+		return("incorrect column length in SYS_FIELDS");
+	}
+
+	if (!index) {
+		ut_a(last_index_id);
+		memcpy(index_id, (const char*) field, 8);
+		first_field = memcmp(index_id, last_index_id, 8);
+	} else {
+		first_field = (index->n_def == 0);
+		if (memcmp(field, index_id, 8)) {
+			return dict_load_field_none;
+		}
+	}
+
+	/* The next field stores the field position in the index and a
+	possible column prefix length if the index field does not
+	contain the whole column. The storage format is like this: if
+	there is at least one prefix field in the index, then the HIGH
+	2 bytes contain the field number (index->n_def) and the low 2
+	bytes the prefix length for the field. Otherwise the field
+	number (index->n_def) is contained in the 2 LOW bytes. */
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FIELDS__POS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	pos_and_prefix_len = mach_read_from_4(field);
+
+	if (index && UNIV_UNLIKELY
+	    ((pos_and_prefix_len & 0xFFFFUL) != index->n_def
+	     && (pos_and_prefix_len >> 16 & 0xFFFF) != index->n_def)) {
+		return("SYS_FIELDS.POS mismatch");
+	}
+
+	if (first_field || pos_and_prefix_len > 0xFFFFUL) {
+		prefix_len = pos_and_prefix_len & 0x7FFFUL;
+		descending = (pos_and_prefix_len & 0x8000UL);
+		position = (pos_and_prefix_len & 0xFFFF0000UL)  >> 16;
+	} else {
+		prefix_len = 0;
+		descending = false;
+		position = pos_and_prefix_len & 0xFFFFUL;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FIELDS__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_FIELDS__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	const trx_id_t trx_id = trx_read_trx_id(field);
+
+	if (!trx_id) {
+		ut_ad(!rec_get_deleted_flag(rec, 0));
+	} else if (!mtr || uncommitted) {
+	} else if (trx_sys.find(nullptr, trx_id, false)) {
+		const auto savepoint = mtr->get_savepoint();
+		dict_index_t* sys_field = UT_LIST_GET_FIRST(
+			dict_sys.sys_fields->indexes);
+		rec_offs* offsets = rec_get_offsets(
+			rec, sys_field, nullptr, true, ULINT_UNDEFINED, &heap);
+		const rec_t* old_vers;
+		row_vers_build_for_semi_consistent_read(
+			nullptr, rec, mtr, sys_field, &offsets, &heap,
+			heap, &old_vers, nullptr);
+		mtr->rollback_to_savepoint(savepoint);
+		rec = old_vers;
+		if (!old_vers || rec_get_deleted_flag(rec, 0)) {
+			return dict_load_field_none;
+		}
+	}
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		return(dict_load_field_del);
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FIELDS__COL_NAME, &len);
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	if (index) {
+		dict_mem_index_add_field(
+			index, mem_heap_strdupl(heap, (const char*) field, len),
+			prefix_len, descending);
+	} else {
+		sys_field->name = mem_heap_strdupl(
+			heap, (const char*) field, len);
+		sys_field->prefix_len = prefix_len & ((1U << 12) - 1);
+		sys_field->descending = descending;
+		*pos = position;
+	}
+
+	return(NULL);
+}
+
+/**
+Load definitions for index fields.
+@param index       index whose fields are to be loaded
+@param uncommitted false=READ COMMITTED, true=READ UNCOMMITTED
+@param heap        memory heap for temporary storage
+@return error code
+@return DB_SUCCESS if the fields were loaded successfully */
+static dberr_t dict_load_fields(dict_index_t *index, bool uncommitted,
+                                mem_heap_t *heap)
+{
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+
+	ut_ad(dict_sys.locked());
+
+	mtr.start();
+
+	dict_index_t* sys_index = dict_sys.sys_fields->indexes.start;
+	ut_ad(!dict_sys.sys_fields->not_redundant());
+	ut_ad(name_of_col_is(dict_sys.sys_fields, sys_index,
+			     DICT_FLD__SYS_FIELDS__COL_NAME, "COL_NAME"));
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+	byte index_id[8];
+	mach_write_to_8(index_id, index->id);
+	dfield_set_data(&dfield, index_id, 8);
+	dict_index_copy_types(&tuple, sys_index, 1);
+	pcur.btr_cur.page_cur.index = sys_index;
+
+	dberr_t error = btr_pcur_open_on_user_rec(&tuple, BTR_SEARCH_LEAF,
+						  &pcur, &mtr);
+	if (error != DB_SUCCESS) {
+		goto func_exit;
+	}
+
+	for (ulint i = 0; i < index->n_fields; i++) {
+		const char *err_msg = btr_pcur_is_on_user_rec(&pcur)
+			? dict_load_field_low(index_id, uncommitted, index,
+					      nullptr, nullptr, nullptr,
+					      heap, &mtr,
+					      btr_pcur_get_rec(&pcur))
+			: dict_load_field_none;
+
+		if (!err_msg) {
+		} else if (err_msg == dict_load_field_del) {
+			/* There could be delete marked records in
+			SYS_FIELDS because SYS_FIELDS.INDEX_ID can be
+			updated by ALTER TABLE ADD INDEX. */
+		} else {
+			if (err_msg != dict_load_field_none
+			    || strstr(index->table->name.m_name,
+				      "/" TEMP_FILE_PREFIX_INNODB)) {
+				ib::error() << err_msg << " for index "
+					    << index->name
+					    << " of table "
+					    << index->table->name;
+			}
+			error = DB_CORRUPTION;
+			break;
+		}
+
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+	}
+
+func_exit:
+	mtr.commit();
+	return error;
+}
+
+/** Error message for a delete-marked record in dict_load_index_low() */
+static const char *dict_load_index_del= "delete-marked record in SYS_INDEXES";
+/** Error message for table->id mismatch in dict_load_index_low() */
+static const char *dict_load_index_none= "SYS_INDEXES record not found";
+/** Error message for SYS_TABLES flags mismatch in dict_load_table_low() */
+static const char *dict_load_table_flags= "incorrect flags in SYS_TABLES";
+
+/** Load an index definition from a SYS_INDEXES record to dict_index_t.
+@return	error message
+@retval	NULL on success */
+static
+const char*
+dict_load_index_low(
+	byte*		table_id,	/*!< in/out: table id (8 bytes),
+					an "in" value if mtr
+					and "out" when !mtr */
+	bool		uncommitted,	/*!< in: false=READ COMMITTED,
+					true=READ UNCOMMITTED */
+	mem_heap_t*	heap,		/*!< in/out: temporary memory heap */
+	const rec_t*	rec,		/*!< in: SYS_INDEXES record */
+	mtr_t*		mtr,		/*!< in/out: mini-transaction,
+					or nullptr if a pre-allocated
+					*index is to be filled in */
+	dict_table_t*	table,		/*!< in/out: table, or NULL */
+	dict_index_t**	index)		/*!< out,own: index, or NULL */
+{
+	const byte*	field;
+	ulint		len;
+	index_id_t	id;
+	ulint		n_fields;
+	ulint		type;
+	unsigned	merge_threshold;
+
+	if (mtr) {
+		*index = NULL;
+	}
+
+	if (rec_get_n_fields_old(rec) == DICT_NUM_FIELDS__SYS_INDEXES) {
+		/* MERGE_THRESHOLD exists */
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_INDEXES__MERGE_THRESHOLD, &len);
+		switch (len) {
+		case 4:
+			merge_threshold = mach_read_from_4(field);
+			break;
+		case UNIV_SQL_NULL:
+			merge_threshold = DICT_INDEX_MERGE_THRESHOLD_DEFAULT;
+			break;
+		default:
+			return("incorrect MERGE_THRESHOLD length"
+			       " in SYS_INDEXES");
+		}
+	} else if (rec_get_n_fields_old(rec)
+		   == DICT_NUM_FIELDS__SYS_INDEXES - 1) {
+		/* MERGE_THRESHOLD doesn't exist */
+
+		merge_threshold = DICT_INDEX_MERGE_THRESHOLD_DEFAULT;
+	} else {
+		return("wrong number of columns in SYS_INDEXES record");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_INDEXES__TABLE_ID, &len);
+	if (len != 8) {
+err_len:
+		return("incorrect column length in SYS_INDEXES");
+	}
+
+	if (!mtr) {
+		/* We are reading a SYS_INDEXES record. Copy the table_id */
+		memcpy(table_id, (const char*) field, 8);
+	} else if (memcmp(field, table_id, 8)) {
+		/* Caller supplied table_id, verify it is the same
+		id as on the index record */
+		return dict_load_index_none;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_INDEXES__ID, &len);
+	if (len != 8) {
+		goto err_len;
+	}
+
+	id = mach_read_from_8(field);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_INDEXES__DB_TRX_ID, &len);
+	if (len != DATA_TRX_ID_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+	rec_get_nth_field_offs_old(
+		rec, DICT_FLD__SYS_INDEXES__DB_ROLL_PTR, &len);
+	if (len != DATA_ROLL_PTR_LEN && len != UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	const trx_id_t trx_id = trx_read_trx_id(field);
+	if (!trx_id) {
+		ut_ad(!rec_get_deleted_flag(rec, 0));
+	} else if (!mtr || uncommitted) {
+	} else if (trx_sys.find(nullptr, trx_id, false)) {
+		const auto savepoint = mtr->get_savepoint();
+		dict_index_t* sys_index = UT_LIST_GET_FIRST(
+			dict_sys.sys_indexes->indexes);
+		rec_offs* offsets = rec_get_offsets(
+			rec, sys_index, nullptr, true, ULINT_UNDEFINED, &heap);
+		const rec_t* old_vers;
+		row_vers_build_for_semi_consistent_read(
+			nullptr, rec, mtr, sys_index, &offsets, &heap,
+			heap, &old_vers, nullptr);
+		mtr->rollback_to_savepoint(savepoint);
+		rec = old_vers;
+		if (!old_vers || rec_get_deleted_flag(rec, 0)) {
+			return dict_load_index_none;
+		}
+	} else if (rec_get_deleted_flag(rec, 0)
+		   && rec[8 + 8 + DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN]
+		   != static_cast<byte>(*TEMP_INDEX_PREFIX_STR)
+		   && table->def_trx_id < trx_id) {
+		table->def_trx_id = trx_id;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_INDEXES__N_FIELDS, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	n_fields = mach_read_from_4(field);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_INDEXES__TYPE, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+	type = mach_read_from_4(field);
+	if (type & (~0U << DICT_IT_BITS)) {
+		return("unknown SYS_INDEXES.TYPE bits");
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_INDEXES__PAGE_NO, &len);
+	if (len != 4) {
+		goto err_len;
+	}
+
+	ut_d(const auto name_offs =)
+	rec_get_nth_field_offs_old(rec, DICT_FLD__SYS_INDEXES__NAME, &len);
+	ut_ad(name_offs == 8 + 8 + DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN);
+
+	if (len == 0 || len == UNIV_SQL_NULL) {
+		goto err_len;
+	}
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		return dict_load_index_del;
+	}
+
+	char* name = mem_heap_strdupl(heap, reinterpret_cast<const char*>(rec)
+				      + (8 + 8 + DATA_TRX_ID_LEN
+					 + DATA_ROLL_PTR_LEN),
+				      len);
+
+	if (mtr) {
+		*index = dict_mem_index_create(table, name, type, n_fields);
+	} else {
+		dict_mem_fill_index_struct(*index, nullptr, name,
+					   type, n_fields);
+	}
+
+	(*index)->id = id;
+	(*index)->page = mach_read_from_4(field);
+	ut_ad((*index)->page);
+	(*index)->merge_threshold = merge_threshold & ((1U << 6) - 1);
+
+	return(NULL);
+}
+
+/** Load definitions for table indexes. Adds them to the data dictionary cache.
+@param table       table definition
+@param uncommitted false=READ COMMITTED, true=READ UNCOMMITTED
+@param heap        memory heap for temporary storage
+@param ignore_err  errors to be ignored when loading the index definition
+@return error code
+@retval DB_SUCCESS if all indexes were successfully loaded
+@retval DB_CORRUPTION if corruption of dictionary table
+@retval DB_UNSUPPORTED if table has unknown index type */
+static MY_ATTRIBUTE((nonnull))
+dberr_t dict_load_indexes(dict_table_t *table, bool uncommitted,
+                          mem_heap_t *heap, dict_err_ignore_t ignore_err)
+{
+	dict_index_t*	sys_index;
+	btr_pcur_t	pcur;
+	byte		table_id[8];
+	mtr_t		mtr;
+
+	ut_ad(dict_sys.locked());
+
+	mtr.start();
+
+	sys_index = dict_sys.sys_indexes->indexes.start;
+	ut_ad(!dict_sys.sys_indexes->not_redundant());
+	ut_ad(name_of_col_is(dict_sys.sys_indexes, sys_index,
+			     DICT_FLD__SYS_INDEXES__NAME, "NAME"));
+	ut_ad(name_of_col_is(dict_sys.sys_indexes, sys_index,
+			     DICT_FLD__SYS_INDEXES__PAGE_NO, "PAGE_NO"));
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+	mach_write_to_8(table_id, table->id);
+	dfield_set_data(&dfield, table_id, 8);
+	dict_index_copy_types(&tuple, sys_index, 1);
+	pcur.btr_cur.page_cur.index = sys_index;
+
+	dberr_t error = btr_pcur_open_on_user_rec(&tuple, BTR_SEARCH_LEAF,
+						  &pcur, &mtr);
+	if (error != DB_SUCCESS) {
+		goto func_exit;
+	}
+
+	while (btr_pcur_is_on_user_rec(&pcur)) {
+		dict_index_t*	index = NULL;
+		const char*	err_msg;
+		const rec_t*	rec = btr_pcur_get_rec(&pcur);
+		if ((ignore_err & DICT_ERR_IGNORE_RECOVER_LOCK)
+		    && (rec_get_n_fields_old(rec)
+			== DICT_NUM_FIELDS__SYS_INDEXES
+			/* a record for older SYS_INDEXES table
+			(missing merge_threshold column) is acceptable. */
+			|| rec_get_n_fields_old(rec)
+			   == DICT_NUM_FIELDS__SYS_INDEXES - 1)) {
+			const byte*	field;
+			ulint		len;
+			field = rec_get_nth_field_old(
+				rec, DICT_FLD__SYS_INDEXES__NAME, &len);
+
+			if (len != UNIV_SQL_NULL
+			    && static_cast<char>(*field)
+			    == static_cast<char>(*TEMP_INDEX_PREFIX_STR)) {
+				/* Skip indexes whose name starts with
+				TEMP_INDEX_PREFIX_STR, because they will
+				be dropped by row_merge_drop_temp_indexes()
+				during crash recovery. */
+				goto next_rec;
+			}
+		}
+
+		err_msg = dict_load_index_low(table_id, uncommitted, heap, rec,
+					      &mtr, table, &index);
+		ut_ad(!index == !!err_msg);
+
+		if (err_msg == dict_load_index_none) {
+			/* We have ran out of index definitions for
+			the table. */
+			break;
+		}
+
+		if (err_msg == dict_load_index_del) {
+			goto next_rec;
+		} else if (err_msg) {
+			ib::error() << err_msg;
+			if (ignore_err & DICT_ERR_IGNORE_INDEX) {
+				goto next_rec;
+			}
+			error = DB_CORRUPTION;
+			goto func_exit;
+		} else if (rec[8 + 8 + DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN]
+			   == static_cast<byte>(*TEMP_INDEX_PREFIX_STR)) {
+			dict_mem_index_free(index);
+			goto next_rec;
+		} else {
+			const trx_id_t id = trx_read_trx_id(rec + 8 + 8);
+			if (id > table->def_trx_id) {
+				table->def_trx_id = id;
+			}
+		}
+
+		ut_ad(index);
+		ut_ad(!dict_index_is_online_ddl(index));
+
+		/* Check whether the index is corrupted */
+		if (ignore_err != DICT_ERR_IGNORE_DROP
+		    && index->is_corrupted() && index->is_clust()) {
+			dict_mem_index_free(index);
+			error = DB_TABLE_CORRUPT;
+			goto func_exit;
+		}
+
+		if (index->type & DICT_FTS
+		    && !dict_table_has_fts_index(table)) {
+			/* This should have been created by now. */
+			ut_a(table->fts != NULL);
+			DICT_TF2_FLAG_SET(table, DICT_TF2_FTS);
+		}
+
+		/* We check for unsupported types first, so that the
+		subsequent checks are relevant for the supported types. */
+		if (index->type & ~(DICT_CLUSTERED | DICT_UNIQUE
+				    | DICT_CORRUPT | DICT_FTS
+				    | DICT_SPATIAL | DICT_VIRTUAL)) {
+
+			ib::error() << "Unknown type " << index->type
+				<< " of index " << index->name
+				<< " of table " << table->name;
+
+			error = DB_UNSUPPORTED;
+			dict_mem_index_free(index);
+			goto func_exit;
+		} else if (index->page == FIL_NULL
+			   && table->is_readable()
+			   && (!(index->type & DICT_FTS))) {
+			if (!uncommitted
+			    && ignore_err != DICT_ERR_IGNORE_DROP) {
+				ib::error_or_warn(!(ignore_err
+						    & DICT_ERR_IGNORE_INDEX))
+					<< "Index " << index->name
+					<< " for table " << table->name
+					<< " has been freed!";
+			}
+
+			if (!(ignore_err & DICT_ERR_IGNORE_INDEX)) {
+corrupted:
+				dict_mem_index_free(index);
+				error = DB_CORRUPTION;
+				goto func_exit;
+			}
+			/* If caller can tolerate this error,
+			we will continue to load the index and
+			let caller deal with this error. However
+			mark the index and table corrupted. We
+			only need to mark such in the index
+			dictionary cache for such metadata corruption,
+			since we would always be able to set it
+			when loading the dictionary cache */
+			if (index->is_clust()) {
+				index->table->corrupted = true;
+				index->table->file_unreadable = true;
+			}
+			index->type |= DICT_CORRUPT;
+		} else if (!dict_index_is_clust(index)
+			   && NULL == dict_table_get_first_index(table)) {
+
+			ib::error() << "Trying to load index " << index->name
+				<< " for table " << table->name
+				<< ", but the first index is not clustered!";
+
+			goto corrupted;
+		} else if (dict_is_sys_table(table->id)
+			   && (dict_index_is_clust(index)
+			       || ((table == dict_sys.sys_tables)
+				   && !strcmp("ID_IND", index->name)))) {
+
+			/* The index was created in memory already at booting
+			of the database server */
+			dict_mem_index_free(index);
+		} else {
+			error = dict_load_fields(index, uncommitted, heap);
+			if (error != DB_SUCCESS) {
+				goto func_exit;
+			}
+
+			/* The data dictionary tables should never contain
+			invalid index definitions.  If we ignored this error
+			and simply did not load this index definition, the
+			.frm file would disagree with the index definitions
+			inside InnoDB. */
+			if ((error = dict_index_add_to_cache(index,
+							     index->page))
+			    != DB_SUCCESS) {
+				goto func_exit;
+			}
+
+#ifdef UNIV_DEBUG
+			// The following assertion doesn't hold for FTS indexes
+			// as it may have prefix_len=1 with any charset
+			if (index->type != DICT_FTS) {
+				for (uint i = 0; i < index->n_fields; i++) {
+					dict_field_t &f = index->fields[i];
+					ut_ad(f.col->mbmaxlen == 0
+					      || f.prefix_len
+					      % f.col->mbmaxlen == 0);
+				}
+			}
+#endif /* UNIV_DEBUG */
+		}
+next_rec:
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+	}
+
+	if (!dict_table_get_first_index(table)
+	    && !(ignore_err & DICT_ERR_IGNORE_INDEX)) {
+		ib::warn() << "No indexes found for table " << table->name;
+		error = DB_CORRUPTION;
+		goto func_exit;
+	}
+
+	ut_ad(table->fts_doc_id_index == NULL);
+
+	if (table->fts != NULL) {
+		dict_index_t *idx = dict_table_get_index_on_name(
+			table, FTS_DOC_ID_INDEX_NAME);
+		if (idx && dict_index_is_unique(idx)) {
+			table->fts_doc_id_index = idx;
+		}
+	}
+
+	/* If the table contains FTS indexes, populate table->fts->indexes */
+	if (dict_table_has_fts_index(table)) {
+		ut_ad(table->fts_doc_id_index != NULL);
+		/* table->fts->indexes should have been created. */
+		ut_a(table->fts->indexes != NULL);
+		dict_table_get_all_fts_indexes(table, table->fts->indexes);
+	}
+
+func_exit:
+	mtr.commit();
+	return error;
+}
+
+/** Load a table definition from a SYS_TABLES record to dict_table_t.
+Do not load any columns or indexes.
+@param[in,out]	mtr		mini-transaction
+@param[in]	uncommitted	whether to use READ UNCOMMITTED isolation level
+@param[in]	rec		SYS_TABLES record
+@param[out,own]	table		table, or nullptr
+@return	error message
+@retval	nullptr on success */
+const char *dict_load_table_low(mtr_t *mtr, bool uncommitted,
+                                const rec_t *rec, dict_table_t **table)
+{
+	table_id_t	table_id;
+	uint32_t	space_id, t_num, flags, flags2;
+	ulint		n_cols, n_v_col;
+	trx_id_t	trx_id;
+
+	if (const char* error_text = dict_sys_tables_rec_check(rec)) {
+		*table = NULL;
+		return(error_text);
+	}
+
+	if (auto r = dict_sys_tables_rec_read(rec, uncommitted, mtr,
+					      &table_id, &space_id,
+					      &t_num, &flags, &flags2,
+					      &trx_id)) {
+		*table = NULL;
+		return r == READ_ERROR ? dict_load_table_flags : nullptr;
+	}
+
+	dict_table_decode_n_col(t_num, &n_cols, &n_v_col);
+
+	*table = dict_table_t::create(
+		span<const char>(reinterpret_cast<const char*>(rec),
+				 rec_get_field_start_offs(rec, 1)),
+		nullptr, n_cols + n_v_col, n_v_col, flags, flags2);
+	(*table)->space_id = space_id;
+	(*table)->id = table_id;
+	(*table)->file_unreadable = !!(flags2 & DICT_TF2_DISCARDED);
+	(*table)->def_trx_id = trx_id;
+	return(NULL);
+}
+
+/** Make sure the data_file_name is saved in dict_table_t if needed.
+@param[in,out]	table		Table object */
+void dict_get_and_save_data_dir_path(dict_table_t *table)
+{
+  ut_ad(!table->is_temporary());
+  ut_ad(!table->space || table->space->id == table->space_id);
+
+  if (!table->data_dir_path && table->space_id && table->space)
+  {
+    const char *filepath= table->space->chain.start->name;
+    if (strncmp(fil_path_to_mysql_datadir, filepath,
+                strlen(fil_path_to_mysql_datadir)))
+    {
+      table->lock_mutex_lock();
+      table->flags|= 1 << DICT_TF_POS_DATA_DIR & ((1U << DICT_TF_BITS) - 1);
+      table->data_dir_path= mem_heap_strdup(table->heap, filepath);
+      os_file_make_data_dir_path(table->data_dir_path);
+      table->lock_mutex_unlock();
+    }
+  }
+}
+
+/** Opens a tablespace for dict_load_table_one()
+@param[in,out]	table		A table that refers to the tablespace to open
+@param[in]	ignore_err	Whether to ignore an error. */
+UNIV_INLINE
+void
+dict_load_tablespace(
+	dict_table_t*		table,
+	dict_err_ignore_t	ignore_err)
+{
+	ut_ad(!table->is_temporary());
+	ut_ad(!table->space);
+	ut_ad(table->space_id < SRV_SPACE_ID_UPPER_BOUND);
+	ut_ad(fil_system.sys_space);
+
+	if (table->space_id == TRX_SYS_SPACE) {
+		table->space = fil_system.sys_space;
+		return;
+	}
+
+	if (table->flags2 & DICT_TF2_DISCARDED) {
+		ib::warn() << "Tablespace for table " << table->name
+			<< " is set as discarded.";
+		table->file_unreadable = true;
+		return;
+	}
+
+	/* The tablespace may already be open. */
+	table->space = fil_space_for_table_exists_in_mem(table->space_id,
+							 table->flags);
+	if (table->space) {
+		return;
+	}
+
+	if (ignore_err >= DICT_ERR_IGNORE_TABLESPACE) {
+		table->file_unreadable = true;
+		return;
+	}
+
+	if (!(ignore_err & DICT_ERR_IGNORE_RECOVER_LOCK)) {
+		ib::error() << "Failed to find tablespace for table "
+			<< table->name << " in the cache. Attempting"
+			" to load the tablespace with space id "
+			<< table->space_id;
+	}
+
+	/* Use the remote filepath if needed. This parameter is optional
+	in the call to fil_ibd_open(). If not supplied, it will be built
+	from the table->name. */
+	char* filepath = NULL;
+	if (DICT_TF_HAS_DATA_DIR(table->flags)) {
+		/* This will set table->data_dir_path from fil_system */
+		dict_get_and_save_data_dir_path(table);
+
+		if (table->data_dir_path) {
+			filepath = fil_make_filepath(
+				table->data_dir_path, table->name, IBD, true);
+		}
+	}
+
+	table->space = fil_ibd_open(
+		2, FIL_TYPE_TABLESPACE, table->space_id,
+		dict_tf_to_fsp_flags(table->flags),
+		{table->name.m_name, strlen(table->name.m_name)}, filepath);
+
+	if (!table->space) {
+		/* We failed to find a sensible tablespace file */
+		table->file_unreadable = true;
+	}
+
+	ut_free(filepath);
+}
+
+/** Loads a table definition and also all its index definitions.
+
+Loads those foreign key constraints whose referenced table is already in
+dictionary cache.  If a foreign key constraint is not loaded, then the
+referenced table is pushed into the output stack (fk_tables), if it is not
+NULL.  These tables must be subsequently loaded so that all the foreign
+key constraints are loaded into memory.
+
+@param[in]	name		Table name in the db/tablename format
+@param[in]	ignore_err	Error to be ignored when loading table
+				and its index definition
+@param[out]	fk_tables	Related table names that must also be
+				loaded to ensure that all foreign key
+				constraints are loaded.
+@return table, possibly with file_unreadable flag set
+@retval nullptr if the table does not exist */
+static dict_table_t *dict_load_table_one(const span<const char> &name,
+                                         dict_err_ignore_t ignore_err,
+                                         dict_names_t &fk_tables)
+{
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+
+	DBUG_ENTER("dict_load_table_one");
+	DBUG_PRINT("dict_load_table_one",
+		   ("table: %.*s", int(name.size()), name.data()));
+
+	ut_ad(dict_sys.locked());
+
+	dict_index_t *sys_index = dict_sys.sys_tables->indexes.start;
+	ut_ad(!dict_sys.sys_tables->not_redundant());
+	ut_ad(name_of_col_is(dict_sys.sys_tables, sys_index,
+			     DICT_FLD__SYS_TABLES__ID, "ID"));
+	ut_ad(name_of_col_is(dict_sys.sys_tables, sys_index,
+			     DICT_FLD__SYS_TABLES__N_COLS, "N_COLS"));
+	ut_ad(name_of_col_is(dict_sys.sys_tables, sys_index,
+			     DICT_FLD__SYS_TABLES__TYPE, "TYPE"));
+	ut_ad(name_of_col_is(dict_sys.sys_tables, sys_index,
+			     DICT_FLD__SYS_TABLES__MIX_LEN, "MIX_LEN"));
+	ut_ad(name_of_col_is(dict_sys.sys_tables, sys_index,
+			     DICT_FLD__SYS_TABLES__SPACE, "SPACE"));
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+	dfield_set_data(&dfield, name.data(), name.size());
+	dict_index_copy_types(&tuple, sys_index, 1);
+	pcur.btr_cur.page_cur.index = sys_index;
+
+	bool uncommitted = false;
+reload:
+	mtr.start();
+	dberr_t err = btr_pcur_open_on_user_rec(&tuple,
+						BTR_SEARCH_LEAF, &pcur, &mtr);
+
+	if (err != DB_SUCCESS || !btr_pcur_is_on_user_rec(&pcur)) {
+		/* Not found */
+err_exit:
+		mtr.commit();
+		DBUG_RETURN(nullptr);
+	}
+
+	const rec_t* rec = btr_pcur_get_rec(&pcur);
+
+	/* Check if the table name in record is the searched one */
+	if (rec_get_field_start_offs(rec, 1) != name.size()
+            || memcmp(name.data(), rec, name.size())) {
+		goto err_exit;
+	}
+
+	dict_table_t* table;
+	if (const char* err_msg =
+	    dict_load_table_low(&mtr, uncommitted, rec, &table)) {
+		if (err_msg != dict_load_table_flags) {
+			ib::error() << err_msg;
+		}
+		goto err_exit;
+	}
+	if (!table) {
+		goto err_exit;
+	}
+
+        const unsigned use_uncommitted = uncommitted
+		? 2
+		: table->id == mach_read_from_8(
+			rec + rec_get_field_start_offs(
+				rec, DICT_FLD__SYS_TABLES__ID));
+
+	mtr.commit();
+
+	mem_heap_t* heap = mem_heap_create(32000);
+
+	dict_load_tablespace(table, ignore_err);
+
+	switch (dict_load_columns(table, use_uncommitted, heap)) {
+	case DB_SUCCESS_LOCKED_REC:
+		ut_ad(!uncommitted);
+		uncommitted = true;
+		dict_mem_table_free(table);
+		mem_heap_free(heap);
+		goto reload;
+	case DB_SUCCESS:
+		if (!dict_load_virtual(table, uncommitted)) {
+			break;
+		}
+		/* fall through */
+	default:
+		dict_mem_table_free(table);
+		mem_heap_free(heap);
+		DBUG_RETURN(nullptr);
+	}
+
+	dict_table_add_system_columns(table, heap);
+
+	table->can_be_evicted = true;
+	table->add_to_cache();
+
+	mem_heap_empty(heap);
+
+	ut_ad(dict_tf2_is_valid(table->flags, table->flags2));
+
+	/* If there is no tablespace for the table then we only need to
+	load the index definitions. So that we can IMPORT the tablespace
+	later. When recovering table locks for resurrected incomplete
+	transactions, the tablespace should exist, because DDL operations
+	were not allowed while the table is being locked by a transaction. */
+	dict_err_ignore_t index_load_err =
+		!(ignore_err & DICT_ERR_IGNORE_RECOVER_LOCK)
+		&& !table->is_readable()
+		? DICT_ERR_IGNORE_ALL
+		: ignore_err;
+
+	err = dict_load_indexes(table, uncommitted, heap, index_load_err);
+
+	if (err == DB_TABLE_CORRUPT) {
+		/* Refuse to load the table if the table has a corrupted
+		cluster index */
+		ut_ad(index_load_err != DICT_ERR_IGNORE_DROP);
+		ib::error() << "Refusing to load corrupted table "
+			    << table->name;
+evict:
+		dict_sys.remove(table);
+		mem_heap_free(heap);
+		DBUG_RETURN(nullptr);
+	}
+
+	if (err != DB_SUCCESS || !table->is_readable()) {
+	} else if (dict_index_t* pk = dict_table_get_first_index(table)) {
+		ut_ad(pk->is_primary());
+		if (pk->is_corrupted()
+		    || pk->page >= table->space->get_size()) {
+corrupted:
+			table->corrupted = true;
+			table->file_unreadable = true;
+			err = DB_TABLE_CORRUPT;
+		} else if (table->space->id
+			   && ignore_err == DICT_ERR_IGNORE_DROP) {
+			/* Do not bother to load data from .ibd files
+			only to delete the .ibd files. */
+			goto corrupted;
+		} else {
+			const page_id_t page_id{table->space->id, pk->page};
+			mtr.start();
+			buf_block_t* block = buf_page_get(
+				page_id, table->space->zip_size(),
+				RW_S_LATCH, &mtr);
+			const bool corrupted = !block
+				|| page_get_space_id(block->page.frame)
+				!= page_id.space()
+				|| page_get_page_no(block->page.frame)
+				!= page_id.page_no()
+				|| (mach_read_from_2(FIL_PAGE_TYPE
+						    + block->page.frame)
+				    != FIL_PAGE_INDEX
+				    && mach_read_from_2(FIL_PAGE_TYPE
+							+ block->page.frame)
+				    != FIL_PAGE_TYPE_INSTANT);
+			mtr.commit();
+			if (corrupted) {
+				goto corrupted;
+			}
+
+			if (table->supports_instant()) {
+				err = btr_cur_instant_init(table);
+			}
+		}
+	} else {
+		ut_ad(ignore_err & DICT_ERR_IGNORE_INDEX);
+		if (ignore_err != DICT_ERR_IGNORE_DROP) {
+			err = DB_CORRUPTION;
+			goto evict;
+		}
+	}
+
+	/* Initialize table foreign_child value. Its value could be
+	changed when dict_load_foreigns() is called below */
+	table->fk_max_recusive_level = 0;
+
+	/* We will load the foreign key information only if
+	all indexes were loaded. */
+	if (!table->is_readable()) {
+		/* Don't attempt to load the indexes from disk. */
+	} else if (err == DB_SUCCESS) {
+		err = dict_load_foreigns(table->name.m_name, nullptr,
+					 0, true, ignore_err, fk_tables);
+
+		if (err != DB_SUCCESS) {
+			ib::warn() << "Load table " << table->name
+				<< " failed, the table has missing"
+				" foreign key indexes. Turn off"
+				" 'foreign_key_checks' and try again.";
+			goto evict;
+		} else {
+			dict_mem_table_fill_foreign_vcol_set(table);
+			table->fk_max_recusive_level = 0;
+		}
+	}
+
+	mem_heap_free(heap);
+
+	ut_ad(!table
+	      || (ignore_err & ~DICT_ERR_IGNORE_FK_NOKEY)
+	      || !table->is_readable()
+	      || !table->corrupted);
+
+	if (table && table->fts) {
+		if (!(dict_table_has_fts_index(table)
+		      || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID)
+		      || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_ADD_DOC_ID))) {
+			/* the table->fts could be created in dict_load_column
+			when a user defined FTS_DOC_ID is present, but no
+			FTS */
+			table->fts->~fts_t();
+			table->fts = nullptr;
+		} else if (fts_optimize_wq) {
+			fts_optimize_add_table(table);
+		} else if (table->can_be_evicted) {
+			/* fts_optimize_thread is not started yet.
+			So make the table as non-evictable from cache. */
+			dict_sys.prevent_eviction(table);
+		}
+	}
+
+	ut_ad(err != DB_SUCCESS || dict_foreign_set_validate(*table));
+
+	DBUG_RETURN(table);
+}
+
+dict_table_t *dict_sys_t::load_table(const span<const char> &name,
+                                     dict_err_ignore_t ignore)
+{
+  if (dict_table_t *table= find_table(name))
+    return table;
+  dict_names_t fk_list;
+  dict_table_t *table= dict_load_table_one(name, ignore, fk_list);
+  while (!fk_list.empty())
+  {
+    const char *f= fk_list.front();
+    const span<const char> name{f, strlen(f)};
+    if (!find_table(name))
+      dict_load_table_one(name, ignore, fk_list);
+    fk_list.pop_front();
+  }
+
+  return table;
+}
+
+/***********************************************************************//**
+Loads a table object based on the table id.
+@return table; NULL if table does not exist */
+dict_table_t*
+dict_load_table_on_id(
+/*==================*/
+	table_id_t		table_id,	/*!< in: table id */
+	dict_err_ignore_t	ignore_err)	/*!< in: errors to ignore
+						when loading the table */
+{
+	byte		id_buf[8];
+	btr_pcur_t	pcur;
+	const byte*	field;
+	ulint		len;
+	mtr_t		mtr;
+
+	ut_ad(dict_sys.locked());
+
+	/* NOTE that the operation of this function is protected by
+	dict_sys.latch, and therefore no deadlocks can occur
+	with other dictionary operations. */
+
+	mtr.start();
+	/*---------------------------------------------------*/
+	/* Get the secondary index based on ID for table SYS_TABLES */
+	dict_index_t *sys_table_ids =
+		dict_sys.sys_tables->indexes.start->indexes.next;
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+
+	/* Write the table id in byte format to id_buf */
+	mach_write_to_8(id_buf, table_id);
+	dfield_set_data(&dfield, id_buf, 8);
+	dict_index_copy_types(&tuple, sys_table_ids, 1);
+	pcur.btr_cur.page_cur.index = sys_table_ids;
+
+	dict_table_t* table = nullptr;
+
+	if (btr_pcur_open_on_user_rec(&tuple, BTR_SEARCH_LEAF, &pcur, &mtr)
+	    == DB_SUCCESS
+	    && btr_pcur_is_on_user_rec(&pcur)) {
+		/*---------------------------------------------------*/
+		/* Now we have the record in the secondary index
+		containing the table ID and NAME */
+		const rec_t* rec = btr_pcur_get_rec(&pcur);
+check_rec:
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_TABLE_IDS__ID, &len);
+		ut_ad(len == 8);
+
+		/* Check if the table id in record is the one searched for */
+		if (table_id == mach_read_from_8(field)) {
+			field = rec_get_nth_field_old(rec,
+				DICT_FLD__SYS_TABLE_IDS__NAME, &len);
+			table = dict_sys.load_table(
+				{reinterpret_cast<const char*>(field),
+				 len}, ignore_err);
+			if (table && table->id != table_id) {
+				ut_ad(rec_get_deleted_flag(rec, 0));
+				table = nullptr;
+			}
+			if (!table) {
+				while (btr_pcur_move_to_next(&pcur, &mtr)) {
+					rec = btr_pcur_get_rec(&pcur);
+
+					if (page_rec_is_user_rec(rec)) {
+						goto check_rec;
+					}
+				}
+			}
+		}
+	}
+
+	mtr.commit();
+	return table;
+}
+
+/********************************************************************//**
+This function is called when the database is booted. Loads system table
+index definitions except for the clustered index which is added to the
+dictionary cache at booting before calling this function. */
+void
+dict_load_sys_table(
+/*================*/
+	dict_table_t*	table)	/*!< in: system table */
+{
+	mem_heap_t*	heap;
+
+	ut_ad(dict_sys.locked());
+
+	heap = mem_heap_create(1000);
+
+	dict_load_indexes(table, false, heap, DICT_ERR_IGNORE_NONE);
+
+	mem_heap_free(heap);
+}
+
+MY_ATTRIBUTE((nonnull, warn_unused_result))
+/********************************************************************//**
+Loads foreign key constraint col names (also for the referenced table).
+Members that must be set (and valid) in foreign:
+foreign->heap
+foreign->n_fields
+foreign->id ('\0'-terminated)
+Members that will be created and set by this function:
+foreign->foreign_col_names[i]
+foreign->referenced_col_names[i]
+(for i=0..foreign->n_fields-1) */
+static dberr_t dict_load_foreign_cols(dict_foreign_t *foreign, trx_id_t trx_id)
+{
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+	size_t		id_len;
+
+	ut_ad(dict_sys.locked());
+
+	id_len = strlen(foreign->id);
+
+	foreign->foreign_col_names = static_cast<const char**>(
+		mem_heap_alloc(foreign->heap,
+			       foreign->n_fields * sizeof(void*)));
+
+	foreign->referenced_col_names = static_cast<const char**>(
+		mem_heap_alloc(foreign->heap,
+			       foreign->n_fields * sizeof(void*)));
+
+	mtr.start();
+
+	dict_index_t* sys_index = dict_sys.sys_foreign_cols->indexes.start;
+	ut_ad(!dict_sys.sys_foreign_cols->not_redundant());
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+
+	dfield_set_data(&dfield, foreign->id, id_len);
+	dict_index_copy_types(&tuple, sys_index, 1);
+	pcur.btr_cur.page_cur.index = sys_index;
+
+	mem_heap_t* heap = nullptr;
+	dberr_t err = btr_pcur_open_on_user_rec(&tuple,
+						BTR_SEARCH_LEAF, &pcur, &mtr);
+	if (err != DB_SUCCESS) {
+		goto func_exit;
+	}
+	for (ulint i = 0; i < foreign->n_fields; i++) {
+		ut_a(btr_pcur_is_on_user_rec(&pcur));
+
+		const rec_t* rec = btr_pcur_get_rec(&pcur);
+		ulint len;
+		const byte* field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_FOREIGN_COLS__DB_TRX_ID, &len);
+		ut_a(len == DATA_TRX_ID_LEN);
+
+		if (UNIV_LIKELY_NULL(heap)) {
+			mem_heap_empty(heap);
+		}
+
+		const trx_id_t id = trx_read_trx_id(field);
+		if (!id) {
+		} else if (id != trx_id && trx_sys.find(nullptr, id, false)) {
+			const auto savepoint = mtr.get_savepoint();
+			rec_offs* offsets = rec_get_offsets(
+				rec, sys_index, nullptr, true, ULINT_UNDEFINED,
+				&heap);
+			const rec_t* old_vers;
+			row_vers_build_for_semi_consistent_read(
+				nullptr, rec, &mtr, sys_index, &offsets, &heap,
+				heap, &old_vers, nullptr);
+			mtr.rollback_to_savepoint(savepoint);
+			rec = old_vers;
+			if (!rec || rec_get_deleted_flag(rec, 0)) {
+				goto next;
+			}
+		}
+
+		if (rec_get_deleted_flag(rec, 0)) {
+			ut_ad(id);
+			goto next;
+		}
+
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_FOREIGN_COLS__ID, &len);
+
+		if (len != id_len || memcmp(foreign->id, field, len)) {
+			const rec_t*	pos;
+			ulint		pos_len;
+			const rec_t*	for_col_name;
+			ulint		for_col_name_len;
+			const rec_t*	ref_col_name;
+			ulint		ref_col_name_len;
+
+			pos = rec_get_nth_field_old(
+				rec, DICT_FLD__SYS_FOREIGN_COLS__POS,
+				&pos_len);
+
+			for_col_name = rec_get_nth_field_old(
+				rec, DICT_FLD__SYS_FOREIGN_COLS__FOR_COL_NAME,
+				&for_col_name_len);
+
+			ref_col_name = rec_get_nth_field_old(
+				rec, DICT_FLD__SYS_FOREIGN_COLS__REF_COL_NAME,
+				&ref_col_name_len);
+
+			ib::error	sout;
+
+			sout << "Unable to load column names for foreign"
+				" key '" << foreign->id
+				<< "' because it was not found in"
+				" InnoDB internal table SYS_FOREIGN_COLS. The"
+				" closest entry we found is:"
+				" (ID='";
+			sout.write(field, len);
+			sout << "', POS=" << mach_read_from_4(pos)
+				<< ", FOR_COL_NAME='";
+			sout.write(for_col_name, for_col_name_len);
+			sout << "', REF_COL_NAME='";
+			sout.write(ref_col_name, ref_col_name_len);
+			sout << "')";
+
+			err = DB_CORRUPTION;
+			break;
+		}
+
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_FOREIGN_COLS__POS, &len);
+		ut_a(len == 4);
+		ut_a(i == mach_read_from_4(field));
+
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_FOREIGN_COLS__FOR_COL_NAME, &len);
+		foreign->foreign_col_names[i] = mem_heap_strdupl(
+			foreign->heap, (char*) field, len);
+
+		field = rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_FOREIGN_COLS__REF_COL_NAME, &len);
+		foreign->referenced_col_names[i] = mem_heap_strdupl(
+			foreign->heap, (char*) field, len);
+
+next:
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+	}
+func_exit:
+	mtr.commit();
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+	return err;
+}
+
+/***********************************************************************//**
+Loads a foreign key constraint to the dictionary cache. If the referenced
+table is not yet loaded, it is added in the output parameter (fk_tables).
+@return DB_SUCCESS or error code */
+static MY_ATTRIBUTE((warn_unused_result))
+dberr_t
+dict_load_foreign(
+/*==============*/
+	const char*		table_name,	/*!< in: table name */
+	bool			uncommitted,	/*!< in: use READ UNCOMMITTED
+						transaction isolation level */
+	const char**		col_names,
+				/*!< in: column names, or NULL
+				to use foreign->foreign_table->col_names */
+	trx_id_t		trx_id,
+				/*!< in: current transaction id, or 0 */
+	bool			check_recursive,
+				/*!< in: whether to record the foreign table
+				parent count to avoid unlimited recursive
+				load of chained foreign tables */
+	bool			check_charsets,
+				/*!< in: whether to check charset
+				compatibility */
+	span<const char>	id,
+				/*!< in: foreign constraint id */
+	dict_err_ignore_t	ignore_err,
+				/*!< in: error to be ignored */
+	dict_names_t&	fk_tables)
+				/*!< out: the foreign key constraint is added
+				to the dictionary cache only if the referenced
+				table is already in cache.  Otherwise, the
+				foreign key constraint is not added to cache,
+				and the referenced table is added to this
+				stack. */
+{
+	dict_foreign_t*	foreign;
+	btr_pcur_t	pcur;
+	const byte*	field;
+	ulint		len;
+	mtr_t		mtr;
+	dict_table_t*	for_table;
+	dict_table_t*	ref_table;
+
+	DBUG_ENTER("dict_load_foreign");
+	DBUG_PRINT("dict_load_foreign",
+		   ("id: '%.*s', check_recursive: %d",
+		    int(id.size()), id.data(), check_recursive));
+
+	ut_ad(dict_sys.locked());
+
+	dict_index_t* sys_index = dict_sys.sys_foreign->indexes.start;
+	ut_ad(!dict_sys.sys_foreign->not_redundant());
+
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+	dfield_set_data(&dfield, id.data(), id.size());
+	dict_index_copy_types(&tuple, sys_index, 1);
+	pcur.btr_cur.page_cur.index = sys_index;
+
+	mtr.start();
+
+	mem_heap_t* heap = nullptr;
+	dberr_t err = btr_pcur_open_on_user_rec(&tuple,
+						BTR_SEARCH_LEAF, &pcur, &mtr);
+	if (err != DB_SUCCESS) {
+		goto err_exit;
+	}
+
+	if (!btr_pcur_is_on_user_rec(&pcur)) {
+not_found:
+		err = DB_NOT_FOUND;
+err_exit:
+		mtr.commit();
+		if (UNIV_LIKELY_NULL(heap)) {
+			mem_heap_free(heap);
+		}
+		DBUG_RETURN(err);
+	}
+
+	const rec_t* rec = btr_pcur_get_rec(&pcur);
+	static_assert(DICT_FLD__SYS_FOREIGN__ID == 0, "compatibility");
+	field = rec_get_nth_field_old(rec, DICT_FLD__SYS_FOREIGN__ID, &len);
+
+	/* Check if the id in record is the searched one */
+	if (len != id.size() || memcmp(id.data(), field, id.size())) {
+		goto not_found;
+	}
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__DB_TRX_ID, &len);
+	ut_a(len == DATA_TRX_ID_LEN);
+
+	const trx_id_t tid = trx_read_trx_id(field);
+
+	if (tid && tid != trx_id && !uncommitted
+	    && trx_sys.find(nullptr, tid, false)) {
+		const auto savepoint = mtr.get_savepoint();
+		rec_offs* offsets = rec_get_offsets(
+			rec, sys_index, nullptr, true, ULINT_UNDEFINED, &heap);
+		const rec_t* old_vers;
+		row_vers_build_for_semi_consistent_read(
+			nullptr, rec, &mtr, sys_index, &offsets, &heap,
+			heap, &old_vers, nullptr);
+		mtr.rollback_to_savepoint(savepoint);
+		rec = old_vers;
+		if (!rec) {
+			goto not_found;
+		}
+	}
+
+	if (rec_get_deleted_flag(rec, 0)) {
+		ut_ad(tid);
+		goto not_found;
+	}
+
+	/* Read the table names and the number of columns associated
+	with the constraint */
+
+	foreign = dict_mem_foreign_create();
+
+	uint32_t n_fields_and_type = mach_read_from_4(
+		rec_get_nth_field_old(
+			rec, DICT_FLD__SYS_FOREIGN__N_COLS, &len));
+
+	ut_a(len == 4);
+
+	/* We store the type in the bits 24..29 of n_fields_and_type. */
+
+	foreign->type = (n_fields_and_type >> 24) & ((1U << 6) - 1);
+	foreign->n_fields = n_fields_and_type & dict_index_t::MAX_N_FIELDS;
+
+	foreign->id = mem_heap_strdupl(foreign->heap, id.data(), id.size());
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__FOR_NAME, &len);
+
+	foreign->foreign_table_name = mem_heap_strdupl(
+		foreign->heap, (char*) field, len);
+	dict_mem_foreign_table_name_lookup_set(foreign, TRUE);
+
+	const size_t foreign_table_name_len = len;
+	const size_t table_name_len = strlen(table_name);
+
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN__REF_NAME, &len);
+
+	if (!my_charset_latin1.strnncoll(table_name, table_name_len,
+					 foreign->foreign_table_name,
+					 foreign_table_name_len)) {
+	} else if (!check_recursive
+		   && !my_charset_latin1.strnncoll(table_name, table_name_len,
+						   (const char*) field, len)) {
+	} else {
+		dict_foreign_free(foreign);
+		goto not_found;
+	}
+
+	foreign->referenced_table_name = mem_heap_strdupl(
+		foreign->heap, (const char*) field, len);
+	dict_mem_referenced_table_name_lookup_set(foreign, TRUE);
+
+	mtr.commit();
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+
+	err = dict_load_foreign_cols(foreign, trx_id);
+	if (err != DB_SUCCESS) {
+		goto load_error;
+	}
+
+	ref_table = dict_sys.find_table(
+		{foreign->referenced_table_name_lookup,
+		 strlen(foreign->referenced_table_name_lookup)});
+	for_table = dict_sys.find_table(
+		{foreign->foreign_table_name_lookup,
+		 strlen(foreign->foreign_table_name_lookup)});
+
+	if (!for_table) {
+		/* To avoid recursively loading the tables related through
+		the foreign key constraints, the child table name is saved
+		here.  The child table will be loaded later, along with its
+		foreign key constraint. */
+
+		ut_a(ref_table != NULL);
+		fk_tables.push_back(
+			mem_heap_strdupl(ref_table->heap,
+					 foreign->foreign_table_name_lookup,
+					 foreign_table_name_len));
+load_error:
+		dict_foreign_remove_from_cache(foreign);
+		DBUG_RETURN(err);
+	}
+
+	ut_a(for_table || ref_table);
+
+	/* Note that there may already be a foreign constraint object in
+	the dictionary cache for this constraint: then the following
+	call only sets the pointers in it to point to the appropriate table
+	and index objects and frees the newly created object foreign.
+	Adding to the cache should always succeed since we are not creating
+	a new foreign key constraint but loading one from the data
+	dictionary. */
+
+	DBUG_RETURN(dict_foreign_add_to_cache(foreign, col_names,
+					      check_charsets,
+					      ignore_err));
+}
+
+/***********************************************************************//**
+Loads foreign key constraints where the table is either the foreign key
+holder or where the table is referenced by a foreign key. Adds these
+constraints to the data dictionary.
+
+The foreign key constraint is loaded only if the referenced table is also
+in the dictionary cache.  If the referenced table is not in dictionary
+cache, then it is added to the output parameter (fk_tables).
+
+@return DB_SUCCESS or error code */
+dberr_t
+dict_load_foreigns(
+	const char*		table_name,	/*!< in: table name */
+	const char**		col_names,	/*!< in: column names, or NULL
+						to use table->col_names */
+	trx_id_t		trx_id,		/*!< in: DDL transaction id,
+						or 0 to check
+						recursive load of tables
+						chained by FK */
+	bool			check_charsets,	/*!< in: whether to check
+						charset compatibility */
+	dict_err_ignore_t	ignore_err,	/*!< in: error to be ignored */
+	dict_names_t&		fk_tables)
+						/*!< out: stack of table
+						names which must be loaded
+						subsequently to load all the
+						foreign key constraints. */
+{
+	btr_pcur_t	pcur;
+	mtr_t		mtr;
+
+	DBUG_ENTER("dict_load_foreigns");
+
+	ut_ad(dict_sys.locked());
+
+	if (!dict_sys.sys_foreign || !dict_sys.sys_foreign_cols) {
+		if (ignore_err & DICT_ERR_IGNORE_FK_NOKEY) {
+			DBUG_RETURN(DB_SUCCESS);
+		}
+		sql_print_information("InnoDB: No foreign key system tables"
+				      " in the database");
+		DBUG_RETURN(DB_ERROR);
+	}
+
+	ut_ad(!dict_sys.sys_foreign->not_redundant());
+
+	dict_index_t *sec_index = dict_table_get_next_index(
+		dict_table_get_first_index(dict_sys.sys_foreign));
+	ut_ad(!strcmp(sec_index->fields[0].name, "FOR_NAME"));
+	bool check_recursive = !trx_id;
+	dfield_t dfield;
+	dtuple_t tuple{
+		0,1,1,&dfield,0,nullptr
+#ifdef UNIV_DEBUG
+		, DATA_TUPLE_MAGIC_N
+#endif
+	};
+
+start_load:
+	mtr.start();
+	dfield_set_data(&dfield, table_name, strlen(table_name));
+	dict_index_copy_types(&tuple, sec_index, 1);
+	pcur.btr_cur.page_cur.index = sec_index;
+
+	dberr_t err = btr_pcur_open_on_user_rec(&tuple,
+						BTR_SEARCH_LEAF, &pcur, &mtr);
+	if (err != DB_SUCCESS) {
+		DBUG_RETURN(err);
+	}
+loop:
+	const rec_t* rec = btr_pcur_get_rec(&pcur);
+	const byte* field;
+	const auto maybe_deleted = rec_get_deleted_flag(rec, 0);
+
+	if (!btr_pcur_is_on_user_rec(&pcur)) {
+		/* End of index */
+
+		goto load_next_index;
+	}
+
+	/* Now we have the record in the secondary index containing a table
+	name and a foreign constraint ID */
+
+	ulint len;
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN_FOR_NAME__NAME, &len);
+
+	/* Check if the table name in the record is the one searched for; the
+	following call does the comparison in the latin1_swedish_ci
+	charset-collation, in a case-insensitive way. */
+
+	if (cmp_data(dfield_get_type(&dfield)->mtype,
+		     dfield_get_type(&dfield)->prtype,
+		     false,
+		     reinterpret_cast<const byte*>(table_name),
+		     dfield_get_len(&dfield),
+		     field, len)) {
+		goto load_next_index;
+	}
+
+	/* Since table names in SYS_FOREIGN are stored in a case-insensitive
+	order, we have to check that the table name matches also in a binary
+	string comparison. On Unix, MySQL allows table names that only differ
+	in character case.  If lower_case_table_names=2 then what is stored
+	may not be the same case, but the previous comparison showed that they
+	match with no-case.  */
+
+	if (lower_case_table_names != 2 && memcmp(field, table_name, len)) {
+		goto next_rec;
+	}
+
+	/* Now we get a foreign key constraint id */
+	field = rec_get_nth_field_old(
+		rec, DICT_FLD__SYS_FOREIGN_FOR_NAME__ID, &len);
+
+	/* Copy the string because the page may be modified or evicted
+	after mtr.commit() below. */
+	char	fk_id[MAX_TABLE_NAME_LEN + NAME_LEN];
+	err = DB_SUCCESS;
+	if (UNIV_LIKELY(len < sizeof fk_id)) {
+		memcpy(fk_id, field, len);
+	}
+
+	btr_pcur_store_position(&pcur, &mtr);
+
+	mtr.commit();
+
+	/* Load the foreign constraint definition to the dictionary cache */
+
+	err = len < sizeof fk_id
+		? dict_load_foreign(table_name, false, col_names, trx_id,
+				    check_recursive, check_charsets,
+				    {fk_id, len}, ignore_err, fk_tables)
+		: DB_CORRUPTION;
+
+	switch (err) {
+	case DB_SUCCESS:
+		break;
+	case DB_NOT_FOUND:
+		if (maybe_deleted) {
+			break;
+		}
+		sql_print_error("InnoDB: Cannot load foreign constraint %.*s:"
+				" could not find the relevant record in "
+				"SYS_FOREIGN", int(len), fk_id);
+		/* fall through */
+	default:
+corrupted:
+		ut_free(pcur.old_rec_buf);
+		DBUG_RETURN(err);
+	}
+
+	mtr.start();
+	if (pcur.restore_position(BTR_SEARCH_LEAF, &mtr)
+	    == btr_pcur_t::CORRUPTED) {
+		mtr.commit();
+		goto corrupted;
+	}
+next_rec:
+	btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+
+	goto loop;
+
+load_next_index:
+	mtr.commit();
+
+	if ((sec_index = dict_table_get_next_index(sec_index))) {
+		/* Switch to scan index on REF_NAME, fk_max_recusive_level
+		already been updated when scanning FOR_NAME index, no need to
+		update again */
+		check_recursive = false;
+		goto start_load;
+	}
+
+	ut_free(pcur.old_rec_buf);
+	DBUG_RETURN(DB_SUCCESS);
+}
diff --git a/storage/innobase/dict/dict0mem.cc b/storage/innobase/dict/dict0mem.cc
new file mode 100644
index 00000000..b8b2d583
--- /dev/null
+++ b/storage/innobase/dict/dict0mem.cc
@@ -0,0 +1,1379 @@
+/*****************************************************************************
+
+Copyright (c) 1996, 2018, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2013, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/******************************************************************//**
+@file dict/dict0mem.cc
+Data dictionary memory object creation
+
+Created 1/8/1996 Heikki Tuuri
+***********************************************************************/
+
+#include "ha_prototypes.h"
+#include <mysql_com.h>
+
+#include "dict0mem.h"
+#include "rem0rec.h"
+#include "data0type.h"
+#include "mach0data.h"
+#include "dict0dict.h"
+#include "fts0priv.h"
+#include "lock0lock.h"
+#include "row0row.h"
+#include "sql_string.h"
+#include <iostream>
+
+#define	DICT_HEAP_SIZE		100	/*!< initial memory heap size when
+					creating a table or index object */
+
+/** System databases */
+static const char* innobase_system_databases[] = {
+	"mysql/",
+	"information_schema/",
+	"performance_schema/",
+	NullS
+};
+
+/** Determine if a table belongs to innobase_system_databases[]
+@param[in]	name	database_name/table_name
+@return	whether the database_name is in innobase_system_databases[] */
+static bool dict_mem_table_is_system(const char *name)
+{
+	/* table has the following format: database/table
+	and some system table are of the form SYS_* */
+	if (!strchr(name, '/')) {
+		return true;
+	}
+	size_t table_len = strlen(name);
+	const char *system_db;
+	int i = 0;
+	while ((system_db = innobase_system_databases[i++])
+	       && (system_db != NullS)) {
+		size_t len = strlen(system_db);
+		if (table_len > len && !strncmp(name, system_db, len)) {
+			return true;
+		}
+	}
+	return false;
+}
+
+/** The start of the table basename suffix for partitioned tables */
+const char table_name_t::part_suffix[4]
+#ifdef _WIN32
+= "#p#";
+#else
+= "#P#";
+#endif
+
+/** Display an identifier.
+@param[in,out]	s	output stream
+@param[in]	id_name	SQL identifier (other than table name)
+@return the output stream */
+std::ostream&
+operator<<(
+	std::ostream&		s,
+	const id_name_t&	id_name)
+{
+	const char	q	= '`';
+	const char*	c	= id_name;
+	s << q;
+	for (; *c != 0; c++) {
+		if (*c == q) {
+			s << *c;
+		}
+		s << *c;
+	}
+	s << q;
+	return(s);
+}
+
+/** Display a table name.
+@param[in,out]	s		output stream
+@param[in]	table_name	table name
+@return the output stream */
+std::ostream&
+operator<<(
+	std::ostream&		s,
+	const table_name_t&	table_name)
+{
+	return(s << ut_get_name(NULL, table_name.m_name));
+}
+
+bool dict_col_t::same_encoding(uint16_t a, uint16_t b)
+{
+  if (const CHARSET_INFO *acs= get_charset(a, MYF(MY_WME)))
+    if (const CHARSET_INFO *bcs= get_charset(b, MYF(MY_WME)))
+      return Charset(bcs).encoding_allows_reinterpret_as(acs);
+  return false;
+}
+
+/** Create metadata.
+@param name     table name
+@param space    tablespace
+@param n_cols   total number of columns (both virtual and non-virtual)
+@param n_v_cols number of virtual columns
+@param flags    table flags
+@param flags2   table flags2
+@return newly allocated table object */
+dict_table_t *dict_table_t::create(const span<const char> &name,
+                                   fil_space_t *space,
+                                   ulint n_cols, ulint n_v_cols, ulint flags,
+                                   ulint flags2)
+{
+  ut_ad(!space || space->purpose == FIL_TYPE_TABLESPACE ||
+        space->purpose == FIL_TYPE_TEMPORARY ||
+        space->purpose == FIL_TYPE_IMPORT);
+  ut_a(dict_tf2_is_valid(flags, flags2));
+  ut_a(!(flags2 & DICT_TF2_UNUSED_BIT_MASK));
+
+  mem_heap_t *heap= mem_heap_create(DICT_HEAP_SIZE);
+
+  dict_table_t *table= static_cast<dict_table_t*>
+    (mem_heap_zalloc(heap, sizeof(*table)));
+
+  lock_table_lock_list_init(&table->locks);
+  UT_LIST_INIT(table->indexes, &dict_index_t::indexes);
+#ifdef BTR_CUR_HASH_ADAPT
+  UT_LIST_INIT(table->freed_indexes, &dict_index_t::indexes);
+#endif /* BTR_CUR_HASH_ADAPT */
+  table->heap= heap;
+
+  ut_d(table->magic_n= DICT_TABLE_MAGIC_N);
+
+  table->flags= static_cast<unsigned>(flags) & ((1U << DICT_TF_BITS) - 1);
+  table->flags2= static_cast<unsigned>(flags2) & ((1U << DICT_TF2_BITS) - 1);
+  table->name.m_name= mem_strdupl(name.data(), name.size());
+  table->mdl_name.m_name= table->name.m_name;
+  table->is_system_db= dict_mem_table_is_system(table->name.m_name);
+  table->space= space;
+  table->space_id= space ? space->id : UINT32_MAX;
+  table->n_t_cols= static_cast<unsigned>(n_cols + DATA_N_SYS_COLS) &
+    dict_index_t::MAX_N_FIELDS;
+  table->n_v_cols= static_cast<unsigned>(n_v_cols) &
+    dict_index_t::MAX_N_FIELDS;
+  table->n_cols= static_cast<unsigned>(table->n_t_cols - table->n_v_cols) &
+    dict_index_t::MAX_N_FIELDS;
+  table->cols= static_cast<dict_col_t*>
+    (mem_heap_alloc(heap, table->n_cols * sizeof *table->cols));
+  table->v_cols= static_cast<dict_v_col_t*>
+    (mem_heap_alloc(heap, n_v_cols * sizeof *table->v_cols));
+  for (ulint i = n_v_cols; i--; )
+    new (&table->v_cols[i]) dict_v_col_t();
+  table->autoinc_lock= static_cast<ib_lock_t*>
+    (mem_heap_alloc(heap, sizeof *table->autoinc_lock));
+  /* If the table has an FTS index or we are in the process
+  of building one, create the table->fts */
+  if (dict_table_has_fts_index(table) ||
+      DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID |
+                           DICT_TF2_FTS_ADD_DOC_ID))
+  {
+    table->fts= fts_create(table);
+    table->fts->cache= fts_cache_create(table);
+  }
+
+  new (&table->foreign_set) dict_foreign_set();
+  new (&table->referenced_set) dict_foreign_set();
+
+  return table;
+}
+
+/****************************************************************//**
+Free a table memory object. */
+void
+dict_mem_table_free(
+/*================*/
+	dict_table_t*	table)		/*!< in: table */
+{
+	ut_ad(table);
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(UT_LIST_GET_LEN(table->indexes) == 0);
+#ifdef BTR_CUR_HASH_ADAPT
+	ut_ad(UT_LIST_GET_LEN(table->freed_indexes) == 0);
+#endif /* BTR_CUR_HASH_ADAPT */
+	ut_d(table->cached = FALSE);
+
+	if (dict_table_has_fts_index(table)
+	    || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID)
+	    || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_ADD_DOC_ID)) {
+		if (table->fts) {
+			table->fts->~fts_t();
+		}
+	}
+
+	dict_mem_table_free_foreign_vcol_set(table);
+
+	table->foreign_set.~dict_foreign_set();
+	table->referenced_set.~dict_foreign_set();
+
+	ut_free(table->name.m_name);
+
+	/* Clean up virtual index info structures that are registered
+	with virtual columns */
+	for (ulint i = 0; i < table->n_v_def; i++) {
+		dict_table_get_nth_v_col(table, i)->~dict_v_col_t();
+	}
+
+	UT_DELETE(table->s_cols);
+
+	mem_heap_free(table->heap);
+}
+
+/****************************************************************//**
+Append 'name' to 'col_names'.  @see dict_table_t::col_names
+@return new column names array */
+static
+const char*
+dict_add_col_name(
+/*==============*/
+	const char*	col_names,	/*!< in: existing column names, or
+					NULL */
+	ulint		cols,		/*!< in: number of existing columns */
+	const char*	name,		/*!< in: new column name */
+	mem_heap_t*	heap)		/*!< in: heap */
+{
+	ulint	old_len;
+	ulint	new_len;
+	ulint	total_len;
+	char*	res;
+
+	ut_ad(!cols == !col_names);
+
+	/* Find out length of existing array. */
+	if (col_names) {
+		const char*	s = col_names;
+		ulint		i;
+
+		for (i = 0; i < cols; i++) {
+			s += strlen(s) + 1;
+		}
+
+		old_len = unsigned(s - col_names);
+	} else {
+		old_len = 0;
+	}
+
+	new_len = strlen(name) + 1;
+	total_len = old_len + new_len;
+
+	res = static_cast<char*>(mem_heap_alloc(heap, total_len));
+
+	if (old_len > 0) {
+		memcpy(res, col_names, old_len);
+	}
+
+	memcpy(res + old_len, name, new_len);
+
+	return(res);
+}
+
+/**********************************************************************//**
+Adds a column definition to a table. */
+void
+dict_mem_table_add_col(
+/*===================*/
+	dict_table_t*	table,	/*!< in: table */
+	mem_heap_t*	heap,	/*!< in: temporary memory heap, or NULL */
+	const char*	name,	/*!< in: column name, or NULL */
+	ulint		mtype,	/*!< in: main datatype */
+	ulint		prtype,	/*!< in: precise type */
+	ulint		len)	/*!< in: precision */
+{
+	dict_col_t*	col;
+	unsigned	i;
+
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(!heap == !name);
+
+	ut_ad(!(prtype & DATA_VIRTUAL));
+
+	i = table->n_def++;
+
+	table->n_t_def++;
+
+	if (name) {
+		if (table->n_def == table->n_cols) {
+			heap = table->heap;
+		}
+		if (i && !table->col_names) {
+			/* All preceding column names are empty. */
+			char* s = static_cast<char*>(
+				mem_heap_zalloc(heap, table->n_def));
+
+			table->col_names = s;
+		}
+
+		table->col_names = dict_add_col_name(table->col_names,
+						     i, name, heap);
+	}
+
+	col = dict_table_get_nth_col(table, i);
+
+	dict_mem_fill_column_struct(col, i, mtype, prtype, len);
+
+	switch (prtype & DATA_VERSIONED) {
+	case DATA_VERS_START:
+		ut_ad(!table->vers_start);
+		table->vers_start = i & dict_index_t::MAX_N_FIELDS;
+		break;
+	case DATA_VERS_END:
+		ut_ad(!table->vers_end);
+		table->vers_end = i & dict_index_t::MAX_N_FIELDS;
+	}
+}
+
+/** Adds a virtual column definition to a table.
+@param[in,out]	table		table
+@param[in,out]	heap		temporary memory heap, or NULL. It is
+				used to store name when we have not finished
+				adding all columns. When all columns are
+				added, the whole name will copy to memory from
+				table->heap
+@param[in]	name		column name
+@param[in]	mtype		main datatype
+@param[in]	prtype		precise type
+@param[in]	len		length
+@param[in]	pos		position in a table
+@param[in]	num_base	number of base columns
+@return the virtual column definition */
+dict_v_col_t*
+dict_mem_table_add_v_col(
+	dict_table_t*	table,
+	mem_heap_t*	heap,
+	const char*	name,
+	ulint		mtype,
+	ulint		prtype,
+	ulint		len,
+	ulint		pos,
+	ulint		num_base)
+{
+	dict_v_col_t*	v_col;
+
+	ut_ad(table);
+	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(!heap == !name);
+
+	ut_ad(prtype & DATA_VIRTUAL);
+
+	unsigned i = table->n_v_def++;
+
+	table->n_t_def++;
+
+	if (name != NULL) {
+		if (table->n_v_def == table->n_v_cols) {
+			heap = table->heap;
+		}
+
+		if (i && !table->v_col_names) {
+			/* All preceding column names are empty. */
+			char* s = static_cast<char*>(
+				mem_heap_zalloc(heap, table->n_v_def));
+
+			table->v_col_names = s;
+		}
+
+		table->v_col_names = dict_add_col_name(table->v_col_names,
+						       i, name, heap);
+	}
+
+	v_col = &table->v_cols[i];
+
+	dict_mem_fill_column_struct(&v_col->m_col, pos, mtype, prtype, len);
+	v_col->v_pos = i & dict_index_t::MAX_N_FIELDS;
+
+	if (num_base != 0) {
+		v_col->base_col = static_cast<dict_col_t**>(mem_heap_zalloc(
+					table->heap, num_base * sizeof(
+						*v_col->base_col)));
+	} else {
+		v_col->base_col = NULL;
+	}
+
+	v_col->num_base = static_cast<unsigned>(num_base)
+		& dict_index_t::MAX_N_FIELDS;
+
+	/* Initialize the index list for virtual columns */
+	ut_ad(v_col->v_indexes.empty());
+
+	return(v_col);
+}
+
+/** Adds a stored column definition to a table.
+@param[in]	table		table
+@param[in]	num_base	number of base columns. */
+void
+dict_mem_table_add_s_col(
+	dict_table_t*	table,
+	ulint		num_base)
+{
+	unsigned	i = unsigned(table->n_def) - 1;
+	dict_col_t*	col = dict_table_get_nth_col(table, i);
+	dict_s_col_t	s_col;
+
+	ut_ad(col != NULL);
+
+	if (table->s_cols == NULL) {
+		table->s_cols = UT_NEW_NOKEY(dict_s_col_list());
+	}
+
+	s_col.m_col = col;
+	s_col.s_pos = i + table->n_v_def;
+
+	if (num_base != 0) {
+		s_col.base_col = static_cast<dict_col_t**>(mem_heap_zalloc(
+			table->heap, num_base * sizeof(dict_col_t*)));
+	} else {
+		s_col.base_col = NULL;
+	}
+
+	s_col.num_base = num_base;
+	table->s_cols->push_front(s_col);
+}
+
+/**********************************************************************//**
+Renames a column of a table in the data dictionary cache. */
+static MY_ATTRIBUTE((nonnull))
+void
+dict_mem_table_col_rename_low(
+/*==========================*/
+	dict_table_t*	table,	/*!< in/out: table */
+	unsigned	i,	/*!< in: column offset corresponding to s */
+	const char*	to,	/*!< in: new column name */
+	const char*	s,	/*!< in: pointer to table->col_names */
+	bool		is_virtual)
+				/*!< in: if this is a virtual column */
+{
+	char*	t_col_names = const_cast<char*>(
+		is_virtual ? table->v_col_names : table->col_names);
+	ulint	n_col = is_virtual ? table->n_v_def : table->n_def;
+
+	size_t from_len = strlen(s), to_len = strlen(to);
+
+	ut_ad(i < table->n_def || is_virtual);
+	ut_ad(i < table->n_v_def || !is_virtual);
+
+	ut_ad(from_len <= NAME_LEN);
+	ut_ad(to_len <= NAME_LEN);
+
+	char from[NAME_LEN + 1];
+	strncpy(from, s, sizeof from - 1);
+	from[sizeof from - 1] = '\0';
+
+	if (from_len == to_len) {
+		/* The easy case: simply replace the column name in
+		table->col_names. */
+		strcpy(const_cast<char*>(s), to);
+	} else {
+		/* We need to adjust all affected index->field
+		pointers, as in dict_index_add_col(). First, copy
+		table->col_names. */
+		ulint	prefix_len	= ulint(s - t_col_names);
+
+		for (; i < n_col; i++) {
+			s += strlen(s) + 1;
+		}
+
+		ulint	full_len	= ulint(s - t_col_names);
+		char*	col_names;
+
+		if (to_len > from_len) {
+			col_names = static_cast<char*>(
+				mem_heap_alloc(
+					table->heap,
+					full_len + to_len - from_len));
+
+			memcpy(col_names, t_col_names, prefix_len);
+		} else {
+			col_names = const_cast<char*>(t_col_names);
+		}
+
+		memcpy(col_names + prefix_len, to, to_len);
+		memmove(col_names + prefix_len + to_len,
+			t_col_names + (prefix_len + from_len),
+			full_len - (prefix_len + from_len));
+
+		/* Replace the field names in every index. */
+		for (dict_index_t* index = dict_table_get_first_index(table);
+		     index != NULL;
+		     index = dict_table_get_next_index(index)) {
+			ulint	n_fields = dict_index_get_n_fields(index);
+
+			for (ulint i = 0; i < n_fields; i++) {
+				dict_field_t*	field
+					= dict_index_get_nth_field(
+						index, i);
+
+				ut_ad(!field->name
+				      == field->col->is_dropped());
+				if (!field->name) {
+					/* dropped columns lack a name */
+					ut_ad(index->is_instant());
+					continue;
+				}
+
+				/* if is_virtual and that in field->col does
+				not match, continue */
+				if ((!is_virtual) !=
+				    (!field->col->is_virtual())) {
+					continue;
+				}
+
+				ulint		name_ofs
+					= ulint(field->name - t_col_names);
+				if (name_ofs <= prefix_len) {
+					field->name = col_names + name_ofs;
+				} else {
+					ut_a(name_ofs < full_len);
+					field->name = col_names
+						+ name_ofs + to_len - from_len;
+				}
+			}
+		}
+
+		if (is_virtual) {
+			table->v_col_names = col_names;
+		} else {
+			table->col_names = col_names;
+		}
+	}
+
+	/* Virtual columns are not allowed for foreign key */
+	if (is_virtual) {
+		return;
+	}
+
+	dict_foreign_t*	foreign;
+
+	/* Replace the field names in every foreign key constraint. */
+	for (dict_foreign_set::iterator it = table->foreign_set.begin();
+	     it != table->foreign_set.end();
+	     ++it) {
+
+		foreign = *it;
+
+		if (foreign->foreign_index == NULL) {
+			/* We may go here when we set foreign_key_checks to 0,
+			and then try to rename a column and modify the
+			corresponding foreign key constraint. The index
+			would have been dropped, we have to find an equivalent
+			one */
+			for (unsigned f = 0; f < foreign->n_fields; f++) {
+				if (strcmp(foreign->foreign_col_names[f], from)
+				    == 0) {
+
+					char** rc = const_cast<char**>(
+						foreign->foreign_col_names
+						+ f);
+
+					if (to_len <= strlen(*rc)) {
+						memcpy(*rc, to, to_len + 1);
+					} else {
+						*rc = static_cast<char*>(
+							mem_heap_dup(
+								foreign->heap,
+								to,
+								to_len + 1));
+					}
+				}
+			}
+
+			/* New index can be null if InnoDB already dropped
+			the foreign index when FOREIGN_KEY_CHECKS is
+			disabled */
+			foreign->foreign_index = dict_foreign_find_index(
+				foreign->foreign_table, NULL,
+				foreign->foreign_col_names,
+				foreign->n_fields, NULL, true, false,
+				NULL, NULL, NULL);
+
+		} else {
+
+			for (unsigned f = 0; f < foreign->n_fields; f++) {
+				/* These can point straight to
+				table->col_names, because the foreign key
+				constraints will be freed at the same time
+				when the table object is freed. */
+				foreign->foreign_col_names[f]
+					= dict_index_get_nth_field(
+						foreign->foreign_index,
+						f)->name;
+			}
+		}
+	}
+
+	for (dict_foreign_set::iterator it = table->referenced_set.begin();
+	     it != table->referenced_set.end();
+	     ++it) {
+
+		foreign = *it;
+
+		if (!foreign->referenced_index) {
+			/* Referenced index could have been dropped
+			when foreign_key_checks is disabled. In that case,
+			rename the corresponding referenced_col_names and
+			find the equivalent referenced index also */
+			for (unsigned f = 0; f < foreign->n_fields; f++) {
+
+				const char*& rc =
+					foreign->referenced_col_names[f];
+				if (strcmp(rc, from)) {
+					continue;
+				}
+
+				if (to_len <= strlen(rc)) {
+					memcpy(const_cast<char*>(rc), to,
+					       to_len + 1);
+				} else {
+					rc = static_cast<char*>(
+						mem_heap_dup(
+							foreign->heap,
+							to, to_len + 1));
+				}
+			}
+
+			/* New index can be null if InnoDB already dropped
+			the referenced index when FOREIGN_KEY_CHECKS is
+			disabled */
+			foreign->referenced_index = dict_foreign_find_index(
+				foreign->referenced_table, NULL,
+				foreign->referenced_col_names,
+				foreign->n_fields, NULL, true, false,
+				NULL, NULL, NULL);
+			return;
+		}
+
+
+		for (unsigned f = 0; f < foreign->n_fields; f++) {
+			/* foreign->referenced_col_names[] need to be
+			copies, because the constraint may become
+			orphan when foreign_key_checks=0 and the
+			parent table is dropped. */
+
+			const char* col_name = dict_index_get_nth_field(
+				foreign->referenced_index, f)->name;
+
+			if (strcmp(foreign->referenced_col_names[f],
+				   col_name)) {
+				char**	rc = const_cast<char**>(
+					foreign->referenced_col_names + f);
+				size_t	col_name_len_1 = strlen(col_name) + 1;
+
+				if (col_name_len_1 <= strlen(*rc) + 1) {
+					memcpy(*rc, col_name, col_name_len_1);
+				} else {
+					*rc = static_cast<char*>(
+						mem_heap_dup(
+							foreign->heap,
+							col_name,
+							col_name_len_1));
+				}
+			}
+		}
+	}
+}
+
+/**********************************************************************//**
+Renames a column of a table in the data dictionary cache. */
+void
+dict_mem_table_col_rename(
+/*======================*/
+	dict_table_t*	table,	/*!< in/out: table */
+	ulint		nth_col,/*!< in: column index */
+	const char*	from,	/*!< in: old column name */
+	const char*	to,	/*!< in: new column name */
+	bool		is_virtual)
+				/*!< in: if this is a virtual column */
+{
+	const char*	s = is_virtual ? table->v_col_names : table->col_names;
+
+	ut_ad((!is_virtual && nth_col < table->n_def)
+	       || (is_virtual && nth_col < table->n_v_def));
+
+	for (ulint i = 0; i < nth_col; i++) {
+		size_t	len = strlen(s);
+		ut_ad(len > 0);
+		s += len + 1;
+	}
+
+	ut_ad(!my_strcasecmp(system_charset_info, from, s));
+
+	dict_mem_table_col_rename_low(table, static_cast<unsigned>(nth_col),
+				      to, s, is_virtual);
+}
+
+/**********************************************************************//**
+This function populates a dict_col_t memory structure with
+supplied information. */
+void
+dict_mem_fill_column_struct(
+/*========================*/
+	dict_col_t*	column,		/*!< out: column struct to be
+					filled */
+	ulint		col_pos,	/*!< in: column position */
+	ulint		mtype,		/*!< in: main data type */
+	ulint		prtype,		/*!< in: precise type */
+	ulint		col_len)	/*!< in: column length */
+{
+	unsigned mbminlen, mbmaxlen;
+
+	column->ind = static_cast<unsigned>(col_pos)
+		& dict_index_t::MAX_N_FIELDS;
+	column->ord_part = 0;
+	column->max_prefix = 0;
+	column->mtype = static_cast<uint8_t>(mtype);
+	column->prtype = static_cast<unsigned>(prtype);
+	column->len = static_cast<uint16_t>(col_len);
+	dtype_get_mblen(mtype, prtype, &mbminlen, &mbmaxlen);
+	column->mbminlen = mbminlen & 7;
+	column->mbmaxlen = mbmaxlen & 7;
+	column->def_val.data = NULL;
+	column->def_val.len = UNIV_SQL_DEFAULT;
+	ut_ad(!column->is_dropped());
+}
+
+/**********************************************************************//**
+Creates an index memory object.
+@return own: index object */
+dict_index_t*
+dict_mem_index_create(
+/*==================*/
+	dict_table_t*	table,		/*!< in: table */
+	const char*	index_name,	/*!< in: index name */
+	ulint		type,		/*!< in: DICT_UNIQUE,
+					DICT_CLUSTERED, ... ORed */
+	ulint		n_fields)	/*!< in: number of fields */
+{
+	dict_index_t*	index;
+	mem_heap_t*	heap;
+
+	ut_ad(!table || table->magic_n == DICT_TABLE_MAGIC_N);
+	ut_ad(index_name);
+
+	heap = mem_heap_create(DICT_HEAP_SIZE);
+
+	index = static_cast<dict_index_t*>(
+		mem_heap_zalloc(heap, sizeof(*index)));
+	index->table = table;
+
+	dict_mem_fill_index_struct(index, heap, index_name, type, n_fields);
+
+	new (&index->zip_pad.mutex) std::mutex();
+
+	if (type & DICT_SPATIAL) {
+		index->rtr_track = new
+			(mem_heap_alloc(heap, sizeof *index->rtr_track))
+			rtr_info_track_t();
+		mysql_mutex_init(rtr_active_mutex_key,
+				 &index->rtr_track->rtr_active_mutex, nullptr);
+	}
+
+	return(index);
+}
+
+/**********************************************************************//**
+Creates and initializes a foreign constraint memory object.
+@return own: foreign constraint struct */
+dict_foreign_t*
+dict_mem_foreign_create(void)
+/*=========================*/
+{
+	dict_foreign_t*	foreign;
+	mem_heap_t*	heap;
+	DBUG_ENTER("dict_mem_foreign_create");
+
+	heap = mem_heap_create(100);
+
+	foreign = static_cast<dict_foreign_t*>(
+		mem_heap_zalloc(heap, sizeof(dict_foreign_t)));
+
+	foreign->heap = heap;
+
+	foreign->v_cols = NULL;
+
+	DBUG_PRINT("dict_mem_foreign_create", ("heap: %p", heap));
+
+	DBUG_RETURN(foreign);
+}
+
+/**********************************************************************//**
+Sets the foreign_table_name_lookup pointer based on the value of
+lower_case_table_names.  If that is 0 or 1, foreign_table_name_lookup
+will point to foreign_table_name.  If 2, then another string is
+allocated from foreign->heap and set to lower case. */
+void
+dict_mem_foreign_table_name_lookup_set(
+/*===================================*/
+	dict_foreign_t*	foreign,	/*!< in/out: foreign struct */
+	ibool		do_alloc)	/*!< in: is an alloc needed */
+{
+	if (lower_case_table_names == 2) {
+		if (do_alloc) {
+			ulint	len;
+
+			len = strlen(foreign->foreign_table_name) + 1;
+
+			foreign->foreign_table_name_lookup =
+				static_cast<char*>(
+					mem_heap_alloc(foreign->heap, len));
+		}
+		strcpy(foreign->foreign_table_name_lookup,
+		       foreign->foreign_table_name);
+		innobase_casedn_str(foreign->foreign_table_name_lookup);
+	} else {
+		foreign->foreign_table_name_lookup
+			= foreign->foreign_table_name;
+	}
+}
+
+/**********************************************************************//**
+Sets the referenced_table_name_lookup pointer based on the value of
+lower_case_table_names.  If that is 0 or 1, referenced_table_name_lookup
+will point to referenced_table_name.  If 2, then another string is
+allocated from foreign->heap and set to lower case. */
+void
+dict_mem_referenced_table_name_lookup_set(
+/*======================================*/
+	dict_foreign_t*	foreign,	/*!< in/out: foreign struct */
+	ibool		do_alloc)	/*!< in: is an alloc needed */
+{
+	if (lower_case_table_names == 2) {
+		if (do_alloc) {
+			ulint	len;
+
+			len = strlen(foreign->referenced_table_name) + 1;
+
+			foreign->referenced_table_name_lookup =
+				static_cast<char*>(
+					mem_heap_alloc(foreign->heap, len));
+		}
+		strcpy(foreign->referenced_table_name_lookup,
+		       foreign->referenced_table_name);
+		innobase_casedn_str(foreign->referenced_table_name_lookup);
+	} else {
+		foreign->referenced_table_name_lookup
+			= foreign->referenced_table_name;
+	}
+}
+
+/** Fill the virtual column set with virtual column information
+present in the given virtual index.
+@param[in]	index	virtual index
+@param[out]	v_cols	virtual column set. */
+static
+void
+dict_mem_fill_vcol_has_index(
+	const dict_index_t*	index,
+	dict_vcol_set**		v_cols)
+{
+	for (ulint i = 0; i < index->table->n_v_cols; i++) {
+		dict_v_col_t*	v_col = dict_table_get_nth_v_col(
+					index->table, i);
+		if (!v_col->m_col.ord_part) {
+			continue;
+		}
+
+		for (const auto& v_idx : v_col->v_indexes) {
+			if (v_idx.index != index) {
+				continue;
+			}
+
+			if (*v_cols == NULL) {
+				*v_cols = UT_NEW_NOKEY(dict_vcol_set());
+			}
+
+			(*v_cols)->insert(v_col);
+		}
+	}
+}
+
+/** Fill the virtual column set with the virtual column of the index
+if the index contains given column name.
+@param[in]	col_name	column name
+@param[in]	table		innodb table object
+@param[out]	v_cols		set of virtual column information. */
+static
+void
+dict_mem_fill_vcol_from_v_indexes(
+	const char*		col_name,
+	const dict_table_t*	table,
+	dict_vcol_set**		v_cols)
+{
+	/* virtual column can't be Primary Key, so start with
+	secondary index */
+	for (dict_index_t* index = dict_table_get_next_index(
+			dict_table_get_first_index(table));
+		index;
+		index = dict_table_get_next_index(index)) {
+
+		/* Skip if the index have newly added
+		virtual column because field name is NULL.
+		Later virtual column set will be
+		refreshed during loading of table. */
+		if (!dict_index_has_virtual(index)
+		    || index->has_new_v_col()) {
+			continue;
+		}
+
+		for (ulint i = 0; i < index->n_fields; i++) {
+			dict_field_t*	field =
+				dict_index_get_nth_field(index, i);
+
+			if (strcmp(field->name, col_name) == 0) {
+				dict_mem_fill_vcol_has_index(
+					index, v_cols);
+			}
+		}
+	}
+}
+
+/** Fill the virtual column set with virtual columns which have base columns
+as the given col_name
+@param[in]	col_name	column name
+@param[in]	table		table object
+@param[out]	v_cols		set of virtual columns. */
+static
+void
+dict_mem_fill_vcol_set_for_base_col(
+	const char*		col_name,
+	const dict_table_t*	table,
+	dict_vcol_set**		v_cols)
+{
+	for (ulint i = 0; i < table->n_v_cols; i++) {
+		dict_v_col_t*	v_col = dict_table_get_nth_v_col(table, i);
+
+		if (!v_col->m_col.ord_part) {
+			continue;
+		}
+
+		for (ulint j = 0; j < unsigned{v_col->num_base}; j++) {
+			if (strcmp(col_name, dict_table_get_col_name(
+					table,
+					v_col->base_col[j]->ind)) == 0) {
+
+				if (*v_cols == NULL) {
+					*v_cols = UT_NEW_NOKEY(dict_vcol_set());
+				}
+
+				(*v_cols)->insert(v_col);
+			}
+		}
+	}
+}
+
+/** Fills the dependent virtual columns in a set.
+Reason for being dependent are
+1) FK can be present on base column of virtual columns
+2) FK can be present on column which is a part of virtual index
+@param[in,out]  foreign foreign key information. */
+void
+dict_mem_foreign_fill_vcol_set(
+        dict_foreign_t* foreign)
+{
+	ulint	type = foreign->type;
+
+	if (type == 0) {
+		return;
+	}
+
+	for (ulint i = 0; i < foreign->n_fields; i++) {
+		/** FK can be present on base columns
+		of virtual columns. */
+		dict_mem_fill_vcol_set_for_base_col(
+			foreign->foreign_col_names[i],
+			foreign->foreign_table,
+			&foreign->v_cols);
+
+		/** FK can be present on the columns
+		which can be a part of virtual index. */
+		dict_mem_fill_vcol_from_v_indexes(
+			foreign->foreign_col_names[i],
+			foreign->foreign_table,
+			&foreign->v_cols);
+	}
+}
+
+/** Fill virtual columns set in each fk constraint present in the table.
+@param[in,out]	table	innodb table object. */
+void
+dict_mem_table_fill_foreign_vcol_set(
+	dict_table_t*	table)
+{
+	dict_foreign_set	fk_set = table->foreign_set;
+	dict_foreign_t*		foreign;
+
+	dict_foreign_set::iterator it;
+	for (it = fk_set.begin(); it != fk_set.end(); ++it) {
+		foreign = *it;
+
+		dict_mem_foreign_fill_vcol_set(foreign);
+	}
+}
+
+/** Free the vcol_set from all foreign key constraint on the table.
+@param[in,out]	table	innodb table object. */
+void
+dict_mem_table_free_foreign_vcol_set(
+	dict_table_t*	table)
+{
+	dict_foreign_set	fk_set = table->foreign_set;
+	dict_foreign_t*		foreign;
+
+	dict_foreign_set::iterator it;
+	for (it = fk_set.begin(); it != fk_set.end(); ++it) {
+
+		foreign = *it;
+
+		if (foreign->v_cols != NULL) {
+			UT_DELETE(foreign->v_cols);
+			foreign->v_cols = NULL;
+		}
+	}
+}
+
+/**********************************************************************//**
+Frees an index memory object. */
+void
+dict_mem_index_free(
+/*================*/
+	dict_index_t*	index)	/*!< in: index */
+{
+	ut_ad(index);
+	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
+
+	index->zip_pad.mutex.~mutex();
+
+	if (dict_index_is_spatial(index)) {
+		for (auto& rtr_info : index->rtr_track->rtr_active) {
+			rtr_info->index = NULL;
+		}
+
+		mysql_mutex_destroy(&index->rtr_track->rtr_active_mutex);
+		index->rtr_track->~rtr_info_track_t();
+	}
+
+	index->detach_columns();
+	mem_heap_free(index->heap);
+}
+
+/** Create a temporary tablename like "#sql-ibNNN".
+@param[in]	heap	A memory heap
+@param[in]	dbtab	Table name in the form database/table name
+@param[in]	id	Table id
+@return A unique temporary tablename suitable for InnoDB use */
+char*
+dict_mem_create_temporary_tablename(
+	mem_heap_t*	heap,
+	const char*	dbtab,
+	table_id_t	id)
+{
+	size_t		size;
+	char*		name;
+	const char*	dbend   = strchr(dbtab, '/');
+	ut_ad(dbend);
+	size_t		dblen   = size_t(dbend - dbtab) + 1;
+
+	size = dblen + (sizeof(TEMP_FILE_PREFIX_INNODB) + 20);
+	name = static_cast<char*>(mem_heap_alloc(heap, size));
+	memcpy(name, dbtab, dblen);
+	snprintf(name + dblen, size - dblen,
+		 TEMP_FILE_PREFIX_INNODB UINT64PF, id);
+
+	return(name);
+}
+
+/** Validate the search order in the foreign key set.
+@param[in]	fk_set	the foreign key set to be validated
+@return true if search order is fine in the set, false otherwise. */
+bool
+dict_foreign_set_validate(
+	const dict_foreign_set&	fk_set)
+{
+	dict_foreign_not_exists	not_exists(fk_set);
+
+	dict_foreign_set::const_iterator it = std::find_if(
+		fk_set.begin(), fk_set.end(), not_exists);
+
+	if (it == fk_set.end()) {
+		return(true);
+	}
+
+	dict_foreign_t*	foreign = *it;
+	std::cerr << "Foreign key lookup failed: " << *foreign;
+	std::cerr << fk_set;
+	ut_ad(0);
+	return(false);
+}
+
+/** Validate the search order in the foreign key sets of the table
+(foreign_set and referenced_set).
+@param[in]	table	table whose foreign key sets are to be validated
+@return true if foreign key sets are fine, false otherwise. */
+bool
+dict_foreign_set_validate(
+	const dict_table_t&	table)
+{
+	return(dict_foreign_set_validate(table.foreign_set)
+	       && dict_foreign_set_validate(table.referenced_set));
+}
+
+std::ostream&
+operator<< (std::ostream& out, const dict_foreign_t& foreign)
+{
+	out << "[dict_foreign_t: id='" << foreign.id << "'";
+
+	if (foreign.foreign_table_name != NULL) {
+		out << ",for: '" << foreign.foreign_table_name << "'";
+	}
+
+	out << "]";
+	return(out);
+}
+
+std::ostream&
+operator<< (std::ostream& out, const dict_foreign_set& fk_set)
+{
+	out << "[dict_foreign_set:";
+	std::for_each(fk_set.begin(), fk_set.end(), dict_foreign_print(out));
+	out << "]" << std::endl;
+	return(out);
+}
+
+/** Check whether fulltext index gets affected by foreign
+key constraint. */
+bool dict_foreign_t::affects_fulltext() const
+{
+  if (foreign_table == referenced_table || !foreign_table->fts)
+    return false;
+
+  for (ulint i= 0; i < n_fields; i++)
+  {
+    const dict_col_t *col= dict_index_get_nth_col(foreign_index, i);
+    if (dict_table_is_fts_column(foreign_table->fts->indexes, col->ind,
+                                 col->is_virtual()) != ULINT_UNDEFINED)
+      return true;
+  }
+
+  return false;
+}
+
+/** Reconstruct the clustered index fields.
+@return whether metadata is incorrect */
+inline bool dict_index_t::reconstruct_fields()
+{
+	DBUG_ASSERT(is_primary());
+
+	const auto old_n_fields = n_fields;
+
+	n_fields = (n_fields + table->instant->n_dropped)
+		& dict_index_t::MAX_N_FIELDS;
+	n_def = (n_def + table->instant->n_dropped)
+		& dict_index_t::MAX_N_FIELDS;
+
+	const unsigned n_first = first_user_field();
+
+	dict_field_t* tfields = static_cast<dict_field_t*>(
+		mem_heap_zalloc(heap, n_fields * sizeof *fields));
+
+	memcpy(tfields, fields, n_first * sizeof *fields);
+
+	n_nullable = 0;
+	ulint n_core_null = 0;
+	const bool comp = dict_table_is_comp(table);
+	const auto* field_map_it = table->instant->field_map;
+	for (unsigned i = n_first, j = 0; i < n_fields; ) {
+		dict_field_t& f = tfields[i++];
+		auto c = *field_map_it++;
+		if (c.is_dropped()) {
+			f.col = &table->instant->dropped[j++];
+			DBUG_ASSERT(f.col->is_dropped());
+			f.fixed_len = dict_col_get_fixed_size(f.col, comp)
+				& ((1U << 10) - 1);
+		} else {
+			DBUG_ASSERT(!c.is_not_null());
+			const auto old = std::find_if(
+				fields + n_first, fields + old_n_fields,
+				[c](const dict_field_t& o)
+				{ return o.col->ind == c.ind(); });
+
+			if (old >= fields + old_n_fields
+			    || old->prefix_len
+			    || old->col != &table->cols[c.ind()]) {
+				return true;
+			}
+
+			ut_ad(old >= &fields[n_first]);
+			f = *old;
+		}
+
+		f.col->clear_instant();
+		if (f.col->is_nullable()) {
+			n_nullable++;
+			n_core_null += i <= n_core_fields;
+		}
+	}
+
+	fields = tfields;
+	n_core_null_bytes = static_cast<byte>(UT_BITS_IN_BYTES(n_core_null));
+
+	return false;
+}
+
+/** Reconstruct dropped or reordered columns.
+@param[in]	metadata	data from serialise_columns()
+@param[in]	len		length of the metadata, in bytes
+@return whether parsing the metadata failed */
+bool dict_table_t::deserialise_columns(const byte* metadata, ulint len)
+{
+	DBUG_ASSERT(!instant);
+
+	unsigned num_non_pk_fields = mach_read_from_4(metadata);
+	metadata += 4;
+
+	if (num_non_pk_fields >= REC_MAX_N_FIELDS - 3) {
+		return true;
+	}
+
+	dict_index_t* index = UT_LIST_GET_FIRST(indexes);
+
+	if (num_non_pk_fields < unsigned(index->n_fields)
+	    - index->first_user_field()) {
+		return true;
+	}
+
+	field_map_element_t* field_map = static_cast<field_map_element_t*>(
+		mem_heap_alloc(heap,
+			       num_non_pk_fields * sizeof *field_map));
+
+	unsigned n_dropped_cols = 0;
+
+	for (unsigned i = 0; i < num_non_pk_fields; i++) {
+		auto c = field_map[i] = mach_read_from_2(metadata);
+		metadata += 2;
+
+		if (field_map[i].is_dropped()) {
+			if (c.ind() > DICT_MAX_FIXED_COL_LEN + 1) {
+				return true;
+			}
+			n_dropped_cols++;
+		} else if (c >= n_cols) {
+			return true;
+		}
+	}
+
+	dict_col_t* dropped_cols = static_cast<dict_col_t*>(mem_heap_zalloc(
+		heap, n_dropped_cols * sizeof(dict_col_t)));
+	instant = new (mem_heap_alloc(heap, sizeof *instant)) dict_instant_t();
+	instant->n_dropped = n_dropped_cols;
+	instant->dropped = dropped_cols;
+	instant->field_map = field_map;
+
+	dict_col_t* col = dropped_cols;
+	for (unsigned i = 0; i < num_non_pk_fields; i++) {
+		if (field_map[i].is_dropped()) {
+			auto fixed_len = field_map[i].ind();
+			DBUG_ASSERT(fixed_len <= DICT_MAX_FIXED_COL_LEN + 1);
+			(col++)->set_dropped(field_map[i].is_not_null(),
+					     fixed_len == 1,
+					     fixed_len > 1 ? fixed_len - 1
+					     : 0);
+		}
+	}
+	DBUG_ASSERT(col == &dropped_cols[n_dropped_cols]);
+
+	return UT_LIST_GET_FIRST(indexes)->reconstruct_fields();
+}
+
+/** Check if record in clustered index is historical row.
+@param[in]	rec	clustered row
+@param[in]	offsets	offsets
+@return true if row is historical */
+bool
+dict_index_t::vers_history_row(
+	const rec_t*		rec,
+	const rec_offs*		offsets)
+{
+	ut_ad(is_primary());
+
+	ulint len;
+	dict_col_t& col= table->cols[table->vers_end];
+	ut_ad(col.vers_sys_end());
+	ulint nfield = dict_col_get_clust_pos(&col, this);
+	const byte *data = rec_get_nth_field(rec, offsets, nfield, &len);
+	if (col.vers_native()) {
+		ut_ad(len == sizeof trx_id_max_bytes);
+		return 0 != memcmp(data, trx_id_max_bytes, len);
+	}
+	ut_ad(len == sizeof timestamp_max_bytes);
+	return 0 != memcmp(data, timestamp_max_bytes, len);
+}
+
+/** Check if record in secondary index is historical row.
+@param[in]	rec	record in a secondary index
+@param[out]	history_row true if row is historical
+@return true on error */
+bool
+dict_index_t::vers_history_row(
+	const rec_t* rec,
+	bool &history_row)
+{
+	ut_ad(!is_primary());
+
+	/*
+	  Get row_end from clustered index
+
+	  TODO (optimization): row_end can be taken from unique secondary index
+	  as well. For that dict_index_t::vers_end member should be added and
+	  updated at index init (dict_index_build_internal_non_clust()).
+
+	  Test case:
+
+		create or replace table t1 (x int unique, y int unique,
+			foreign key r (y) references t1 (x))
+			with system versioning engine innodb;
+		insert into t1 values (1, 1);
+	 */
+	bool error = false;
+	mem_heap_t* heap = NULL;
+	dict_index_t* clust_index = NULL;
+	rec_offs offsets_[REC_OFFS_NORMAL_SIZE];
+	rec_offs* offsets = offsets_;
+	rec_offs_init(offsets_);
+
+	mtr_t mtr;
+	mtr.start();
+
+	rec_t* clust_rec =
+	    row_get_clust_rec(BTR_SEARCH_LEAF, rec, this, &clust_index, &mtr);
+	if (clust_rec) {
+		offsets = rec_get_offsets(clust_rec, clust_index, offsets,
+					  clust_index->n_core_fields,
+					  ULINT_UNDEFINED, &heap);
+
+		history_row = clust_index->vers_history_row(clust_rec, offsets);
+        } else {
+		ib::error() << "foreign constraints: secondary index is out of "
+			       "sync";
+		ut_ad("secondary index is out of sync" == 0);
+		error = true;
+	}
+	mtr.commit();
+	if (heap) {
+		mem_heap_free(heap);
+	}
+	return(error);
+}
diff --git a/storage/innobase/dict/dict0stats.cc b/storage/innobase/dict/dict0stats.cc
new file mode 100644
index 00000000..40969335
--- /dev/null
+++ b/storage/innobase/dict/dict0stats.cc
@@ -0,0 +1,4724 @@
+/*****************************************************************************
+
+Copyright (c) 2009, 2019, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2015, 2023, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file dict/dict0stats.cc
+Code used for calculating and manipulating table statistics.
+
+Created Jan 06, 2010 Vasil Dimov
+*******************************************************/
+
+#include "dict0stats.h"
+#include "dyn0buf.h"
+#include "row0sel.h"
+#include "trx0trx.h"
+#include "lock0lock.h"
+#include "pars0pars.h"
+#include <mysql_com.h>
+#include "log.h"
+#include "btr0btr.h"
+#include "que0que.h"
+#include "scope.h"
+#include "debug_sync.h"
+
+#include <algorithm>
+#include <map>
+#include <vector>
+#include <thread>
+
+/* Sampling algorithm description @{
+
+The algorithm is controlled by one number - N_SAMPLE_PAGES(index),
+let it be A, which is the number of leaf pages to analyze for a given index
+for each n-prefix (if the index is on 3 columns, then 3*A leaf pages will be
+analyzed).
+
+Let the total number of leaf pages in the table be T.
+Level 0 - leaf pages, level H - root.
+
+Definition: N-prefix-boring record is a record on a non-leaf page that equals
+the next (to the right, cross page boundaries, skipping the supremum and
+infimum) record on the same level when looking at the fist n-prefix columns.
+The last (user) record on a level is not boring (it does not match the
+non-existent user record to the right). We call the records boring because all
+the records on the page below a boring record are equal to that boring record.
+
+We avoid diving below boring records when searching for a leaf page to
+estimate the number of distinct records because we know that such a leaf
+page will have number of distinct records == 1.
+
+For each n-prefix: start from the root level and full scan subsequent lower
+levels until a level that contains at least A*10 distinct records is found.
+Lets call this level LA.
+As an optimization the search is canceled if it has reached level 1 (never
+descend to the level 0 (leaf)) and also if the next level to be scanned
+would contain more than A pages. The latter is because the user has asked
+to analyze A leaf pages and it does not make sense to scan much more than
+A non-leaf pages with the sole purpose of finding a good sample of A leaf
+pages.
+
+After finding the appropriate level LA with >A*10 distinct records (or less in
+the exceptions described above), divide it into groups of equal records and
+pick A such groups. Then pick the last record from each group. For example,
+let the level be:
+
+index:  0,1,2,3,4,5,6,7,8,9,10
+record: 1,1,1,2,2,7,7,7,7,7,9
+
+There are 4 groups of distinct records and if A=2 random ones are selected,
+e.g. 1,1,1 and 7,7,7,7,7, then records with indexes 2 and 9 will be selected.
+
+After selecting A records as described above, dive below them to find A leaf
+pages and analyze them, finding the total number of distinct records. The
+dive to the leaf level is performed by selecting a non-boring record from
+each page and diving below it.
+
+This way, a total of A leaf pages are analyzed for the given n-prefix.
+
+Let the number of different key values found in each leaf page i be Pi (i=1..A).
+Let N_DIFF_AVG_LEAF be (P1 + P2 + ... + PA) / A.
+Let the number of different key values on level LA be N_DIFF_LA.
+Let the total number of records on level LA be TOTAL_LA.
+Let R be N_DIFF_LA / TOTAL_LA, we assume this ratio is the same on the
+leaf level.
+Let the number of leaf pages be N.
+Then the total number of different key values on the leaf level is:
+N * R * N_DIFF_AVG_LEAF.
+See REF01 for the implementation.
+
+The above describes how to calculate the cardinality of an index.
+This algorithm is executed for each n-prefix of a multi-column index
+where n=1..n_uniq.
+@} */
+
+/* names of the tables from the persistent statistics storage */
+#define TABLE_STATS_NAME_PRINT	"mysql.innodb_table_stats"
+#define INDEX_STATS_NAME_PRINT	"mysql.innodb_index_stats"
+
+#ifdef UNIV_STATS_DEBUG
+#define DEBUG_PRINTF(fmt, ...)	printf(fmt, ## __VA_ARGS__)
+#else /* UNIV_STATS_DEBUG */
+#define DEBUG_PRINTF(fmt, ...)	/* noop */
+#endif /* UNIV_STATS_DEBUG */
+
+/* Gets the number of leaf pages to sample in persistent stats estimation */
+#define N_SAMPLE_PAGES(index)					\
+	static_cast<ib_uint64_t>(				\
+		(index)->table->stats_sample_pages != 0		\
+		? (index)->table->stats_sample_pages		\
+		: srv_stats_persistent_sample_pages)
+
+/* number of distinct records on a given level that are required to stop
+descending to lower levels and fetch N_SAMPLE_PAGES(index) records
+from that level */
+#define N_DIFF_REQUIRED(index)	(N_SAMPLE_PAGES(index) * 10)
+
+/* A dynamic array where we store the boundaries of each distinct group
+of keys. For example if a btree level is:
+index: 0,1,2,3,4,5,6,7,8,9,10,11,12
+data:  b,b,b,b,b,b,g,g,j,j,j, x, y
+then we would store 5,7,10,11,12 in the array. */
+typedef std::vector<ib_uint64_t, ut_allocator<ib_uint64_t> >	boundaries_t;
+
+/** Allocator type used for index_map_t. */
+typedef ut_allocator<std::pair<const char* const, dict_index_t*> >
+	index_map_t_allocator;
+
+/** Auxiliary map used for sorting indexes by name in dict_stats_save(). */
+typedef std::map<const char*, dict_index_t*, ut_strcmp_functor,
+		index_map_t_allocator>	index_map_t;
+
+bool dict_table_t::is_stats_table() const
+{
+  return !strcmp(name.m_name, TABLE_STATS_NAME) ||
+         !strcmp(name.m_name, INDEX_STATS_NAME);
+}
+
+bool trx_t::has_stats_table_lock() const
+{
+  for (const lock_t *l : lock.table_locks)
+    if (l && l->un_member.tab_lock.table->is_stats_table())
+      return true;
+  return false;
+}
+
+/*********************************************************************//**
+Checks whether an index should be ignored in stats manipulations:
+* stats fetch
+* stats recalc
+* stats save
+@return true if exists and all tables are ok */
+UNIV_INLINE
+bool
+dict_stats_should_ignore_index(
+/*===========================*/
+	const dict_index_t*	index)	/*!< in: index */
+{
+  return !index->is_btree() || index->to_be_dropped || !index->is_committed();
+}
+
+
+/** expected column definition */
+struct dict_col_meta_t
+{
+  /** column name */
+  const char *name;
+  /** main type */
+  unsigned mtype;
+  /** prtype mask; all these bits have to be set in prtype */
+  unsigned prtype_mask;
+  /** column length in bytes */
+  unsigned len;
+};
+
+/** For checking whether a table exists and has a predefined schema */
+struct dict_table_schema_t
+{
+  /** table name */
+  span<const char> table_name;
+  /** table name in SQL */
+  const char *table_name_sql;
+  /** number of columns */
+  unsigned n_cols;
+  /** columns */
+  const dict_col_meta_t columns[8];
+};
+
+static const dict_table_schema_t table_stats_schema =
+{
+  {C_STRING_WITH_LEN(TABLE_STATS_NAME)}, TABLE_STATS_NAME_PRINT, 6,
+  {
+    {"database_name", DATA_VARMYSQL, DATA_NOT_NULL, 192},
+    {"table_name", DATA_VARMYSQL, DATA_NOT_NULL, 597},
+    /*
+      Don't check the DATA_UNSIGNED flag in last_update.
+      It presents if the server is running in a pure MariaDB installation,
+      because MariaDB's Field_timestampf::flags has UNSIGNED_FLAG.
+      But DATA_UNSIGNED misses when the server starts on a MySQL-5.7 directory
+      (during a migration), because MySQL's Field_timestampf::flags does not
+      have UNSIGNED_FLAG.
+      This is fine not to check DATA_UNSIGNED, because Field_timestampf
+      in both MariaDB and MySQL support only non-negative time_t values.
+    */
+    {"last_update", DATA_INT, DATA_NOT_NULL, 4},
+    {"n_rows", DATA_INT, DATA_NOT_NULL | DATA_UNSIGNED, 8},
+    {"clustered_index_size", DATA_INT, DATA_NOT_NULL | DATA_UNSIGNED, 8},
+    {"sum_of_other_index_sizes", DATA_INT, DATA_NOT_NULL | DATA_UNSIGNED, 8},
+  }
+};
+
+static const dict_table_schema_t index_stats_schema =
+{
+  {C_STRING_WITH_LEN(INDEX_STATS_NAME)}, INDEX_STATS_NAME_PRINT, 8,
+  {
+    {"database_name", DATA_VARMYSQL, DATA_NOT_NULL, 192},
+    {"table_name", DATA_VARMYSQL, DATA_NOT_NULL, 597},
+    {"index_name", DATA_VARMYSQL, DATA_NOT_NULL, 192},
+    /*
+      Don't check the DATA_UNSIGNED flag in last_update.
+      See comments about last_update in table_stats_schema above.
+    */
+    {"last_update", DATA_INT, DATA_NOT_NULL, 4},
+    {"stat_name", DATA_VARMYSQL, DATA_NOT_NULL, 64*3},
+    {"stat_value", DATA_INT, DATA_NOT_NULL | DATA_UNSIGNED, 8},
+    {"sample_size", DATA_INT, DATA_UNSIGNED, 8},
+    {"stat_description", DATA_VARMYSQL, DATA_NOT_NULL, 1024*3}
+  }
+};
+
+/** Construct the type's SQL name (e.g. BIGINT UNSIGNED)
+@param mtype   InnoDB main type
+@param prtype  InnoDB precise type
+@param len     length of the column
+@param name    the SQL name
+@param name_sz size of the name buffer
+@return number of bytes written (excluding the terminating NUL byte) */
+static int dtype_sql_name(unsigned mtype, unsigned prtype, unsigned len,
+                          char *name, size_t name_sz)
+{
+  const char *Unsigned= "";
+  const char *Main= "UNKNOWN";
+
+  switch (mtype) {
+  case DATA_INT:
+    switch (len) {
+    case 1:
+      Main= "TINYINT";
+      break;
+    case 2:
+      Main= "SMALLINT";
+      break;
+    case 3:
+      Main= "MEDIUMINT";
+      break;
+    case 4:
+      Main= "INT";
+      break;
+    case 8:
+      Main= "BIGINT";
+      break;
+    }
+
+  append_unsigned:
+    if (prtype & DATA_UNSIGNED)
+      Unsigned= " UNSIGNED";
+    len= 0;
+    break;
+  case DATA_FLOAT:
+    Main= "FLOAT";
+    goto append_unsigned;
+  case DATA_DOUBLE:
+    Main= "DOUBLE";
+    goto append_unsigned;
+  case DATA_FIXBINARY:
+    Main= "BINARY";
+    break;
+  case DATA_CHAR:
+  case DATA_MYSQL:
+    Main= "CHAR";
+    break;
+  case DATA_VARCHAR:
+  case DATA_VARMYSQL:
+    Main= "VARCHAR";
+    break;
+  case DATA_BINARY:
+    Main= "VARBINARY";
+    break;
+  case DATA_GEOMETRY:
+    Main= "GEOMETRY";
+    len= 0;
+    break;
+  case DATA_BLOB:
+    switch (len) {
+    case 9:
+      Main= "TINYBLOB";
+      break;
+    case 10:
+      Main= "BLOB";
+      break;
+    case 11:
+      Main= "MEDIUMBLOB";
+      break;
+    case 12:
+      Main= "LONGBLOB";
+      break;
+    }
+    len= 0;
+  }
+
+  const char* Not_null= (prtype & DATA_NOT_NULL) ? " NOT NULL" : "";
+  if (len)
+    return snprintf(name, name_sz, "%s(%u)%s%s", Main, len, Unsigned,
+                    Not_null);
+  else
+    return snprintf(name, name_sz, "%s%s%s", Main, Unsigned, Not_null);
+}
+
+static bool innodb_table_stats_not_found;
+static bool innodb_index_stats_not_found;
+static bool innodb_table_stats_not_found_reported;
+static bool innodb_index_stats_not_found_reported;
+
+/*********************************************************************//**
+Checks whether a table exists and whether it has the given structure.
+The table must have the same number of columns with the same names and
+types. The order of the columns does not matter.
+dict_table_schema_check() @{
+@return DB_SUCCESS if the table exists and contains the necessary columns */
+static
+dberr_t
+dict_table_schema_check(
+/*====================*/
+	const dict_table_schema_t* req_schema,	/*!< in: required table
+						schema */
+	char*			errstr,		/*!< out: human readable error
+						message if != DB_SUCCESS is
+						returned */
+	size_t			errstr_sz)	/*!< in: errstr size */
+{
+	const dict_table_t* table= dict_sys.load_table(req_schema->table_name);
+
+	if (!table) {
+		if (opt_bootstrap)
+			return DB_TABLE_NOT_FOUND;
+		if (req_schema == &table_stats_schema) {
+			if (innodb_table_stats_not_found_reported) {
+				return DB_STATS_DO_NOT_EXIST;
+			}
+			innodb_table_stats_not_found = true;
+			innodb_table_stats_not_found_reported = true;
+		} else {
+			ut_ad(req_schema == &index_stats_schema);
+			if (innodb_index_stats_not_found_reported) {
+				return DB_STATS_DO_NOT_EXIST;
+			}
+			innodb_index_stats_not_found = true;
+			innodb_index_stats_not_found_reported = true;
+		}
+
+		snprintf(errstr, errstr_sz, "Table %s not found.",
+			 req_schema->table_name_sql);
+		return DB_TABLE_NOT_FOUND;
+	}
+
+	if (!table->is_readable() && !table->space) {
+		/* missing tablespace */
+		snprintf(errstr, errstr_sz,
+			 "Tablespace for table %s is missing.",
+			 req_schema->table_name_sql);
+		return DB_TABLE_NOT_FOUND;
+	}
+
+	if (unsigned(table->n_def - DATA_N_SYS_COLS) != req_schema->n_cols) {
+		/* the table has a different number of columns than required */
+		snprintf(errstr, errstr_sz,
+			 "%s has %d columns but should have %u.",
+			 req_schema->table_name_sql,
+			 table->n_def - DATA_N_SYS_COLS,
+			 req_schema->n_cols);
+		return DB_ERROR;
+	}
+
+	/* For each column from req_schema->columns[] search
+	whether it is present in table->cols[].
+	The following algorithm is O(n_cols^2), but is optimized to
+	be O(n_cols) if the columns are in the same order in both arrays. */
+
+	for (unsigned i = 0; i < req_schema->n_cols; i++) {
+		ulint	j = dict_table_has_column(
+			table, req_schema->columns[i].name, i);
+
+		if (j == table->n_def) {
+			snprintf(errstr, errstr_sz,
+				    "required column %s"
+				    " not found in table %s.",
+				    req_schema->columns[i].name,
+				    req_schema->table_name_sql);
+
+			return(DB_ERROR);
+		}
+
+		/* we found a column with the same name on j'th position,
+		compare column types and flags */
+
+		/* check length for exact match */
+		if (req_schema->columns[i].len != table->cols[j].len) {
+			sql_print_warning("InnoDB: Table %s has"
+					  " length mismatch in the"
+					  " column name %s."
+					  " Please run mariadb-upgrade",
+					  req_schema->table_name_sql,
+					  req_schema->columns[i].name);
+		}
+
+		/*
+                  check mtype for exact match.
+                  This check is relaxed to allow use to use TIMESTAMP
+                  (ie INT) for last_update instead of DATA_BINARY.
+                  We have to test for both values as the innodb_table_stats
+                  table may come from MySQL and have the old type.
+                */
+		if (req_schema->columns[i].mtype != table->cols[j].mtype &&
+                    !(req_schema->columns[i].mtype == DATA_INT &&
+                      table->cols[j].mtype == DATA_FIXBINARY)) {
+		} else if ((~table->cols[j].prtype
+			    & req_schema->columns[i].prtype_mask)) {
+		} else {
+			continue;
+		}
+
+		int s = snprintf(errstr, errstr_sz,
+				 "Column %s in table %s is ",
+				 req_schema->columns[i].name,
+				 req_schema->table_name_sql);
+		if (s < 0 || static_cast<size_t>(s) >= errstr_sz) {
+			return DB_ERROR;
+		}
+		errstr += s;
+		errstr_sz -= s;
+		s = dtype_sql_name(table->cols[j].mtype, table->cols[j].prtype,
+				   table->cols[j].len, errstr, errstr_sz);
+		if (s < 0 || static_cast<size_t>(s) + sizeof " but should be "
+		    >= errstr_sz) {
+			return DB_ERROR;
+		}
+		errstr += s;
+		memcpy(errstr, " but should be ", sizeof " but should be ");
+		errstr += (sizeof " but should be ") - 1;
+		errstr_sz -= s + (sizeof " but should be ") - 1;
+		s = dtype_sql_name(req_schema->columns[i].mtype,
+				   req_schema->columns[i].prtype_mask,
+				   req_schema->columns[i].len,
+				   errstr, errstr_sz);
+		return DB_ERROR;
+	}
+
+	if (size_t n_foreign = table->foreign_set.size()) {
+		snprintf(errstr, errstr_sz,
+			 "Table %s has %zu foreign key(s) pointing"
+			 " to other tables, but it must have 0.",
+			 req_schema->table_name_sql, n_foreign);
+		return DB_ERROR;
+	}
+
+	if (size_t n_referenced = table->referenced_set.size()) {
+		snprintf(errstr, errstr_sz,
+			 "There are %zu foreign key(s) pointing to %s, "
+			 "but there must be 0.", n_referenced,
+			 req_schema->table_name_sql);
+		return DB_ERROR;
+	}
+
+	return DB_SUCCESS;
+}
+
+/*********************************************************************//**
+Checks whether the persistent statistics storage exists and that all
+tables have the proper structure.
+@return true if exists and all tables are ok */
+static bool dict_stats_persistent_storage_check(bool dict_already_locked)
+{
+	char		errstr[512];
+	dberr_t		ret;
+
+	if (!dict_already_locked) {
+		dict_sys.lock(SRW_LOCK_CALL);
+	}
+
+	ut_ad(dict_sys.locked());
+
+	/* first check table_stats */
+	ret = dict_table_schema_check(&table_stats_schema, errstr,
+				      sizeof(errstr));
+	if (ret == DB_SUCCESS) {
+		/* if it is ok, then check index_stats */
+		ret = dict_table_schema_check(&index_stats_schema, errstr,
+					      sizeof(errstr));
+	}
+
+	if (!dict_already_locked) {
+		dict_sys.unlock();
+	}
+
+	switch (ret) {
+	case DB_SUCCESS:
+		return true;
+	default:
+		if (!opt_bootstrap) {
+			ib::error() << errstr;
+		}
+		/* fall through */
+	case DB_STATS_DO_NOT_EXIST:
+		return false;
+	}
+}
+
+/** Executes a given SQL statement using the InnoDB internal SQL parser.
+This function will free the pinfo object.
+@param[in,out]	pinfo	pinfo to pass to que_eval_sql() must already
+have any literals bound to it
+@param[in]	sql	SQL string to execute
+@param[in,out]	trx	transaction
+@return DB_SUCCESS or error code */
+static
+dberr_t dict_stats_exec_sql(pars_info_t *pinfo, const char* sql, trx_t *trx)
+{
+  ut_ad(dict_sys.locked());
+
+  if (!dict_stats_persistent_storage_check(true))
+  {
+    pars_info_free(pinfo);
+    return DB_STATS_DO_NOT_EXIST;
+  }
+
+  return que_eval_sql(pinfo, sql, trx);
+}
+
+/*********************************************************************//**
+Duplicate a table object and its indexes.
+This function creates a dummy dict_table_t object and initializes the
+following table and index members:
+dict_table_t::id (copied)
+dict_table_t::heap (newly created)
+dict_table_t::name (copied)
+dict_table_t::corrupted (copied)
+dict_table_t::indexes<> (newly created)
+dict_table_t::magic_n
+for each entry in dict_table_t::indexes, the following are initialized:
+(indexes that have DICT_FTS set in index->type are skipped)
+dict_index_t::id (copied)
+dict_index_t::name (copied)
+dict_index_t::table_name (points to the copied table name)
+dict_index_t::table (points to the above semi-initialized object)
+dict_index_t::type (copied)
+dict_index_t::to_be_dropped (copied)
+dict_index_t::online_status (copied)
+dict_index_t::n_uniq (copied)
+dict_index_t::fields[] (newly created, only first n_uniq, only fields[i].name)
+dict_index_t::indexes<> (newly created)
+dict_index_t::stat_n_diff_key_vals[] (only allocated, left uninitialized)
+dict_index_t::stat_n_sample_sizes[] (only allocated, left uninitialized)
+dict_index_t::stat_n_non_null_key_vals[] (only allocated, left uninitialized)
+dict_index_t::magic_n
+The returned object should be freed with dict_stats_table_clone_free()
+when no longer needed.
+@return incomplete table object */
+static
+dict_table_t*
+dict_stats_table_clone_create(
+/*==========================*/
+	const dict_table_t*	table)	/*!< in: table whose stats to copy */
+{
+	size_t		heap_size;
+	dict_index_t*	index;
+
+	/* Estimate the size needed for the table and all of its indexes */
+
+	heap_size = 0;
+	heap_size += sizeof(dict_table_t);
+	heap_size += strlen(table->name.m_name) + 1;
+
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		if (dict_stats_should_ignore_index(index)) {
+			continue;
+		}
+
+		ut_ad(!dict_index_is_ibuf(index));
+
+		ulint	n_uniq = dict_index_get_n_unique(index);
+
+		heap_size += sizeof(dict_index_t);
+		heap_size += strlen(index->name) + 1;
+		heap_size += n_uniq * sizeof(index->fields[0]);
+		for (ulint i = 0; i < n_uniq; i++) {
+			heap_size += strlen(index->fields[i].name) + 1;
+		}
+		heap_size += n_uniq * sizeof(index->stat_n_diff_key_vals[0]);
+		heap_size += n_uniq * sizeof(index->stat_n_sample_sizes[0]);
+		heap_size += n_uniq * sizeof(index->stat_n_non_null_key_vals[0]);
+	}
+
+	/* Allocate the memory and copy the members */
+
+	mem_heap_t*	heap;
+
+	heap = mem_heap_create(heap_size);
+
+	dict_table_t*	t;
+
+	t = (dict_table_t*) mem_heap_zalloc(heap, sizeof(*t));
+
+	t->stats_mutex_init();
+
+	MEM_CHECK_DEFINED(&table->id, sizeof(table->id));
+	t->id = table->id;
+
+	t->heap = heap;
+
+	t->name.m_name = mem_heap_strdup(heap, table->name.m_name);
+	t->mdl_name.m_name = t->name.m_name;
+
+	t->corrupted = table->corrupted;
+
+	UT_LIST_INIT(t->indexes, &dict_index_t::indexes);
+#ifdef BTR_CUR_HASH_ADAPT
+	UT_LIST_INIT(t->freed_indexes, &dict_index_t::indexes);
+#endif /* BTR_CUR_HASH_ADAPT */
+
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		if (dict_stats_should_ignore_index(index)) {
+			continue;
+		}
+
+		ut_ad(!dict_index_is_ibuf(index));
+
+		dict_index_t*	idx;
+
+		idx = (dict_index_t*) mem_heap_zalloc(heap, sizeof(*idx));
+
+		MEM_CHECK_DEFINED(&index->id, sizeof(index->id));
+		idx->id = index->id;
+
+		idx->name = mem_heap_strdup(heap, index->name);
+
+		idx->table = t;
+
+		idx->type = index->type;
+
+		idx->to_be_dropped = 0;
+
+		idx->online_status = ONLINE_INDEX_COMPLETE;
+		idx->set_committed(true);
+
+		idx->n_uniq = index->n_uniq;
+
+		idx->fields = (dict_field_t*) mem_heap_zalloc(
+			heap, idx->n_uniq * sizeof(idx->fields[0]));
+
+		for (ulint i = 0; i < idx->n_uniq; i++) {
+			idx->fields[i].name = mem_heap_strdup(
+				heap, index->fields[i].name);
+		}
+
+		/* hook idx into t->indexes */
+		UT_LIST_ADD_LAST(t->indexes, idx);
+
+		idx->stat_n_diff_key_vals = (ib_uint64_t*) mem_heap_zalloc(
+			heap,
+			idx->n_uniq * sizeof(idx->stat_n_diff_key_vals[0]));
+
+		idx->stat_n_sample_sizes = (ib_uint64_t*) mem_heap_zalloc(
+			heap,
+			idx->n_uniq * sizeof(idx->stat_n_sample_sizes[0]));
+
+		idx->stat_n_non_null_key_vals = (ib_uint64_t*) mem_heap_zalloc(
+			heap,
+			idx->n_uniq * sizeof(idx->stat_n_non_null_key_vals[0]));
+		ut_d(idx->magic_n = DICT_INDEX_MAGIC_N);
+
+		idx->stat_defrag_n_page_split = 0;
+		idx->stat_defrag_n_pages_freed = 0;
+	}
+
+	ut_d(t->magic_n = DICT_TABLE_MAGIC_N);
+
+	return(t);
+}
+
+/*********************************************************************//**
+Free the resources occupied by an object returned by
+dict_stats_table_clone_create(). */
+static
+void
+dict_stats_table_clone_free(
+/*========================*/
+	dict_table_t*	t)	/*!< in: dummy table object to free */
+{
+	t->stats_mutex_destroy();
+	mem_heap_free(t->heap);
+}
+
+/*********************************************************************//**
+Write all zeros (or 1 where it makes sense) into an index
+statistics members. The resulting stats correspond to an empty index. */
+static
+void
+dict_stats_empty_index(
+/*===================*/
+	dict_index_t*	index,	/*!< in/out: index */
+	bool		empty_defrag_stats)
+				/*!< in: whether to empty defrag stats */
+{
+	ut_ad(!(index->type & DICT_FTS));
+	ut_ad(!dict_index_is_ibuf(index));
+	ut_ad(index->table->stats_mutex_is_owner());
+
+	ulint	n_uniq = index->n_uniq;
+
+	for (ulint i = 0; i < n_uniq; i++) {
+		index->stat_n_diff_key_vals[i] = 0;
+		index->stat_n_sample_sizes[i] = 1;
+		index->stat_n_non_null_key_vals[i] = 0;
+	}
+
+	index->stat_index_size = 1;
+	index->stat_n_leaf_pages = 1;
+
+	if (empty_defrag_stats) {
+		dict_stats_empty_defrag_stats(index);
+		dict_stats_empty_defrag_summary(index);
+	}
+}
+
+/*********************************************************************//**
+Write all zeros (or 1 where it makes sense) into a table and its indexes'
+statistics members. The resulting stats correspond to an empty table. */
+static
+void
+dict_stats_empty_table(
+/*===================*/
+	dict_table_t*	table,	/*!< in/out: table */
+	bool		empty_defrag_stats)
+				/*!< in: whether to empty defrag stats */
+{
+	/* Initialize table/index level stats is now protected by
+	table level lock_mutex.*/
+	table->stats_mutex_lock();
+
+	/* Zero the stats members */
+	table->stat_n_rows = 0;
+	table->stat_clustered_index_size = 1;
+	/* 1 page for each index, not counting the clustered */
+	table->stat_sum_of_other_index_sizes
+		= UT_LIST_GET_LEN(table->indexes) - 1;
+	table->stat_modified_counter = 0;
+
+	dict_index_t*	index;
+
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		if (index->type & DICT_FTS) {
+			continue;
+		}
+
+		ut_ad(!dict_index_is_ibuf(index));
+
+		dict_stats_empty_index(index, empty_defrag_stats);
+	}
+
+	table->stat_initialized = TRUE;
+	table->stats_mutex_unlock();
+}
+
+/*********************************************************************//**
+Check whether index's stats are initialized (assert if they are not). */
+static
+void
+dict_stats_assert_initialized_index(
+/*================================*/
+	const dict_index_t*	index)	/*!< in: index */
+{
+	MEM_CHECK_DEFINED(
+		index->stat_n_diff_key_vals,
+		index->n_uniq * sizeof(index->stat_n_diff_key_vals[0]));
+
+	MEM_CHECK_DEFINED(
+		index->stat_n_sample_sizes,
+		index->n_uniq * sizeof(index->stat_n_sample_sizes[0]));
+
+	MEM_CHECK_DEFINED(
+		index->stat_n_non_null_key_vals,
+		index->n_uniq * sizeof(index->stat_n_non_null_key_vals[0]));
+
+	MEM_CHECK_DEFINED(
+		&index->stat_index_size,
+		sizeof(index->stat_index_size));
+
+	MEM_CHECK_DEFINED(
+		&index->stat_n_leaf_pages,
+		sizeof(index->stat_n_leaf_pages));
+}
+
+/*********************************************************************//**
+Check whether table's stats are initialized (assert if they are not). */
+static
+void
+dict_stats_assert_initialized(
+/*==========================*/
+	const dict_table_t*	table)	/*!< in: table */
+{
+	ut_a(table->stat_initialized);
+
+	MEM_CHECK_DEFINED(&table->stats_last_recalc,
+			  sizeof table->stats_last_recalc);
+
+	MEM_CHECK_DEFINED(&table->stat_persistent,
+			  sizeof table->stat_persistent);
+
+	MEM_CHECK_DEFINED(&table->stats_auto_recalc,
+			  sizeof table->stats_auto_recalc);
+
+	MEM_CHECK_DEFINED(&table->stats_sample_pages,
+			  sizeof table->stats_sample_pages);
+
+	MEM_CHECK_DEFINED(&table->stat_n_rows,
+			  sizeof table->stat_n_rows);
+
+	MEM_CHECK_DEFINED(&table->stat_clustered_index_size,
+			  sizeof table->stat_clustered_index_size);
+
+	MEM_CHECK_DEFINED(&table->stat_sum_of_other_index_sizes,
+			  sizeof table->stat_sum_of_other_index_sizes);
+
+	MEM_CHECK_DEFINED(&table->stat_modified_counter,
+			  sizeof table->stat_modified_counter);
+
+	for (dict_index_t* index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		if (!dict_stats_should_ignore_index(index)) {
+			dict_stats_assert_initialized_index(index);
+		}
+	}
+}
+
+#define INDEX_EQ(i1, i2) \
+	((i1) != NULL \
+	 && (i2) != NULL \
+	 && (i1)->id == (i2)->id \
+	 && strcmp((i1)->name, (i2)->name) == 0)
+
+/*********************************************************************//**
+Copy table and index statistics from one table to another, including index
+stats. Extra indexes in src are ignored and extra indexes in dst are
+initialized to correspond to an empty index. */
+static
+void
+dict_stats_copy(
+/*============*/
+	dict_table_t*		dst,	/*!< in/out: destination table */
+	const dict_table_t*	src,	/*!< in: source table */
+	bool reset_ignored_indexes)	/*!< in: if true, set ignored indexes
+                                             to have the same statistics as if
+                                             the table was empty */
+{
+	ut_ad(src->stats_mutex_is_owner());
+	ut_ad(dst->stats_mutex_is_owner());
+
+	dst->stats_last_recalc = src->stats_last_recalc;
+	dst->stat_n_rows = src->stat_n_rows;
+	dst->stat_clustered_index_size = src->stat_clustered_index_size;
+	dst->stat_sum_of_other_index_sizes = src->stat_sum_of_other_index_sizes;
+	dst->stat_modified_counter = src->stat_modified_counter;
+
+	dict_index_t*	dst_idx;
+	dict_index_t*	src_idx;
+
+	for (dst_idx = dict_table_get_first_index(dst),
+	     src_idx = dict_table_get_first_index(src);
+	     dst_idx != NULL;
+	     dst_idx = dict_table_get_next_index(dst_idx),
+	     (src_idx != NULL
+	      && (src_idx = dict_table_get_next_index(src_idx)))) {
+
+		if (dict_stats_should_ignore_index(dst_idx)) {
+			if (reset_ignored_indexes) {
+				/* Reset index statistics for all ignored indexes,
+				unless they are FT indexes (these have no statistics)*/
+				if (dst_idx->type & DICT_FTS) {
+					continue;
+				}
+				dict_stats_empty_index(dst_idx, true);
+			} else {
+				continue;
+			}
+		}
+
+		ut_ad(!dict_index_is_ibuf(dst_idx));
+
+		if (!INDEX_EQ(src_idx, dst_idx)) {
+			for (src_idx = dict_table_get_first_index(src);
+			     src_idx != NULL;
+			     src_idx = dict_table_get_next_index(src_idx)) {
+
+				if (INDEX_EQ(src_idx, dst_idx)) {
+					break;
+				}
+			}
+		}
+
+		if (!INDEX_EQ(src_idx, dst_idx)) {
+			dict_stats_empty_index(dst_idx, true);
+			continue;
+		}
+
+		ulint	n_copy_el;
+
+		if (dst_idx->n_uniq > src_idx->n_uniq) {
+			n_copy_el = src_idx->n_uniq;
+			/* Since src is smaller some elements in dst
+			will remain untouched by the following memmove(),
+			thus we init all of them here. */
+			dict_stats_empty_index(dst_idx, true);
+		} else {
+			n_copy_el = dst_idx->n_uniq;
+		}
+
+		memmove(dst_idx->stat_n_diff_key_vals,
+			src_idx->stat_n_diff_key_vals,
+			n_copy_el * sizeof(dst_idx->stat_n_diff_key_vals[0]));
+
+		memmove(dst_idx->stat_n_sample_sizes,
+			src_idx->stat_n_sample_sizes,
+			n_copy_el * sizeof(dst_idx->stat_n_sample_sizes[0]));
+
+		memmove(dst_idx->stat_n_non_null_key_vals,
+			src_idx->stat_n_non_null_key_vals,
+			n_copy_el * sizeof(dst_idx->stat_n_non_null_key_vals[0]));
+
+		dst_idx->stat_index_size = src_idx->stat_index_size;
+
+		dst_idx->stat_n_leaf_pages = src_idx->stat_n_leaf_pages;
+
+		dst_idx->stat_defrag_modified_counter =
+			src_idx->stat_defrag_modified_counter;
+		dst_idx->stat_defrag_n_pages_freed =
+			src_idx->stat_defrag_n_pages_freed;
+		dst_idx->stat_defrag_n_page_split =
+			src_idx->stat_defrag_n_page_split;
+	}
+
+	dst->stat_initialized = TRUE;
+}
+
+/** Duplicate the stats of a table and its indexes.
+This function creates a dummy dict_table_t object and copies the input
+table's stats into it. The returned table object is not in the dictionary
+cache and cannot be accessed by any other threads. In addition to the
+members copied in dict_stats_table_clone_create() this function initializes
+the following:
+dict_table_t::stat_initialized
+dict_table_t::stat_persistent
+dict_table_t::stat_n_rows
+dict_table_t::stat_clustered_index_size
+dict_table_t::stat_sum_of_other_index_sizes
+dict_table_t::stat_modified_counter
+dict_index_t::stat_n_diff_key_vals[]
+dict_index_t::stat_n_sample_sizes[]
+dict_index_t::stat_n_non_null_key_vals[]
+dict_index_t::stat_index_size
+dict_index_t::stat_n_leaf_pages
+dict_index_t::stat_defrag_modified_counter
+dict_index_t::stat_defrag_n_pages_freed
+dict_index_t::stat_defrag_n_page_split
+The returned object should be freed with dict_stats_snapshot_free()
+when no longer needed.
+@param[in]	table	table whose stats to copy
+@return incomplete table object */
+static
+dict_table_t*
+dict_stats_snapshot_create(
+	dict_table_t*	table)
+{
+	dict_sys.lock(SRW_LOCK_CALL);
+
+	dict_stats_assert_initialized(table);
+
+	dict_table_t*	t;
+
+	t = dict_stats_table_clone_create(table);
+
+	table->stats_mutex_lock();
+	ut_d(t->stats_mutex_lock());
+
+	dict_stats_copy(t, table, false);
+
+	ut_d(t->stats_mutex_unlock());
+	table->stats_mutex_unlock();
+
+	t->stat_persistent = table->stat_persistent;
+	t->stats_auto_recalc = table->stats_auto_recalc;
+	t->stats_sample_pages = table->stats_sample_pages;
+
+	dict_sys.unlock();
+
+	return(t);
+}
+
+/*********************************************************************//**
+Free the resources occupied by an object returned by
+dict_stats_snapshot_create(). */
+static
+void
+dict_stats_snapshot_free(
+/*=====================*/
+	dict_table_t*	t)	/*!< in: dummy table object to free */
+{
+	dict_stats_table_clone_free(t);
+}
+
+/** Statistics for one field of an index. */
+struct index_field_stats_t
+{
+  ib_uint64_t n_diff_key_vals;
+  ib_uint64_t n_sample_sizes;
+  ib_uint64_t n_non_null_key_vals;
+
+  index_field_stats_t(ib_uint64_t n_diff_key_vals= 0,
+                      ib_uint64_t n_sample_sizes= 0,
+                      ib_uint64_t n_non_null_key_vals= 0)
+      : n_diff_key_vals(n_diff_key_vals), n_sample_sizes(n_sample_sizes),
+        n_non_null_key_vals(n_non_null_key_vals)
+  {
+  }
+
+  bool is_bulk_operation() const
+  {
+    return n_diff_key_vals == UINT64_MAX &&
+      n_sample_sizes == UINT64_MAX && n_non_null_key_vals == UINT64_MAX;
+  }
+};
+
+/*******************************************************************//**
+Record the number of non_null key values in a given index for
+each n-column prefix of the index where 1 <= n <= dict_index_get_n_unique(index).
+The estimates are eventually stored in the array:
+index->stat_n_non_null_key_vals[], which is indexed from 0 to n-1. */
+static
+void
+btr_record_not_null_field_in_rec(
+/*=============================*/
+	ulint		n_unique,	/*!< in: dict_index_get_n_unique(index),
+					number of columns uniquely determine
+					an index entry */
+	const rec_offs*	offsets,	/*!< in: rec_get_offsets(rec, index),
+					its size could be for all fields or
+					that of "n_unique" */
+	ib_uint64_t*	n_not_null)	/*!< in/out: array to record number of
+					not null rows for n-column prefix */
+{
+	ulint	i;
+
+	ut_ad(rec_offs_n_fields(offsets) >= n_unique);
+
+	if (n_not_null == NULL) {
+		return;
+	}
+
+	for (i = 0; i < n_unique; i++) {
+		if (rec_offs_nth_sql_null(offsets, i)) {
+			break;
+		}
+
+		n_not_null[i]++;
+	}
+}
+
+inline dberr_t
+btr_cur_t::open_random_leaf(rec_offs *&offsets, mem_heap_t *&heap, mtr_t &mtr)
+{
+  ut_ad(!index()->is_spatial());
+  ut_ad(!mtr.get_savepoint());
+
+  mtr_s_lock_index(index(), &mtr);
+
+  if (index()->page == FIL_NULL)
+    return DB_CORRUPTION;
+
+  dberr_t err;
+  auto offset= index()->page;
+  bool merge= false;
+  ulint height= ULINT_UNDEFINED;
+
+  while (buf_block_t *block=
+         btr_block_get(*index(), offset, RW_S_LATCH, merge, &mtr, &err))
+  {
+    page_cur.block= block;
+
+    if (height == ULINT_UNDEFINED)
+    {
+      height= btr_page_get_level(block->page.frame);
+      if (height > BTR_MAX_LEVELS)
+        return DB_CORRUPTION;
+
+      if (height == 0)
+        goto got_leaf;
+    }
+
+    if (height == 0)
+    {
+      mtr.rollback_to_savepoint(0, mtr.get_savepoint() - 1);
+    got_leaf:
+      page_cur.rec= page_get_infimum_rec(block->page.frame);
+      return DB_SUCCESS;
+    }
+
+    if (!--height)
+      merge= !index()->is_clust();
+
+    page_cur_open_on_rnd_user_rec(&page_cur);
+
+    offsets= rec_get_offsets(page_cur.rec, page_cur.index, offsets, 0,
+                             ULINT_UNDEFINED, &heap);
+
+    /* Go to the child node */
+    offset= btr_node_ptr_get_child_page_no(page_cur.rec, offsets);
+  }
+
+  return err;
+}
+
+/** Estimated table level stats from sampled value.
+@param value sampled stats
+@param index index being sampled
+@param sample number of sampled rows
+@param ext_size external stored data size
+@param not_empty table not empty
+@return estimated table wide stats from sampled value */
+#define BTR_TABLE_STATS_FROM_SAMPLE(value, index, sample, ext_size, not_empty) \
+	(((value) * static_cast<ib_uint64_t>(index->stat_n_leaf_pages) \
+	  + (sample) - 1 + (ext_size) + (not_empty)) / ((sample) + (ext_size)))
+
+/** Estimates the number of different key values in a given index, for
+each n-column prefix of the index where 1 <= n <= dict_index_get_n_unique(index).
+The estimates are stored in the array index->stat_n_diff_key_vals[] (indexed
+0..n_uniq-1) and the number of pages that were sampled is saved in
+result.n_sample_sizes[].
+If innodb_stats_method is nulls_ignored, we also record the number of
+non-null values for each prefix and stored the estimates in
+array result.n_non_null_key_vals.
+@param index          B-tree index
+@param bulk_trx_id    the value of index->table->bulk_trx_id at the start
+@return vector with statistics information
+empty vector if the index is unavailable. */
+static
+std::vector<index_field_stats_t>
+btr_estimate_number_of_different_key_vals(dict_index_t* index,
+					  trx_id_t bulk_trx_id)
+{
+	page_t*		page;
+	rec_t*		rec;
+	ulint		n_cols;
+	ib_uint64_t*	n_diff;
+	ib_uint64_t*	n_not_null;
+	ibool		stats_null_not_equal;
+	uintmax_t	n_sample_pages=1; /* number of pages to sample */
+	ulint		not_empty_flag	= 0;
+	ulint		total_external_size = 0;
+	uintmax_t	add_on;
+	mtr_t		mtr;
+	mem_heap_t*	heap		= NULL;
+	rec_offs*	offsets_rec	= NULL;
+	rec_offs*	offsets_next_rec = NULL;
+
+	std::vector<index_field_stats_t> result;
+
+	ut_ad(index->is_btree());
+
+	n_cols = dict_index_get_n_unique(index);
+
+	heap = mem_heap_create((sizeof *n_diff + sizeof *n_not_null)
+			       * n_cols
+			       + dict_index_get_n_fields(index)
+			       * (sizeof *offsets_rec
+				  + sizeof *offsets_next_rec));
+
+	n_diff = (ib_uint64_t*) mem_heap_zalloc(
+		heap, n_cols * sizeof(n_diff[0]));
+
+	n_not_null = NULL;
+
+	/* Check srv_innodb_stats_method setting, and decide whether we
+	need to record non-null value and also decide if NULL is
+	considered equal (by setting stats_null_not_equal value) */
+	switch (srv_innodb_stats_method) {
+	case SRV_STATS_NULLS_IGNORED:
+		n_not_null = (ib_uint64_t*) mem_heap_zalloc(
+			heap, n_cols * sizeof *n_not_null);
+		/* fall through */
+
+	case SRV_STATS_NULLS_UNEQUAL:
+		/* for both SRV_STATS_NULLS_IGNORED and SRV_STATS_NULLS_UNEQUAL
+		case, we will treat NULLs as unequal value */
+		stats_null_not_equal = TRUE;
+		break;
+
+	case SRV_STATS_NULLS_EQUAL:
+		stats_null_not_equal = FALSE;
+		break;
+
+	default:
+		ut_error;
+	}
+
+	if (srv_stats_sample_traditional) {
+		/* It makes no sense to test more pages than are contained
+		in the index, thus we lower the number if it is too high */
+		if (srv_stats_transient_sample_pages > index->stat_index_size) {
+			if (index->stat_index_size > 0) {
+				n_sample_pages = index->stat_index_size;
+			}
+		} else {
+			n_sample_pages = srv_stats_transient_sample_pages;
+		}
+	} else {
+		/* New logaritmic number of pages that are estimated.
+		Number of pages estimated should be between 1 and
+		index->stat_index_size.
+
+		If we have only 0 or 1 index pages then we can only take 1
+		sample. We have already initialized n_sample_pages to 1.
+
+		So taking index size as I and sample as S and log(I)*S as L
+
+		requirement 1) we want the out limit of the expression to not exceed I;
+		requirement 2) we want the ideal pages to be at least S;
+		so the current expression is min(I, max( min(S,I), L)
+
+		looking for simplifications:
+
+		case 1: assume S < I
+		min(I, max( min(S,I), L) -> min(I , max( S, L))
+
+		but since L=LOG2(I)*S and log2(I) >=1   L>S always so max(S,L) = L.
+
+		so we have: min(I , L)
+
+		case 2: assume I < S
+		    min(I, max( min(S,I), L) -> min(I, max( I, L))
+
+		case 2a: L > I
+		    min(I, max( I, L)) -> min(I, L) -> I
+
+		case 2b: when L < I
+		    min(I, max( I, L))  ->  min(I, I ) -> I
+
+		so taking all case2 paths is I, our expression is:
+		n_pages = S < I? min(I,L) : I
+                */
+		if (index->stat_index_size > 1) {
+			n_sample_pages = (srv_stats_transient_sample_pages < index->stat_index_size)
+				? ut_min(index->stat_index_size,
+					 static_cast<ulint>(
+						 log2(double(index->stat_index_size))
+						 * double(srv_stats_transient_sample_pages)))
+				: index->stat_index_size;
+		}
+	}
+
+	/* Sanity check */
+	ut_ad(n_sample_pages > 0 && n_sample_pages <= (index->stat_index_size <= 1 ? 1 : index->stat_index_size));
+
+	/* We sample some pages in the index to get an estimate */
+	btr_cur_t cursor;
+	cursor.page_cur.index = index;
+
+	for (ulint i = 0; i < n_sample_pages; i++) {
+		mtr.start();
+
+		if (cursor.open_random_leaf(offsets_rec, heap, mtr) !=
+                    DB_SUCCESS
+		    || index->table->bulk_trx_id != bulk_trx_id) {
+			mtr.commit();
+			goto exit_loop;
+		}
+
+		/* Count the number of different key values for each prefix of
+		the key on this index page. If the prefix does not determine
+		the index record uniquely in the B-tree, then we subtract one
+		because otherwise our algorithm would give a wrong estimate
+		for an index where there is just one key value. */
+
+		page = btr_cur_get_page(&cursor);
+
+		rec = page_rec_get_next(cursor.page_cur.rec);
+		const ulint n_core = index->n_core_fields;
+
+		if (rec && !page_rec_is_supremum(rec)) {
+			not_empty_flag = 1;
+			offsets_rec = rec_get_offsets(rec, index, offsets_rec,
+						      n_core,
+						      ULINT_UNDEFINED, &heap);
+
+			if (n_not_null != NULL) {
+				btr_record_not_null_field_in_rec(
+					n_cols, offsets_rec, n_not_null);
+			}
+		}
+
+		while (!page_rec_is_supremum(rec)) {
+			ulint	matched_fields;
+			rec_t*	next_rec = page_rec_get_next(rec);
+			if (!next_rec || page_rec_is_supremum(next_rec)) {
+				total_external_size +=
+					btr_rec_get_externally_stored_len(
+						rec, offsets_rec);
+				break;
+			}
+
+			offsets_next_rec = rec_get_offsets(next_rec, index,
+							   offsets_next_rec,
+							   n_core,
+							   ULINT_UNDEFINED,
+							   &heap);
+
+			cmp_rec_rec(rec, next_rec,
+				    offsets_rec, offsets_next_rec,
+				    index, stats_null_not_equal,
+				    &matched_fields);
+
+			for (ulint j = matched_fields; j < n_cols; j++) {
+				/* We add one if this index record has
+				a different prefix from the previous */
+
+				n_diff[j]++;
+			}
+
+			if (n_not_null != NULL) {
+				btr_record_not_null_field_in_rec(
+					n_cols, offsets_next_rec, n_not_null);
+			}
+
+			total_external_size
+				+= btr_rec_get_externally_stored_len(
+					rec, offsets_rec);
+
+			rec = next_rec;
+			/* Initialize offsets_rec for the next round
+			and assign the old offsets_rec buffer to
+			offsets_next_rec. */
+			{
+				rec_offs* offsets_tmp = offsets_rec;
+				offsets_rec = offsets_next_rec;
+				offsets_next_rec = offsets_tmp;
+			}
+		}
+
+		if (n_cols == dict_index_get_n_unique_in_tree(index)
+		    && page_has_siblings(page)) {
+
+			/* If there is more than one leaf page in the tree,
+			we add one because we know that the first record
+			on the page certainly had a different prefix than the
+			last record on the previous index page in the
+			alphabetical order. Before this fix, if there was
+			just one big record on each clustered index page, the
+			algorithm grossly underestimated the number of rows
+			in the table. */
+
+			n_diff[n_cols - 1]++;
+		}
+
+		mtr.commit();
+	}
+
+exit_loop:
+	/* If we saw k borders between different key values on
+	n_sample_pages leaf pages, we can estimate how many
+	there will be in index->stat_n_leaf_pages */
+
+	/* We must take into account that our sample actually represents
+	also the pages used for external storage of fields (those pages are
+	included in index->stat_n_leaf_pages) */
+
+	result.reserve(n_cols);
+
+	for (ulint j = 0; j < n_cols; j++) {
+		index_field_stats_t stat;
+
+		stat.n_diff_key_vals
+			= BTR_TABLE_STATS_FROM_SAMPLE(
+				n_diff[j], index, n_sample_pages,
+				total_external_size, not_empty_flag);
+
+		/* If the tree is small, smaller than
+		10 * n_sample_pages + total_external_size, then
+		the above estimate is ok. For bigger trees it is common that we
+		do not see any borders between key values in the few pages
+		we pick. But still there may be n_sample_pages
+		different key values, or even more. Let us try to approximate
+		that: */
+
+		add_on = index->stat_n_leaf_pages
+			/ (10 * (n_sample_pages
+				 + total_external_size));
+
+		if (add_on > n_sample_pages) {
+			add_on = n_sample_pages;
+		}
+
+		stat.n_diff_key_vals += add_on;
+
+		stat.n_sample_sizes = n_sample_pages;
+
+		if (n_not_null != NULL) {
+			stat.n_non_null_key_vals =
+				 BTR_TABLE_STATS_FROM_SAMPLE(
+					n_not_null[j], index, n_sample_pages,
+					total_external_size, not_empty_flag);
+		}
+
+		result.push_back(stat);
+	}
+
+	mem_heap_free(heap);
+	return result;
+}
+
+/*********************************************************************//**
+Calculates new estimates for index statistics. This function is
+relatively quick and is used to calculate transient statistics that
+are not saved on disk. This was the only way to calculate statistics
+before the Persistent Statistics feature was introduced.
+This function doesn't update the defragmentation related stats.
+Only persistent statistics supports defragmentation stats.
+@return error code
+@retval DB_SUCCESS_LOCKED_REC if the table under bulk insert operation */
+static
+dberr_t
+dict_stats_update_transient_for_index(
+/*==================================*/
+	dict_index_t*	index)	/*!< in/out: index */
+{
+	dberr_t err = DB_SUCCESS;
+	if (srv_force_recovery >= SRV_FORCE_NO_TRX_UNDO
+	    && (srv_force_recovery >= SRV_FORCE_NO_LOG_REDO
+		|| !dict_index_is_clust(index))) {
+		/* If we have set a high innodb_force_recovery
+		level, do not calculate statistics, as a badly
+		corrupted index can cause a crash in it.
+		Initialize some bogus index cardinality
+		statistics, so that the data can be queried in
+		various means, also via secondary indexes. */
+dummy_empty:
+		index->table->stats_mutex_lock();
+		dict_stats_empty_index(index, false);
+		index->table->stats_mutex_unlock();
+		return err;
+#if defined UNIV_DEBUG || defined UNIV_IBUF_DEBUG
+	} else if (ibuf_debug && !dict_index_is_clust(index)) {
+		goto dummy_empty;
+#endif /* UNIV_DEBUG || UNIV_IBUF_DEBUG */
+	} else if (dict_index_is_online_ddl(index) || !index->is_committed()
+		   || !index->table->space) {
+		goto dummy_empty;
+	} else {
+		mtr_t	mtr;
+
+		mtr.start();
+		mtr_sx_lock_index(index, &mtr);
+
+		dberr_t err;
+		buf_block_t* root = btr_root_block_get(index, RW_SX_LATCH,
+						       &mtr, &err);
+		if (!root) {
+invalid:
+			mtr.commit();
+			goto dummy_empty;
+		}
+
+		const auto bulk_trx_id = index->table->bulk_trx_id;
+		if (bulk_trx_id && trx_sys.find(nullptr, bulk_trx_id, false)) {
+			err= DB_SUCCESS_LOCKED_REC;
+			goto invalid;
+		}
+
+		mtr.x_lock_space(index->table->space);
+
+		ulint dummy, size;
+		index->stat_index_size
+			= fseg_n_reserved_pages(*root, PAGE_HEADER
+						+ PAGE_BTR_SEG_LEAF
+						+ root->page.frame, &size,
+						&mtr)
+			+ fseg_n_reserved_pages(*root, PAGE_HEADER
+						+ PAGE_BTR_SEG_TOP
+						+ root->page.frame, &dummy,
+						&mtr);
+
+		mtr.commit();
+
+		index->stat_n_leaf_pages = size ? size : 1;
+
+		/* Do not continue if table decryption has failed or
+		table is already marked as corrupted. */
+		if (index->is_readable()) {
+			std::vector<index_field_stats_t> stats
+				= btr_estimate_number_of_different_key_vals(
+					index, bulk_trx_id);
+
+			if (!stats.empty()) {
+				index->table->stats_mutex_lock();
+				for (size_t i = 0; i < stats.size(); ++i) {
+					index->stat_n_diff_key_vals[i]
+						= stats[i].n_diff_key_vals;
+					index->stat_n_sample_sizes[i]
+						= stats[i].n_sample_sizes;
+					index->stat_n_non_null_key_vals[i]
+						= stats[i].n_non_null_key_vals;
+				}
+				index->table->stats_mutex_unlock();
+			}
+		}
+	}
+
+	return err;
+}
+
+/*********************************************************************//**
+Calculates new estimates for table and index statistics. This function
+is relatively quick and is used to calculate transient statistics that
+are not saved on disk.
+This was the only way to calculate statistics before the
+Persistent Statistics feature was introduced.
+@return error code
+@retval DB_SUCCESS_LOCKED REC if the table under bulk insert operation */
+static
+dberr_t
+dict_stats_update_transient(
+/*========================*/
+	dict_table_t*	table)	/*!< in/out: table */
+{
+	ut_ad(!table->stats_mutex_is_owner());
+
+	dict_index_t*	index;
+	ulint		sum_of_index_sizes	= 0;
+	dberr_t		err = DB_SUCCESS;
+
+	/* Find out the sizes of the indexes and how many different values
+	for the key they approximately have */
+
+	index = dict_table_get_first_index(table);
+
+	if (!table->space) {
+		/* Nothing to do. */
+empty_table:
+		dict_stats_empty_table(table, true);
+		return err;
+	} else if (index == NULL) {
+		/* Table definition is corrupt */
+
+		ib::warn() << "Table " << table->name
+			<< " has no indexes. Cannot calculate statistics.";
+		goto empty_table;
+	}
+
+	for (; index != NULL; index = dict_table_get_next_index(index)) {
+
+		ut_ad(!dict_index_is_ibuf(index));
+
+		if (!index->is_btree()) {
+			continue;
+		}
+
+		if (dict_stats_should_ignore_index(index)
+		    || !index->is_readable()
+		    || err == DB_SUCCESS_LOCKED_REC) {
+			index->table->stats_mutex_lock();
+			dict_stats_empty_index(index, false);
+			index->table->stats_mutex_unlock();
+			continue;
+		}
+
+		err = dict_stats_update_transient_for_index(index);
+
+		sum_of_index_sizes += index->stat_index_size;
+	}
+
+	table->stats_mutex_lock();
+
+	index = dict_table_get_first_index(table);
+
+	table->stat_n_rows = index->stat_n_diff_key_vals[
+		dict_index_get_n_unique(index) - 1];
+
+	table->stat_clustered_index_size = index->stat_index_size;
+
+	table->stat_sum_of_other_index_sizes = sum_of_index_sizes
+		- index->stat_index_size;
+
+	table->stats_last_recalc = time(NULL);
+
+	table->stat_modified_counter = 0;
+
+	table->stat_initialized = TRUE;
+
+	table->stats_mutex_unlock();
+
+	return err;
+}
+
+/** Open a cursor at the first page in a tree level.
+@param page_cur  cursor
+@param level     level to search for (0=leaf)
+@param mtr       mini-transaction */
+static dberr_t page_cur_open_level(page_cur_t *page_cur, ulint level,
+                                   mtr_t *mtr)
+{
+  mem_heap_t *heap= nullptr;
+  rec_offs offsets_[REC_OFFS_NORMAL_SIZE];
+  rec_offs *offsets= offsets_;
+  dberr_t err;
+
+  dict_index_t *const index= page_cur->index;
+
+  rec_offs_init(offsets_);
+  ut_ad(level != ULINT_UNDEFINED);
+  ut_ad(mtr->memo_contains_flagged(&index->lock, MTR_MEMO_SX_LOCK));
+  ut_ad(mtr->get_savepoint() == 1);
+
+  uint32_t page= index->page;
+
+  for (ulint height = ULINT_UNDEFINED;; height--)
+  {
+    buf_block_t* block=
+      btr_block_get(*index, page, RW_S_LATCH,
+                    !height && !index->is_clust(), mtr, &err);
+    if (!block)
+      break;
+
+    const uint32_t l= btr_page_get_level(block->page.frame);
+
+    if (height == ULINT_UNDEFINED)
+    {
+      ut_ad(!heap);
+      /* We are in the root node */
+      height= l;
+      if (UNIV_UNLIKELY(height < level))
+        return DB_CORRUPTION;
+    }
+    else if (UNIV_UNLIKELY(height != l) || page_has_prev(block->page.frame))
+    {
+      err= DB_CORRUPTION;
+      break;
+    }
+
+    page_cur_set_before_first(block, page_cur);
+
+    if (height == level)
+      break;
+
+    ut_ad(height);
+
+    if (!page_cur_move_to_next(page_cur))
+    {
+      err= DB_CORRUPTION;
+      break;
+    }
+
+    offsets= rec_get_offsets(page_cur->rec, index, offsets, 0, ULINT_UNDEFINED,
+                             &heap);
+    page= btr_node_ptr_get_child_page_no(page_cur->rec, offsets);
+  }
+
+  if (UNIV_LIKELY_NULL(heap))
+    mem_heap_free(heap);
+
+  /* Release all page latches except the one on the desired page. */
+  const auto end= mtr->get_savepoint();
+  if (end > 1)
+    mtr->rollback_to_savepoint(1, end - 1);
+
+  return err;
+}
+
+/** Open a cursor at the first page in a tree level.
+@param page_cur  cursor
+@param level     level to search for (0=leaf)
+@param mtr       mini-transaction
+@param index     index tree */
+static dberr_t btr_pcur_open_level(btr_pcur_t *pcur, ulint level, mtr_t *mtr,
+                                   dict_index_t *index)
+{
+  pcur->latch_mode= BTR_SEARCH_LEAF;
+  pcur->search_mode= PAGE_CUR_G;
+  pcur->pos_state= BTR_PCUR_IS_POSITIONED;
+  pcur->btr_cur.page_cur.index= index;
+  return page_cur_open_level(&pcur->btr_cur.page_cur, level, mtr);
+}
+
+
+/* @{ Pseudo code about the relation between the following functions
+
+let N = N_SAMPLE_PAGES(index)
+
+dict_stats_analyze_index()
+  for each n_prefix
+    search for good enough level:
+      dict_stats_analyze_index_level() // only called if level has <= N pages
+        // full scan of the level in one mtr
+        collect statistics about the given level
+      if we are not satisfied with the level, search next lower level
+    we have found a good enough level here
+    dict_stats_analyze_index_for_n_prefix(that level, stats collected above)
+      // full scan of the level in one mtr
+      dive below some records and analyze the leaf page there:
+      dict_stats_analyze_index_below_cur()
+@} */
+
+/*********************************************************************//**
+Find the total number and the number of distinct keys on a given level in
+an index. Each of the 1..n_uniq prefixes are looked up and the results are
+saved in the array n_diff[0] .. n_diff[n_uniq - 1]. The total number of
+records on the level is saved in total_recs.
+Also, the index of the last record in each group of equal records is saved
+in n_diff_boundaries[0..n_uniq - 1], records indexing starts from the leftmost
+record on the level and continues cross pages boundaries, counting from 0. */
+static
+void
+dict_stats_analyze_index_level(
+/*===========================*/
+	dict_index_t*	index,		/*!< in: index */
+	ulint		level,		/*!< in: level */
+	ib_uint64_t*	n_diff,		/*!< out: array for number of
+					distinct keys for all prefixes */
+	ib_uint64_t*	total_recs,	/*!< out: total number of records */
+	ib_uint64_t*	total_pages,	/*!< out: total number of pages */
+	boundaries_t*	n_diff_boundaries,/*!< out: boundaries of the groups
+					of distinct keys */
+	mtr_t*		mtr)		/*!< in/out: mini-transaction */
+{
+	ulint		n_uniq;
+	mem_heap_t*	heap;
+	btr_pcur_t	pcur;
+	const page_t*	page;
+	const rec_t*	rec;
+	const rec_t*	prev_rec;
+	bool		prev_rec_is_copied;
+	byte*		prev_rec_buf = NULL;
+	ulint		prev_rec_buf_size = 0;
+	rec_offs*	rec_offsets;
+	rec_offs*	prev_rec_offsets;
+	ulint		i;
+
+	DEBUG_PRINTF("    %s(table=%s, index=%s, level=" ULINTPF ")\n",
+		     __func__, index->table->name, index->name, level);
+
+	*total_recs = 0;
+	*total_pages = 0;
+
+	n_uniq = dict_index_get_n_unique(index);
+
+	/* elements in the n_diff array are 0..n_uniq-1 (inclusive) */
+	memset(n_diff, 0x0, n_uniq * sizeof(n_diff[0]));
+
+	/* Allocate space for the offsets header (the allocation size at
+	offsets[0] and the REC_OFFS_HEADER_SIZE bytes), and n_uniq + 1,
+	so that this will never be less than the size calculated in
+	rec_get_offsets_func(). */
+	i = (REC_OFFS_HEADER_SIZE + 1 + 1) + n_uniq;
+
+	heap = mem_heap_create((2 * sizeof *rec_offsets) * i);
+	rec_offsets = static_cast<rec_offs*>(
+		mem_heap_alloc(heap, i * sizeof *rec_offsets));
+	prev_rec_offsets = static_cast<rec_offs*>(
+		mem_heap_alloc(heap, i * sizeof *prev_rec_offsets));
+	rec_offs_set_n_alloc(rec_offsets, i);
+	rec_offs_set_n_alloc(prev_rec_offsets, i);
+
+	/* reset the dynamic arrays n_diff_boundaries[0..n_uniq-1] */
+	if (n_diff_boundaries != NULL) {
+		for (i = 0; i < n_uniq; i++) {
+			n_diff_boundaries[i].erase(
+				n_diff_boundaries[i].begin(),
+				n_diff_boundaries[i].end());
+		}
+	}
+
+	/* Position pcur on the leftmost record on the leftmost page
+	on the desired level. */
+
+	if (btr_pcur_open_level(&pcur, level, mtr, index) != DB_SUCCESS
+	    || !btr_pcur_move_to_next_on_page(&pcur)) {
+		goto func_exit;
+	}
+
+	page = btr_pcur_get_page(&pcur);
+
+	/* The page must not be empty, except when
+	it is the root page (and the whole index is empty). */
+	ut_ad(btr_pcur_is_on_user_rec(&pcur) || page_is_leaf(page));
+
+	prev_rec = NULL;
+	prev_rec_is_copied = false;
+
+	if (REC_INFO_MIN_REC_FLAG & rec_get_info_bits(
+		    btr_pcur_get_rec(&pcur), page_is_comp(page))) {
+		ut_ad(btr_pcur_is_on_user_rec(&pcur));
+		if (level == 0) {
+			/* Skip the metadata pseudo-record */
+			ut_ad(index->is_instant());
+			btr_pcur_move_to_next_user_rec(&pcur, mtr);
+		}
+	} else if (UNIV_UNLIKELY(level != 0)) {
+		/* The first record on the leftmost page must be
+		marked as such on each level except the leaf level. */
+		goto func_exit;
+	}
+
+	/* iterate over all user records on this level
+	and compare each two adjacent ones, even the last on page
+	X and the fist on page X+1 */
+	for (;
+	     btr_pcur_is_on_user_rec(&pcur);
+	     btr_pcur_move_to_next_user_rec(&pcur, mtr)) {
+
+		bool	rec_is_last_on_page;
+
+		rec = btr_pcur_get_rec(&pcur);
+
+		/* If rec and prev_rec are on different pages, then prev_rec
+		must have been copied, because we hold latch only on the page
+		where rec resides. */
+		if (prev_rec != NULL
+		    && page_align(rec) != page_align(prev_rec)) {
+
+			ut_a(prev_rec_is_copied);
+		}
+
+		rec_is_last_on_page =
+			page_rec_is_supremum(page_rec_get_next_const(rec));
+
+		/* increment the pages counter at the end of each page */
+		if (rec_is_last_on_page) {
+
+			(*total_pages)++;
+		}
+
+		/* Skip delete-marked records on the leaf level. If we
+		do not skip them, then ANALYZE quickly after DELETE
+		could count them or not (purge may have already wiped
+		them away) which brings non-determinism. We skip only
+		leaf-level delete marks because delete marks on
+		non-leaf level do not make sense. */
+
+		if (level == 0
+		    && !srv_stats_include_delete_marked
+		    && rec_get_deleted_flag(rec, page_rec_is_comp(rec))) {
+			if (rec_is_last_on_page
+			    && !prev_rec_is_copied
+			    && prev_rec != NULL) {
+				/* copy prev_rec */
+
+				prev_rec_offsets = rec_get_offsets(
+					prev_rec, index, prev_rec_offsets,
+					index->n_core_fields,
+					n_uniq, &heap);
+
+				prev_rec = rec_copy_prefix_to_buf(
+					prev_rec, index, n_uniq,
+					&prev_rec_buf, &prev_rec_buf_size);
+
+				prev_rec_is_copied = true;
+			}
+
+			continue;
+		}
+		rec_offsets = rec_get_offsets(rec, index, rec_offsets,
+					      level ? 0 : index->n_core_fields,
+					      n_uniq, &heap);
+
+		(*total_recs)++;
+
+		if (prev_rec != NULL) {
+			ulint	matched_fields;
+
+			prev_rec_offsets = rec_get_offsets(
+				prev_rec, index, prev_rec_offsets,
+				level ? 0 : index->n_core_fields,
+				n_uniq, &heap);
+
+			cmp_rec_rec(prev_rec, rec,
+				    prev_rec_offsets, rec_offsets, index,
+				    false, &matched_fields);
+
+			for (i = matched_fields; i < n_uniq; i++) {
+
+				if (n_diff_boundaries != NULL) {
+					/* push the index of the previous
+					record, that is - the last one from
+					a group of equal keys */
+
+					ib_uint64_t	idx;
+
+					/* the index of the current record
+					is total_recs - 1, the index of the
+					previous record is total_recs - 2;
+					we know that idx is not going to
+					become negative here because if we
+					are in this branch then there is a
+					previous record and thus
+					total_recs >= 2 */
+					idx = *total_recs - 2;
+
+					n_diff_boundaries[i].push_back(idx);
+				}
+
+				/* increment the number of different keys
+				for n_prefix=i+1 (e.g. if i=0 then we increment
+				for n_prefix=1 which is stored in n_diff[0]) */
+				n_diff[i]++;
+			}
+		} else {
+			/* this is the first non-delete marked record */
+			for (i = 0; i < n_uniq; i++) {
+				n_diff[i] = 1;
+			}
+		}
+
+		if (rec_is_last_on_page) {
+			/* end of a page has been reached */
+
+			/* we need to copy the record instead of assigning
+			like prev_rec = rec; because when we traverse the
+			records on this level at some point we will jump from
+			one page to the next and then rec and prev_rec will
+			be on different pages and
+			btr_cur_move_to_next_user_rec() will release the
+			latch on the page that prev_rec is on */
+			prev_rec = rec_copy_prefix_to_buf(
+				rec, index, n_uniq,
+				&prev_rec_buf, &prev_rec_buf_size);
+			prev_rec_is_copied = true;
+
+		} else {
+			/* still on the same page, the next call to
+			btr_cur_move_to_next_user_rec() will not jump
+			on the next page, we can simply assign pointers
+			instead of copying the records like above */
+
+			prev_rec = rec;
+			prev_rec_is_copied = false;
+		}
+	}
+
+	/* if *total_pages is left untouched then the above loop was not
+	entered at all and there is one page in the whole tree which is
+	empty or the loop was entered but this is level 0, contains one page
+	and all records are delete-marked */
+	if (*total_pages == 0) {
+
+		ut_ad(level == 0);
+		ut_ad(*total_recs == 0);
+
+		*total_pages = 1;
+	}
+
+	/* if there are records on this level and boundaries
+	should be saved */
+	if (*total_recs > 0 && n_diff_boundaries != NULL) {
+
+		/* remember the index of the last record on the level as the
+		last one from the last group of equal keys; this holds for
+		all possible prefixes */
+		for (i = 0; i < n_uniq; i++) {
+			ib_uint64_t	idx;
+
+			idx = *total_recs - 1;
+
+			n_diff_boundaries[i].push_back(idx);
+		}
+	}
+
+	/* now in n_diff_boundaries[i] there are exactly n_diff[i] integers,
+	for i=0..n_uniq-1 */
+
+#ifdef UNIV_STATS_DEBUG
+	for (i = 0; i < n_uniq; i++) {
+
+		DEBUG_PRINTF("    %s(): total recs: " UINT64PF
+			     ", total pages: " UINT64PF
+			     ", n_diff[" ULINTPF "]: " UINT64PF "\n",
+			     __func__, *total_recs,
+			     *total_pages,
+			     i, n_diff[i]);
+
+#if 0
+		if (n_diff_boundaries != NULL) {
+			ib_uint64_t	j;
+
+			DEBUG_PRINTF("    %s(): boundaries[%lu]: ",
+				     __func__, i);
+
+			for (j = 0; j < n_diff[i]; j++) {
+				ib_uint64_t	idx;
+
+				idx = n_diff_boundaries[i][j];
+
+				DEBUG_PRINTF(UINT64PF "=" UINT64PF ", ",
+					     j, idx);
+			}
+			DEBUG_PRINTF("\n");
+		}
+#endif
+	}
+#endif /* UNIV_STATS_DEBUG */
+
+func_exit:
+	ut_free(prev_rec_buf);
+	mem_heap_free(heap);
+}
+
+
+/************************************************************//**
+Gets the pointer to the next non delete-marked record on the page.
+If all subsequent records are delete-marked, then this function
+will return the supremum record.
+@return pointer to next non delete-marked record or pointer to supremum */
+static
+const rec_t*
+page_rec_get_next_non_del_marked(
+/*=============================*/
+	const rec_t*	rec)	/*!< in: pointer to record */
+{
+  const page_t *const page= page_align(rec);
+
+  if (page_is_comp(page))
+  {
+    for (rec= page_rec_get_next_low(rec, TRUE);
+         rec && rec_get_deleted_flag(rec, TRUE);
+         rec= page_rec_get_next_low(rec, TRUE));
+    return rec ? rec : page + PAGE_NEW_SUPREMUM;
+  }
+  else
+  {
+    for (rec= page_rec_get_next_low(rec, FALSE);
+         rec && rec_get_deleted_flag(rec, FALSE);
+         rec= page_rec_get_next_low(rec, FALSE));
+    return rec ? rec : page + PAGE_OLD_SUPREMUM;
+  }
+}
+
+/** Scan a page, reading records from left to right and counting the number
+of distinct records (looking only at the first n_prefix
+columns) and the number of external pages pointed by records from this page.
+If scan_method is QUIT_ON_FIRST_NON_BORING then the function
+will return as soon as it finds a record that does not match its neighbor
+to the right, which means that in the case of QUIT_ON_FIRST_NON_BORING the
+returned n_diff can either be 0 (empty page), 1 (the whole page has all keys
+equal) or 2 (the function found a non-boring record and returned).
+@param[out]	out_rec			record, or NULL
+@param[out]	offsets1		rec_get_offsets() working space (must
+be big enough)
+@param[out]	offsets2		rec_get_offsets() working space (must
+be big enough)
+@param[in]	index			index of the page
+@param[in]	page			the page to scan
+@param[in]	n_prefix		look at the first n_prefix columns
+@param[in]	n_core			0, or index->n_core_fields for leaf
+@param[out]	n_diff			number of distinct records encountered
+@param[out]	n_external_pages	if this is non-NULL then it will be set
+to the number of externally stored pages which were encountered
+@return offsets1 or offsets2 (the offsets of *out_rec),
+or NULL if the page is empty and does not contain user records. */
+UNIV_INLINE
+rec_offs*
+dict_stats_scan_page(
+	const rec_t**		out_rec,
+	rec_offs*		offsets1,
+	rec_offs*		offsets2,
+	const dict_index_t*	index,
+	const page_t*		page,
+	ulint			n_prefix,
+	ulint		 	n_core,
+	ib_uint64_t*		n_diff,
+	ib_uint64_t*		n_external_pages)
+{
+	rec_offs*	offsets_rec		= offsets1;
+	rec_offs*	offsets_next_rec	= offsets2;
+	const rec_t*	rec;
+	const rec_t*	next_rec;
+	/* A dummy heap, to be passed to rec_get_offsets().
+	Because offsets1,offsets2 should be big enough,
+	this memory heap should never be used. */
+	mem_heap_t*	heap			= NULL;
+	ut_ad(!!n_core == page_is_leaf(page));
+	const rec_t*	(*get_next)(const rec_t*)
+		= !n_core || srv_stats_include_delete_marked
+		? page_rec_get_next_const
+		: page_rec_get_next_non_del_marked;
+
+	const bool	should_count_external_pages = n_external_pages != NULL;
+
+	if (should_count_external_pages) {
+		*n_external_pages = 0;
+	}
+
+	rec = get_next(page_get_infimum_rec(page));
+
+	if (!rec || page_rec_is_supremum(rec)) {
+		/* the page is empty or contains only delete-marked records */
+		*n_diff = 0;
+		*out_rec = NULL;
+		return(NULL);
+	}
+
+	offsets_rec = rec_get_offsets(rec, index, offsets_rec, n_core,
+				      ULINT_UNDEFINED, &heap);
+
+	if (should_count_external_pages) {
+		*n_external_pages += btr_rec_get_externally_stored_len(
+			rec, offsets_rec);
+	}
+
+	next_rec = get_next(rec);
+
+	*n_diff = 1;
+
+	while (next_rec && !page_rec_is_supremum(next_rec)) {
+
+		ulint	matched_fields;
+
+		offsets_next_rec = rec_get_offsets(next_rec, index,
+						   offsets_next_rec, n_core,
+						   ULINT_UNDEFINED,
+						   &heap);
+
+		/* check whether rec != next_rec when looking at
+		the first n_prefix fields */
+		cmp_rec_rec(rec, next_rec, offsets_rec, offsets_next_rec,
+			    index, false, &matched_fields);
+
+		if (matched_fields < n_prefix) {
+			/* rec != next_rec, => rec is non-boring */
+
+			(*n_diff)++;
+
+			if (!n_core) {
+				break;
+			}
+		}
+
+		rec = next_rec;
+		/* Assign offsets_rec = offsets_next_rec so that
+		offsets_rec matches with rec which was just assigned
+		rec = next_rec above.  Also need to point
+		offsets_next_rec to the place where offsets_rec was
+		pointing before because we have just 2 placeholders
+		where data is actually stored: offsets1 and offsets2
+		and we are using them in circular fashion
+		(offsets[_next]_rec are just pointers to those
+		placeholders). */
+		std::swap(offsets_rec, offsets_next_rec);
+
+		if (should_count_external_pages) {
+			*n_external_pages += btr_rec_get_externally_stored_len(
+				rec, offsets_rec);
+		}
+
+		next_rec = get_next(next_rec);
+	}
+
+	/* offsets1,offsets2 should have been big enough */
+	ut_a(heap == NULL);
+	*out_rec = rec;
+	return(offsets_rec);
+}
+
+/** Dive below the current position of a cursor and calculate the number of
+distinct records on the leaf page, when looking at the fist n_prefix
+columns. Also calculate the number of external pages pointed by records
+on the leaf page.
+@param[in]	cur			cursor
+@param[in]	n_prefix		look at the first n_prefix columns
+when comparing records
+@param[out]	n_diff			number of distinct records
+@param[out]	n_external_pages	number of external pages
+@return number of distinct records on the leaf page */
+static
+void
+dict_stats_analyze_index_below_cur(
+	const btr_cur_t*	cur,
+	ulint			n_prefix,
+	ib_uint64_t*		n_diff,
+	ib_uint64_t*		n_external_pages)
+{
+	dict_index_t*	index;
+	buf_block_t*	block;
+	const page_t*	page;
+	mem_heap_t*	heap;
+	const rec_t*	rec;
+	rec_offs*	offsets1;
+	rec_offs*	offsets2;
+	rec_offs*	offsets_rec;
+	ulint		size;
+	mtr_t		mtr;
+
+	index = btr_cur_get_index(cur);
+
+	/* Allocate offsets for the record and the node pointer, for
+	node pointer records. In a secondary index, the node pointer
+	record will consist of all index fields followed by a child
+	page number.
+	Allocate space for the offsets header (the allocation size at
+	offsets[0] and the REC_OFFS_HEADER_SIZE bytes), and n_fields + 1,
+	so that this will never be less than the size calculated in
+	rec_get_offsets_func(). */
+	size = (1 + REC_OFFS_HEADER_SIZE) + 1 + dict_index_get_n_fields(index);
+
+	heap = mem_heap_create(size * (sizeof *offsets1 + sizeof *offsets2));
+
+	offsets1 = static_cast<rec_offs*>(mem_heap_alloc(
+			heap, size * sizeof *offsets1));
+
+	offsets2 = static_cast<rec_offs*>(mem_heap_alloc(
+			heap, size * sizeof *offsets2));
+
+	rec_offs_set_n_alloc(offsets1, size);
+	rec_offs_set_n_alloc(offsets2, size);
+
+	rec = btr_cur_get_rec(cur);
+	page = page_align(rec);
+	ut_ad(!page_rec_is_leaf(rec));
+
+	offsets_rec = rec_get_offsets(rec, index, offsets1, 0,
+				      ULINT_UNDEFINED, &heap);
+
+	page_id_t		page_id(index->table->space_id,
+					btr_node_ptr_get_child_page_no(
+						rec, offsets_rec));
+	const ulint zip_size = index->table->space->zip_size();
+
+	/* assume no external pages by default - in case we quit from this
+	function without analyzing any leaf pages */
+	*n_external_pages = 0;
+
+	mtr_start(&mtr);
+
+	/* descend to the leaf level on the B-tree */
+	for (;;) {
+		dberr_t err;
+
+		block = buf_page_get_gen(page_id, zip_size,
+					 RW_S_LATCH, NULL, BUF_GET,
+					 &mtr, &err,
+					 !index->is_clust()
+					 && 1 == btr_page_get_level(page));
+		if (!block) {
+			goto func_exit;
+		}
+
+		page = block->page.frame;
+
+		if (page_is_leaf(page)) {
+			/* leaf level */
+			break;
+		}
+		/* else */
+
+		/* search for the first non-boring record on the page */
+		offsets_rec = dict_stats_scan_page(
+			&rec, offsets1, offsets2, index, page, n_prefix,
+			0, n_diff, NULL);
+
+		/* pages on level > 0 are not allowed to be empty */
+		ut_a(offsets_rec != NULL);
+		/* if page is not empty (offsets_rec != NULL) then n_diff must
+		be > 0, otherwise there is a bug in dict_stats_scan_page() */
+		ut_a(*n_diff > 0);
+
+		if (*n_diff == 1) {
+			mtr_commit(&mtr);
+
+			/* page has all keys equal and the end of the page
+			was reached by dict_stats_scan_page(), no need to
+			descend to the leaf level */
+			mem_heap_free(heap);
+			/* can't get an estimate for n_external_pages here
+			because we do not dive to the leaf level, assume no
+			external pages (*n_external_pages was assigned to 0
+			above). */
+			return;
+		}
+		/* else */
+
+		/* when we instruct dict_stats_scan_page() to quit on the
+		first non-boring record it finds, then the returned n_diff
+		can either be 0 (empty page), 1 (page has all keys equal) or
+		2 (non-boring record was found) */
+		ut_a(*n_diff == 2);
+
+		/* we have a non-boring record in rec, descend below it */
+
+		page_id.set_page_no(
+			btr_node_ptr_get_child_page_no(rec, offsets_rec));
+	}
+
+	/* make sure we got a leaf page as a result from the above loop */
+	ut_ad(page_is_leaf(page));
+
+	/* scan the leaf page and find the number of distinct keys,
+	when looking only at the first n_prefix columns; also estimate
+	the number of externally stored pages pointed by records on this
+	page */
+
+	offsets_rec = dict_stats_scan_page(
+		&rec, offsets1, offsets2, index, page, n_prefix,
+		index->n_core_fields, n_diff,
+		n_external_pages);
+
+#if 0
+	DEBUG_PRINTF("      %s(): n_diff below page_no=%lu: " UINT64PF "\n",
+		     __func__, page_no, n_diff);
+#endif
+
+func_exit:
+	mtr_commit(&mtr);
+	mem_heap_free(heap);
+}
+
+/** Input data that is used to calculate dict_index_t::stat_n_diff_key_vals[]
+for each n-columns prefix (n from 1 to n_uniq). */
+struct n_diff_data_t {
+	/** Index of the level on which the descent through the btree
+	stopped. level 0 is the leaf level. This is >= 1 because we
+	avoid scanning the leaf level because it may contain too many
+	pages and doing so is useless when combined with the random dives -
+	if we are to scan the leaf level, this means a full scan and we can
+	simply do that instead of fiddling with picking random records higher
+	in the tree and to dive below them. At the start of the analyzing
+	we may decide to do full scan of the leaf level, but then this
+	structure is not used in that code path. */
+	ulint		level;
+
+	/** Number of records on the level where the descend through the btree
+	stopped. When we scan the btree from the root, we stop at some mid
+	level, choose some records from it and dive below them towards a leaf
+	page to analyze. */
+	ib_uint64_t	n_recs_on_level;
+
+	/** Number of different key values that were found on the mid level. */
+	ib_uint64_t	n_diff_on_level;
+
+	/** Number of leaf pages that are analyzed. This is also the same as
+	the number of records that we pick from the mid level and dive below
+	them. */
+	ib_uint64_t	n_leaf_pages_to_analyze;
+
+	/** Cumulative sum of the number of different key values that were
+	found on all analyzed pages. */
+	ib_uint64_t	n_diff_all_analyzed_pages;
+
+	/** Cumulative sum of the number of external pages (stored outside of
+	the btree but in the same file segment). */
+	ib_uint64_t	n_external_pages_sum;
+};
+
+/** Estimate the number of different key values in an index when looking at
+the first n_prefix columns. For a given level in an index select
+n_diff_data->n_leaf_pages_to_analyze records from that level and dive below
+them to the corresponding leaf pages, then scan those leaf pages and save the
+sampling results in n_diff_data->n_diff_all_analyzed_pages.
+@param[in]	index			index
+@param[in]	n_prefix		look at first 'n_prefix' columns when
+comparing records
+@param[in]	boundaries		a vector that contains
+n_diff_data->n_diff_on_level integers each of which represents the index (on
+level 'level', counting from left/smallest to right/biggest from 0) of the
+last record from each group of distinct keys
+@param[in,out]	n_diff_data		n_diff_all_analyzed_pages and
+n_external_pages_sum in this structure will be set by this function. The
+members level, n_diff_on_level and n_leaf_pages_to_analyze must be set by the
+caller in advance - they are used by some calculations inside this function
+@param[in,out]	mtr			mini-transaction */
+static
+void
+dict_stats_analyze_index_for_n_prefix(
+	dict_index_t*		index,
+	ulint			n_prefix,
+	const boundaries_t*	boundaries,
+	n_diff_data_t*		n_diff_data,
+	mtr_t*			mtr)
+{
+	btr_pcur_t	pcur;
+	const page_t*	page;
+	ib_uint64_t	rec_idx;
+	ib_uint64_t	i;
+
+#if 0
+	DEBUG_PRINTF("    %s(table=%s, index=%s, level=%lu, n_prefix=%lu,"
+		     " n_diff_on_level=" UINT64PF ")\n",
+		     __func__, index->table->name, index->name, level,
+		     n_prefix, n_diff_data->n_diff_on_level);
+#endif
+
+	ut_ad(n_diff_data->level);
+
+	/* Position pcur on the leftmost record on the leftmost page
+	on the desired level. */
+
+	n_diff_data->n_diff_all_analyzed_pages = 0;
+	n_diff_data->n_external_pages_sum = 0;
+
+	if (btr_pcur_open_level(&pcur, n_diff_data->level, mtr, index)
+	    != DB_SUCCESS
+	    || !btr_pcur_move_to_next_on_page(&pcur)) {
+		return;
+	}
+
+	page = btr_pcur_get_page(&pcur);
+
+	const rec_t*	first_rec = btr_pcur_get_rec(&pcur);
+
+	/* The page must not be empty, except when
+	it is the root page (and the whole index is empty). */
+	if (page_has_prev(page)
+	    || !btr_pcur_is_on_user_rec(&pcur)
+	    || btr_page_get_level(page) != n_diff_data->level
+	    || first_rec != page_rec_get_next_const(page_get_infimum_rec(page))
+	    || !(rec_get_info_bits(first_rec, page_is_comp(page))
+		 & REC_INFO_MIN_REC_FLAG)) {
+		return;
+	}
+
+	const ib_uint64_t	last_idx_on_level = boundaries->at(
+		static_cast<unsigned>(n_diff_data->n_diff_on_level - 1));
+
+	rec_idx = 0;
+
+	for (i = 0; i < n_diff_data->n_leaf_pages_to_analyze; i++) {
+		/* there are n_diff_on_level elements
+		in 'boundaries' and we divide those elements
+		into n_leaf_pages_to_analyze segments, for example:
+
+		let n_diff_on_level=100, n_leaf_pages_to_analyze=4, then:
+		segment i=0:  [0, 24]
+		segment i=1: [25, 49]
+		segment i=2: [50, 74]
+		segment i=3: [75, 99] or
+
+		let n_diff_on_level=1, n_leaf_pages_to_analyze=1, then:
+		segment i=0: [0, 0] or
+
+		let n_diff_on_level=2, n_leaf_pages_to_analyze=2, then:
+		segment i=0: [0, 0]
+		segment i=1: [1, 1] or
+
+		let n_diff_on_level=13, n_leaf_pages_to_analyze=7, then:
+		segment i=0:  [0,  0]
+		segment i=1:  [1,  2]
+		segment i=2:  [3,  4]
+		segment i=3:  [5,  6]
+		segment i=4:  [7,  8]
+		segment i=5:  [9, 10]
+		segment i=6: [11, 12]
+
+		then we select a random record from each segment and dive
+		below it */
+		const ib_uint64_t	n_diff = n_diff_data->n_diff_on_level;
+		const ib_uint64_t	n_pick
+			= n_diff_data->n_leaf_pages_to_analyze;
+
+		const ib_uint64_t	left = n_diff * i / n_pick;
+		const ib_uint64_t	right = n_diff * (i + 1) / n_pick - 1;
+
+		ut_a(left <= right);
+		ut_a(right <= last_idx_on_level);
+
+		const ulint	rnd = ut_rnd_interval(
+			static_cast<ulint>(right - left));
+
+		const ib_uint64_t	dive_below_idx
+			= boundaries->at(static_cast<unsigned>(left + rnd));
+
+#if 0
+		DEBUG_PRINTF("    %s(): dive below record with index="
+			     UINT64PF "\n", __func__, dive_below_idx);
+#endif
+
+		/* seek to the record with index dive_below_idx */
+		while (rec_idx < dive_below_idx
+		       && btr_pcur_is_on_user_rec(&pcur)) {
+
+			btr_pcur_move_to_next_user_rec(&pcur, mtr);
+			rec_idx++;
+		}
+
+		/* if the level has finished before the record we are
+		searching for, this means that the B-tree has changed in
+		the meantime, quit our sampling and use whatever stats
+		we have collected so far */
+		if (rec_idx < dive_below_idx) {
+
+			ut_ad(!btr_pcur_is_on_user_rec(&pcur));
+			break;
+		}
+
+		/* it could be that the tree has changed in such a way that
+		the record under dive_below_idx is the supremum record, in
+		this case rec_idx == dive_below_idx and pcur is positioned
+		on the supremum, we do not want to dive below it */
+		if (!btr_pcur_is_on_user_rec(&pcur)) {
+			break;
+		}
+
+		ut_a(rec_idx == dive_below_idx);
+
+		ib_uint64_t	n_diff_on_leaf_page;
+		ib_uint64_t	n_external_pages;
+
+		dict_stats_analyze_index_below_cur(btr_pcur_get_btr_cur(&pcur),
+						   n_prefix,
+						   &n_diff_on_leaf_page,
+						   &n_external_pages);
+
+		/* We adjust n_diff_on_leaf_page here to avoid counting
+		one value twice - once as the last on some page and once
+		as the first on another page. Consider the following example:
+		Leaf level:
+		page: (2,2,2,2,3,3)
+		... many pages like (3,3,3,3,3,3) ...
+		page: (3,3,3,3,5,5)
+		... many pages like (5,5,5,5,5,5) ...
+		page: (5,5,5,5,8,8)
+		page: (8,8,8,8,9,9)
+		our algo would (correctly) get an estimate that there are
+		2 distinct records per page (average). Having 4 pages below
+		non-boring records, it would (wrongly) estimate the number
+		of distinct records to 8. */
+		if (n_diff_on_leaf_page > 0) {
+			n_diff_on_leaf_page--;
+		}
+
+		n_diff_data->n_diff_all_analyzed_pages += n_diff_on_leaf_page;
+
+		n_diff_data->n_external_pages_sum += n_external_pages;
+	}
+}
+
+/** statistics for an index */
+struct index_stats_t
+{
+  std::vector<index_field_stats_t> stats;
+  ulint index_size;
+  ulint n_leaf_pages;
+
+  index_stats_t(ulint n_uniq) : index_size(1), n_leaf_pages(1)
+  {
+    stats.reserve(n_uniq);
+    for (ulint i= 0; i < n_uniq; ++i)
+      stats.push_back(index_field_stats_t{0, 1, 0});
+  }
+
+  void set_bulk_operation()
+  {
+    memset((void*) &stats[0], 0xff, stats.size() * sizeof stats[0]);
+  }
+
+  bool is_bulk_operation() const
+  {
+    for (auto &s : stats)
+      if (!s.is_bulk_operation())
+        return false;
+    return true;
+  }
+};
+
+/** Set dict_index_t::stat_n_diff_key_vals[] and stat_n_sample_sizes[].
+@param[in]	n_diff_data	input data to use to derive the results
+@param[in,out]	index_stats	index stats to set */
+UNIV_INLINE
+void
+dict_stats_index_set_n_diff(
+	const n_diff_data_t*	n_diff_data,
+	index_stats_t&		index_stats)
+{
+	for (ulint n_prefix = index_stats.stats.size();
+	     n_prefix >= 1;
+	     n_prefix--) {
+		/* n_diff_all_analyzed_pages can be 0 here if
+		all the leaf pages sampled contained only
+		delete-marked records. In this case we should assign
+		0 to index->stat_n_diff_key_vals[n_prefix - 1], which
+		the formula below does. */
+
+		const n_diff_data_t*	data = &n_diff_data[n_prefix - 1];
+
+		ut_ad(data->n_leaf_pages_to_analyze > 0);
+		ut_ad(data->n_recs_on_level > 0);
+
+		ib_uint64_t	n_ordinary_leaf_pages;
+
+		if (data->level == 1) {
+			/* If we know the number of records on level 1, then
+			this number is the same as the number of pages on
+			level 0 (leaf). */
+			n_ordinary_leaf_pages = data->n_recs_on_level;
+		} else {
+			/* If we analyzed D ordinary leaf pages and found E
+			external pages in total linked from those D ordinary
+			leaf pages, then this means that the ratio
+			ordinary/external is D/E. Then the ratio ordinary/total
+			is D / (D + E). Knowing that the total number of pages
+			is T (including ordinary and external) then we estimate
+			that the total number of ordinary leaf pages is
+			T * D / (D + E). */
+			n_ordinary_leaf_pages
+				= index_stats.n_leaf_pages
+				* data->n_leaf_pages_to_analyze
+				/ (data->n_leaf_pages_to_analyze
+				   + data->n_external_pages_sum);
+		}
+
+		/* See REF01 for an explanation of the algorithm */
+		index_stats.stats[n_prefix - 1].n_diff_key_vals
+			= n_ordinary_leaf_pages
+
+			* data->n_diff_on_level
+			/ data->n_recs_on_level
+
+			* data->n_diff_all_analyzed_pages
+			/ data->n_leaf_pages_to_analyze;
+
+		index_stats.stats[n_prefix - 1].n_sample_sizes
+			= data->n_leaf_pages_to_analyze;
+
+		DEBUG_PRINTF("    %s(): n_diff=" UINT64PF
+			     " for n_prefix=" ULINTPF
+			     " (" ULINTPF
+			     " * " UINT64PF " / " UINT64PF
+			     " * " UINT64PF " / " UINT64PF ")\n",
+			     __func__,
+			     index_stats.stats[n_prefix - 1].n_diff_key_vals,
+			     n_prefix,
+			     index_stats.n_leaf_pages,
+			     data->n_diff_on_level,
+			     data->n_recs_on_level,
+			     data->n_diff_all_analyzed_pages,
+			     data->n_leaf_pages_to_analyze);
+	}
+}
+
+/** Calculates new statistics for a given index and saves them to the index
+members stat_n_diff_key_vals[], stat_n_sample_sizes[], stat_index_size and
+stat_n_leaf_pages. This function can be slow.
+@param[in]	index	index to analyze
+@return index stats */
+static index_stats_t dict_stats_analyze_index(dict_index_t* index)
+{
+	bool		level_is_analyzed;
+	ulint		n_uniq;
+	ulint		n_prefix;
+	ib_uint64_t	total_recs;
+	ib_uint64_t	total_pages;
+	mtr_t		mtr;
+	index_stats_t	result(index->n_uniq);
+	DBUG_ENTER("dict_stats_analyze_index");
+
+	DBUG_PRINT("info", ("index: %s, online status: %d", index->name(),
+			    dict_index_get_online_status(index)));
+
+	ut_ad(!index->table->stats_mutex_is_owner());
+	ut_ad(index->table->get_ref_count());
+
+	if (!index->is_btree()) {
+		DBUG_RETURN(result);
+	}
+
+	DEBUG_PRINTF("  %s(index=%s)\n", __func__, index->name());
+
+	mtr.start();
+	mtr_sx_lock_index(index, &mtr);
+	dberr_t err;
+	buf_block_t* root = btr_root_block_get(index, RW_SX_LATCH, &mtr, &err);
+	if (!root) {
+empty_index:
+		mtr.commit();
+		dict_stats_assert_initialized_index(index);
+		DBUG_RETURN(result);
+	}
+
+	uint16_t root_level = btr_page_get_level(root->page.frame);
+	mtr.x_lock_space(index->table->space);
+	ulint dummy, size;
+	result.index_size
+		= fseg_n_reserved_pages(*root, PAGE_HEADER + PAGE_BTR_SEG_LEAF
+					+ root->page.frame, &size, &mtr)
+		+ fseg_n_reserved_pages(*root, PAGE_HEADER + PAGE_BTR_SEG_TOP
+					+ root->page.frame, &dummy, &mtr);
+	result.n_leaf_pages = size ? size : 1;
+
+	const auto bulk_trx_id = index->table->bulk_trx_id;
+	if (bulk_trx_id && trx_sys.find(nullptr, bulk_trx_id, false)) {
+		result.set_bulk_operation();
+		goto empty_index;
+	}
+
+	mtr.commit();
+
+	mtr.start();
+	mtr_sx_lock_index(index, &mtr);
+
+	n_uniq = dict_index_get_n_unique(index);
+
+	/* If the tree has just one level (and one page) or if the user
+	has requested to sample too many pages then do full scan.
+
+	For each n-column prefix (for n=1..n_uniq) N_SAMPLE_PAGES(index)
+	will be sampled, so in total N_SAMPLE_PAGES(index) * n_uniq leaf
+	pages will be sampled. If that number is bigger than the total
+	number of leaf pages then do full scan of the leaf level instead
+	since it will be faster and will give better results. */
+
+	if (root_level == 0
+	    || N_SAMPLE_PAGES(index) * n_uniq > result.n_leaf_pages) {
+
+		if (root_level == 0) {
+			DEBUG_PRINTF("  %s(): just one page,"
+				     " doing full scan\n", __func__);
+		} else {
+			DEBUG_PRINTF("  %s(): too many pages requested for"
+				     " sampling, doing full scan\n", __func__);
+		}
+
+		/* do full scan of level 0; save results directly
+		into the index */
+
+		dict_stats_analyze_index_level(index,
+					       0 /* leaf level */,
+					       index->stat_n_diff_key_vals,
+					       &total_recs,
+					       &total_pages,
+					       NULL /* boundaries not needed */,
+					       &mtr);
+
+		mtr.commit();
+
+		index->table->stats_mutex_lock();
+		for (ulint i = 0; i < n_uniq; i++) {
+			result.stats[i].n_diff_key_vals = index->stat_n_diff_key_vals[i];
+			result.stats[i].n_sample_sizes = total_pages;
+			result.stats[i].n_non_null_key_vals = index->stat_n_non_null_key_vals[i];
+		}
+		result.n_leaf_pages = index->stat_n_leaf_pages;
+		index->table->stats_mutex_unlock();
+
+		DBUG_RETURN(result);
+	}
+
+	/* For each level that is being scanned in the btree, this contains the
+	number of different key values for all possible n-column prefixes. */
+	ib_uint64_t*	n_diff_on_level = UT_NEW_ARRAY(
+		ib_uint64_t, n_uniq, mem_key_dict_stats_n_diff_on_level);
+
+	/* For each level that is being scanned in the btree, this contains the
+	index of the last record from each group of equal records (when
+	comparing only the first n columns, n=1..n_uniq). */
+	boundaries_t*	n_diff_boundaries = UT_NEW_ARRAY_NOKEY(boundaries_t,
+							       n_uniq);
+
+	/* For each n-column prefix this array contains the input data that is
+	used to calculate dict_index_t::stat_n_diff_key_vals[]. */
+	n_diff_data_t*	n_diff_data = UT_NEW_ARRAY_NOKEY(n_diff_data_t, n_uniq);
+
+	/* total_recs is also used to estimate the number of pages on one
+	level below, so at the start we have 1 page (the root) */
+	total_recs = 1;
+
+	/* Here we use the following optimization:
+	If we find that level L is the first one (searching from the
+	root) that contains at least D distinct keys when looking at
+	the first n_prefix columns, then:
+	if we look at the first n_prefix-1 columns then the first
+	level that contains D distinct keys will be either L or a
+	lower one.
+	So if we find that the first level containing D distinct
+	keys (on n_prefix columns) is L, we continue from L when
+	searching for D distinct keys on n_prefix-1 columns. */
+	auto level = root_level;
+	level_is_analyzed = false;
+
+	for (n_prefix = n_uniq; n_prefix >= 1; n_prefix--) {
+
+		DEBUG_PRINTF("  %s(): searching level with >=%llu "
+			     "distinct records, n_prefix=" ULINTPF "\n",
+			     __func__, N_DIFF_REQUIRED(index), n_prefix);
+
+		/* Commit the mtr to release the tree S lock to allow
+		other threads to do some work too. */
+		mtr.commit();
+		mtr.start();
+		mtr_sx_lock_index(index, &mtr);
+		ut_ad(mtr.get_savepoint() == 1);
+		buf_block_t *root = btr_root_block_get(index, RW_S_LATCH,
+						       &mtr, &err);
+		if (!root || root_level != btr_page_get_level(root->page.frame)
+		    || index->table->bulk_trx_id != bulk_trx_id) {
+			/* Just quit if the tree has changed beyond
+			recognition here. The old stats from previous
+			runs will remain in the values that we have
+			not calculated yet. Initially when the index
+			object is created the stats members are given
+			some sensible values so leaving them untouched
+			here even the first time will not cause us to
+			read uninitialized memory later. */
+			break;
+		}
+
+		mtr.rollback_to_savepoint(1);
+
+		/* check whether we should pick the current level;
+		we pick level 1 even if it does not have enough
+		distinct records because we do not want to scan the
+		leaf level because it may contain too many records */
+		if (level_is_analyzed
+		    && (n_diff_on_level[n_prefix - 1] >= N_DIFF_REQUIRED(index)
+			|| level == 1)) {
+
+			goto found_level;
+		}
+
+		/* search for a level that contains enough distinct records */
+
+		if (level_is_analyzed && level > 1) {
+
+			/* if this does not hold we should be on
+			"found_level" instead of here */
+			ut_ad(n_diff_on_level[n_prefix - 1]
+			      < N_DIFF_REQUIRED(index));
+
+			level--;
+			level_is_analyzed = false;
+		}
+
+		/* descend into the tree, searching for "good enough" level */
+		for (;;) {
+
+			/* make sure we do not scan the leaf level
+			accidentally, it may contain too many pages */
+			ut_ad(level > 0);
+
+			/* scanning the same level twice is an optimization
+			bug */
+			ut_ad(!level_is_analyzed);
+
+			/* Do not scan if this would read too many pages.
+			Here we use the following fact:
+			the number of pages on level L equals the number
+			of records on level L+1, thus we deduce that the
+			following call would scan total_recs pages, because
+			total_recs is left from the previous iteration when
+			we scanned one level upper or we have not scanned any
+			levels yet in which case total_recs is 1. */
+			if (total_recs > N_SAMPLE_PAGES(index)) {
+
+				/* if the above cond is true then we are
+				not at the root level since on the root
+				level total_recs == 1 (set before we
+				enter the n-prefix loop) and cannot
+				be > N_SAMPLE_PAGES(index) */
+				ut_a(level != root_level);
+
+				/* step one level back and be satisfied with
+				whatever it contains */
+				level++;
+				level_is_analyzed = true;
+
+				break;
+			}
+
+			mtr.rollback_to_savepoint(1);
+			dict_stats_analyze_index_level(index,
+						       level,
+						       n_diff_on_level,
+						       &total_recs,
+						       &total_pages,
+						       n_diff_boundaries,
+						       &mtr);
+			mtr.rollback_to_savepoint(1);
+			level_is_analyzed = true;
+
+			if (level == 1
+			    || n_diff_on_level[n_prefix - 1]
+			    >= N_DIFF_REQUIRED(index)) {
+				/* we have reached the last level we could scan
+				or we found a good level with many distinct
+				records */
+				break;
+			}
+
+			level--;
+			level_is_analyzed = false;
+		}
+found_level:
+
+		DEBUG_PRINTF("  %s(): found level " ULINTPF
+			     " that has " UINT64PF
+			     " distinct records for n_prefix=" ULINTPF "\n",
+			     __func__, level, n_diff_on_level[n_prefix - 1],
+			     n_prefix);
+		/* here we are either on level 1 or the level that we are on
+		contains >= N_DIFF_REQUIRED distinct keys or we did not scan
+		deeper levels because they would contain too many pages */
+
+		ut_ad(level > 0);
+
+		ut_ad(level_is_analyzed);
+
+		/* if any of these is 0 then there is exactly one page in the
+		B-tree and it is empty and we should have done full scan and
+		should not be here */
+		ut_ad(total_recs > 0);
+		ut_ad(n_diff_on_level[n_prefix - 1] > 0);
+
+		ut_ad(N_SAMPLE_PAGES(index) > 0);
+
+		n_diff_data_t*	data = &n_diff_data[n_prefix - 1];
+
+		data->level = level;
+
+		data->n_recs_on_level = total_recs;
+
+		data->n_diff_on_level = n_diff_on_level[n_prefix - 1];
+
+		data->n_leaf_pages_to_analyze = std::min(
+			N_SAMPLE_PAGES(index),
+			n_diff_on_level[n_prefix - 1]);
+
+		/* pick some records from this level and dive below them for
+		the given n_prefix */
+
+		dict_stats_analyze_index_for_n_prefix(
+			index, n_prefix, &n_diff_boundaries[n_prefix - 1],
+			data, &mtr);
+	}
+
+	mtr.commit();
+
+	UT_DELETE_ARRAY(n_diff_boundaries);
+
+	UT_DELETE_ARRAY(n_diff_on_level);
+
+	/* n_prefix == 0 means that the above loop did not end up prematurely
+	due to tree being changed and so n_diff_data[] is set up. */
+	if (n_prefix == 0) {
+		dict_stats_index_set_n_diff(n_diff_data, result);
+	}
+
+	UT_DELETE_ARRAY(n_diff_data);
+
+	DBUG_RETURN(result);
+}
+
+/*********************************************************************//**
+Calculates new estimates for table and index statistics. This function
+is relatively slow and is used to calculate persistent statistics that
+will be saved on disk.
+@return DB_SUCCESS or error code
+@retval DB_SUCCESS_LOCKED_REC if the table under bulk insert operation */
+static
+dberr_t
+dict_stats_update_persistent(
+/*=========================*/
+	dict_table_t*	table)		/*!< in/out: table */
+{
+	dict_index_t*	index;
+
+	DEBUG_PRINTF("%s(table=%s)\n", __func__, table->name);
+
+	DEBUG_SYNC_C("dict_stats_update_persistent");
+
+	/* analyze the clustered index first */
+
+	index = dict_table_get_first_index(table);
+
+	if (index == NULL
+	    || index->is_corrupted()
+	    || (index->type | DICT_UNIQUE) != (DICT_CLUSTERED | DICT_UNIQUE)) {
+
+		/* Table definition is corrupt */
+		dict_stats_empty_table(table, true);
+
+		return(DB_CORRUPTION);
+	}
+
+	ut_ad(!dict_index_is_ibuf(index));
+	table->stats_mutex_lock();
+	dict_stats_empty_index(index, false);
+	table->stats_mutex_unlock();
+
+	index_stats_t stats = dict_stats_analyze_index(index);
+
+	if (stats.is_bulk_operation()) {
+		dict_stats_empty_table(table, false);
+		return DB_SUCCESS_LOCKED_REC;
+	}
+
+	table->stats_mutex_lock();
+	index->stat_index_size = stats.index_size;
+	index->stat_n_leaf_pages = stats.n_leaf_pages;
+	for (size_t i = 0; i < stats.stats.size(); ++i) {
+		index->stat_n_diff_key_vals[i] = stats.stats[i].n_diff_key_vals;
+		index->stat_n_sample_sizes[i] = stats.stats[i].n_sample_sizes;
+		index->stat_n_non_null_key_vals[i] = stats.stats[i].n_non_null_key_vals;
+	}
+
+	ulint	n_unique = dict_index_get_n_unique(index);
+
+	table->stat_n_rows = index->stat_n_diff_key_vals[n_unique - 1];
+
+	table->stat_clustered_index_size = index->stat_index_size;
+
+	/* analyze other indexes from the table, if any */
+
+	table->stat_sum_of_other_index_sizes = 0;
+
+	for (index = dict_table_get_next_index(index);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		if (!index->is_btree()) {
+			continue;
+		}
+
+		dict_stats_empty_index(index, false);
+
+		if (dict_stats_should_ignore_index(index)) {
+			continue;
+		}
+
+		table->stats_mutex_unlock();
+		stats = dict_stats_analyze_index(index);
+		table->stats_mutex_lock();
+
+		if (stats.is_bulk_operation()) {
+			table->stats_mutex_unlock();
+			dict_stats_empty_table(table, false);
+			return DB_SUCCESS_LOCKED_REC;
+		}
+
+		index->stat_index_size = stats.index_size;
+		index->stat_n_leaf_pages = stats.n_leaf_pages;
+
+		for (size_t i = 0; i < stats.stats.size(); ++i) {
+			index->stat_n_diff_key_vals[i]
+				= stats.stats[i].n_diff_key_vals;
+			index->stat_n_sample_sizes[i]
+				= stats.stats[i].n_sample_sizes;
+			index->stat_n_non_null_key_vals[i]
+				= stats.stats[i].n_non_null_key_vals;
+		}
+
+		table->stat_sum_of_other_index_sizes
+			+= index->stat_index_size;
+	}
+
+	table->stats_last_recalc = time(NULL);
+
+	table->stat_modified_counter = 0;
+
+	table->stat_initialized = TRUE;
+
+	dict_stats_assert_initialized(table);
+
+	table->stats_mutex_unlock();
+
+	return(DB_SUCCESS);
+}
+
+#include "mysql_com.h"
+/** Save an individual index's statistic into the persistent statistics
+storage.
+@param[in]	index			index to be updated
+@param[in]	last_update		timestamp of the stat
+@param[in]	stat_name		name of the stat
+@param[in]	stat_value		value of the stat
+@param[in]	sample_size		n pages sampled or NULL
+@param[in]	stat_description	description of the stat
+@param[in,out]	trx			transaction
+@return DB_SUCCESS or error code */
+dberr_t
+dict_stats_save_index_stat(
+	dict_index_t*	index,
+	time_t		last_update,
+	const char*	stat_name,
+	ib_uint64_t	stat_value,
+	ib_uint64_t*	sample_size,
+	const char*	stat_description,
+	trx_t*		trx)
+{
+	dberr_t		ret;
+	pars_info_t*	pinfo;
+	char		db_utf8[MAX_DB_UTF8_LEN];
+	char		table_utf8[MAX_TABLE_UTF8_LEN];
+
+	ut_ad(dict_sys.locked());
+
+	dict_fs2utf8(index->table->name.m_name, db_utf8, sizeof(db_utf8),
+		     table_utf8, sizeof(table_utf8));
+
+	pinfo = pars_info_create();
+	pars_info_add_str_literal(pinfo, "database_name", db_utf8);
+	pars_info_add_str_literal(pinfo, "table_name", table_utf8);
+	pars_info_add_str_literal(pinfo, "index_name", index->name);
+	MEM_CHECK_DEFINED(&last_update, 4);
+	pars_info_add_int4_literal(pinfo, "last_update", uint32(last_update));
+	MEM_CHECK_DEFINED(stat_name, strlen(stat_name));
+	pars_info_add_str_literal(pinfo, "stat_name", stat_name);
+	MEM_CHECK_DEFINED(&stat_value, 8);
+	pars_info_add_ull_literal(pinfo, "stat_value", stat_value);
+	if (sample_size != NULL) {
+		MEM_CHECK_DEFINED(sample_size, 8);
+		pars_info_add_ull_literal(pinfo, "sample_size", *sample_size);
+	} else {
+		pars_info_add_literal(pinfo, "sample_size", NULL,
+				      UNIV_SQL_NULL, DATA_FIXBINARY, 0);
+	}
+	pars_info_add_str_literal(pinfo, "stat_description",
+				  stat_description);
+
+	ret = dict_stats_exec_sql(
+		pinfo,
+		"PROCEDURE INDEX_STATS_SAVE () IS\n"
+		"BEGIN\n"
+
+		"DELETE FROM \"" INDEX_STATS_NAME "\"\n"
+		"WHERE\n"
+		"database_name = :database_name AND\n"
+		"table_name = :table_name AND\n"
+		"index_name = :index_name AND\n"
+		"stat_name = :stat_name;\n"
+
+		"INSERT INTO \"" INDEX_STATS_NAME "\"\n"
+		"VALUES\n"
+		"(\n"
+		":database_name,\n"
+		":table_name,\n"
+		":index_name,\n"
+		":last_update,\n"
+		":stat_name,\n"
+		":stat_value,\n"
+		":sample_size,\n"
+		":stat_description\n"
+		");\n"
+		"END;", trx);
+
+	if (UNIV_UNLIKELY(ret != DB_SUCCESS)) {
+		if (innodb_index_stats_not_found == false &&
+		    index->stats_error_printed == false) {
+		ib::error() << "Cannot save index statistics for table "
+			<< index->table->name
+			<< ", index " << index->name
+			<< ", stat name \"" << stat_name << "\": "
+			<< ret;
+			index->stats_error_printed = true;
+		}
+	}
+
+	return(ret);
+}
+
+/** Report an error if updating table statistics failed because
+.ibd file is missing, table decryption failed or table is corrupted.
+@param[in,out]	table	Table
+@param[in]	defragment	true if statistics is for defragment
+@retval DB_DECRYPTION_FAILED if decryption of the table failed
+@retval DB_TABLESPACE_DELETED if .ibd file is missing
+@retval DB_CORRUPTION if table is marked as corrupted */
+dberr_t
+dict_stats_report_error(dict_table_t* table, bool defragment)
+{
+	dberr_t		err;
+
+	const char*	df = defragment ? " defragment" : "";
+
+	if (!table->space) {
+		ib::warn() << "Cannot save" << df << " statistics for table "
+			   << table->name
+			   << " because the .ibd file is missing. "
+			   << TROUBLESHOOTING_MSG;
+		err = DB_TABLESPACE_DELETED;
+	} else {
+		ib::warn() << "Cannot save" << df << " statistics for table "
+			   << table->name
+			   << " because file "
+			   << table->space->chain.start->name
+			   << (table->corrupted
+			       ? " is corrupted."
+			       : " cannot be decrypted.");
+		err = table->corrupted ? DB_CORRUPTION : DB_DECRYPTION_FAILED;
+	}
+
+	dict_stats_empty_table(table, defragment);
+	return err;
+}
+
+/** Save the table's statistics into the persistent statistics storage.
+@param[in]	table_orig	table whose stats to save
+@param[in]	only_for_index	if this is non-NULL, then stats for indexes
+that are not equal to it will not be saved, if NULL, then all indexes' stats
+are saved
+@return DB_SUCCESS or error code */
+static
+dberr_t
+dict_stats_save(
+	dict_table_t*		table_orig,
+	const index_id_t*	only_for_index)
+{
+	pars_info_t*	pinfo;
+	char		db_utf8[MAX_DB_UTF8_LEN];
+	char		table_utf8[MAX_TABLE_UTF8_LEN];
+
+#ifdef ENABLED_DEBUG_SYNC
+	DBUG_EXECUTE_IF("dict_stats_save_exit_notify",
+	   SCOPE_EXIT([] {
+	       debug_sync_set_action(current_thd,
+	       STRING_WITH_LEN("now SIGNAL dict_stats_save_finished"));
+	    });
+	);
+#endif /* ENABLED_DEBUG_SYNC */
+
+	if (high_level_read_only) {
+		return DB_READ_ONLY;
+	}
+
+	if (!table_orig->is_readable()) {
+		return (dict_stats_report_error(table_orig));
+	}
+
+	THD* thd = current_thd;
+	MDL_ticket *mdl_table = nullptr, *mdl_index = nullptr;
+	dict_table_t* table_stats = dict_table_open_on_name(
+		TABLE_STATS_NAME, false, DICT_ERR_IGNORE_NONE);
+	if (table_stats) {
+		dict_sys.freeze(SRW_LOCK_CALL);
+		table_stats = dict_acquire_mdl_shared<false>(table_stats, thd,
+							     &mdl_table);
+		dict_sys.unfreeze();
+	}
+	if (!table_stats
+	    || strcmp(table_stats->name.m_name, TABLE_STATS_NAME)) {
+release_and_exit:
+		if (table_stats) {
+			dict_table_close(table_stats, false, thd, mdl_table);
+		}
+		return DB_STATS_DO_NOT_EXIST;
+	}
+
+	dict_table_t* index_stats = dict_table_open_on_name(
+		INDEX_STATS_NAME, false, DICT_ERR_IGNORE_NONE);
+	if (index_stats) {
+		dict_sys.freeze(SRW_LOCK_CALL);
+		index_stats = dict_acquire_mdl_shared<false>(index_stats, thd,
+							     &mdl_index);
+		dict_sys.unfreeze();
+	}
+	if (!index_stats) {
+		goto release_and_exit;
+	}
+	if (strcmp(index_stats->name.m_name, INDEX_STATS_NAME)) {
+		dict_table_close(index_stats, false, thd, mdl_index);
+		goto release_and_exit;
+	}
+
+	dict_table_t* table = dict_stats_snapshot_create(table_orig);
+
+	dict_fs2utf8(table->name.m_name, db_utf8, sizeof(db_utf8),
+		     table_utf8, sizeof(table_utf8));
+	const time_t now = time(NULL);
+	trx_t*	trx = trx_create();
+	trx->mysql_thd = thd;
+	trx_start_internal(trx);
+	dberr_t ret = trx->read_only
+		? DB_READ_ONLY
+		: lock_table_for_trx(table_stats, trx, LOCK_X);
+	if (ret == DB_SUCCESS) {
+		ret = lock_table_for_trx(index_stats, trx, LOCK_X);
+	}
+	if (ret != DB_SUCCESS) {
+		if (trx->state != TRX_STATE_NOT_STARTED) {
+			trx->commit();
+		}
+		goto unlocked_free_and_exit;
+	}
+
+	pinfo = pars_info_create();
+
+	pars_info_add_str_literal(pinfo, "database_name", db_utf8);
+	pars_info_add_str_literal(pinfo, "table_name", table_utf8);
+	pars_info_add_int4_literal(pinfo, "last_update", uint32(now));
+	pars_info_add_ull_literal(pinfo, "n_rows", table->stat_n_rows);
+	pars_info_add_ull_literal(pinfo, "clustered_index_size",
+		table->stat_clustered_index_size);
+	pars_info_add_ull_literal(pinfo, "sum_of_other_index_sizes",
+		table->stat_sum_of_other_index_sizes);
+
+	dict_sys.lock(SRW_LOCK_CALL);
+	trx->dict_operation_lock_mode = true;
+
+	ret = dict_stats_exec_sql(
+		pinfo,
+		"PROCEDURE TABLE_STATS_SAVE () IS\n"
+		"BEGIN\n"
+
+		"DELETE FROM \"" TABLE_STATS_NAME "\"\n"
+		"WHERE\n"
+		"database_name = :database_name AND\n"
+		"table_name = :table_name;\n"
+
+		"INSERT INTO \"" TABLE_STATS_NAME "\"\n"
+		"VALUES\n"
+		"(\n"
+		":database_name,\n"
+		":table_name,\n"
+		":last_update,\n"
+		":n_rows,\n"
+		":clustered_index_size,\n"
+		":sum_of_other_index_sizes\n"
+		");\n"
+		"END;", trx);
+
+	if (UNIV_UNLIKELY(ret != DB_SUCCESS)) {
+		ib::error() << "Cannot save table statistics for table "
+			<< table->name << ": " << ret;
+rollback_and_exit:
+		trx->rollback();
+free_and_exit:
+		trx->dict_operation_lock_mode = false;
+		dict_sys.unlock();
+unlocked_free_and_exit:
+		trx->free();
+		dict_stats_snapshot_free(table);
+		dict_table_close(table_stats, false, thd, mdl_table);
+		dict_table_close(index_stats, false, thd, mdl_index);
+		return ret;
+	}
+
+	dict_index_t*	index;
+	index_map_t	indexes(
+		(ut_strcmp_functor()),
+		index_map_t_allocator(mem_key_dict_stats_index_map_t));
+
+	/* Below we do all the modifications in innodb_index_stats in a single
+	transaction for performance reasons. Modifying more than one row in a
+	single transaction may deadlock with other transactions if they
+	lock the rows in different order. Other transaction could be for
+	example when we DROP a table and do
+	DELETE FROM innodb_index_stats WHERE database_name = '...'
+	AND table_name = '...'; which will affect more than one row. To
+	prevent deadlocks we always lock the rows in the same order - the
+	order of the PK, which is (database_name, table_name, index_name,
+	stat_name). This is why below we sort the indexes by name and then
+	for each index, do the mods ordered by stat_name. */
+
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+
+		indexes[index->name] = index;
+	}
+
+	index_map_t::const_iterator	it;
+
+	for (it = indexes.begin(); it != indexes.end(); ++it) {
+
+		index = it->second;
+
+		if (only_for_index != NULL && index->id != *only_for_index) {
+			continue;
+		}
+
+		if (dict_stats_should_ignore_index(index)) {
+			continue;
+		}
+
+		ut_ad(!dict_index_is_ibuf(index));
+
+		for (unsigned i = 0; i < index->n_uniq; i++) {
+
+			char	stat_name[16];
+			char	stat_description[1024];
+
+			snprintf(stat_name, sizeof(stat_name),
+				 "n_diff_pfx%02u", i + 1);
+
+			/* craft a string that contains the column names */
+			snprintf(stat_description, sizeof(stat_description),
+				 "%s", index->fields[0].name());
+			for (unsigned j = 1; j <= i; j++) {
+				size_t	len;
+
+				len = strlen(stat_description);
+
+				snprintf(stat_description + len,
+					 sizeof(stat_description) - len,
+					 ",%s", index->fields[j].name());
+			}
+
+			ret = dict_stats_save_index_stat(
+				index, now, stat_name,
+				index->stat_n_diff_key_vals[i],
+				&index->stat_n_sample_sizes[i],
+				stat_description, trx);
+
+			if (ret != DB_SUCCESS) {
+				goto rollback_and_exit;
+			}
+		}
+
+		ret = dict_stats_save_index_stat(index, now, "n_leaf_pages",
+						 index->stat_n_leaf_pages,
+						 NULL,
+						 "Number of leaf pages "
+						 "in the index", trx);
+		if (ret != DB_SUCCESS) {
+			goto rollback_and_exit;
+		}
+
+		ret = dict_stats_save_index_stat(index, now, "size",
+						 index->stat_index_size,
+						 NULL,
+						 "Number of pages "
+						 "in the index", trx);
+		if (ret != DB_SUCCESS) {
+			goto rollback_and_exit;
+		}
+	}
+
+	ret= trx->bulk_insert_apply();
+	if (ret != DB_SUCCESS) {
+		goto rollback_and_exit;
+	}
+
+	trx->commit();
+	goto free_and_exit;
+}
+
+/*********************************************************************//**
+Called for the row that is selected by
+SELECT ... FROM mysql.innodb_table_stats WHERE table='...'
+The second argument is a pointer to the table and the fetched stats are
+written to it.
+@return non-NULL dummy */
+static
+ibool
+dict_stats_fetch_table_stats_step(
+/*==============================*/
+	void*	node_void,	/*!< in: select node */
+	void*	table_void)	/*!< out: table */
+{
+	sel_node_t*	node = (sel_node_t*) node_void;
+	dict_table_t*	table = (dict_table_t*) table_void;
+	que_common_t*	cnode;
+	int		i;
+
+	/* this should loop exactly 3 times - for
+	n_rows,clustered_index_size,sum_of_other_index_sizes */
+	for (cnode = static_cast<que_common_t*>(node->select_list), i = 0;
+	     cnode != NULL;
+	     cnode = static_cast<que_common_t*>(que_node_get_next(cnode)),
+	     i++) {
+
+		const byte*	data;
+		dfield_t*	dfield = que_node_get_val(cnode);
+		dtype_t*	type = dfield_get_type(dfield);
+		ulint		len = dfield_get_len(dfield);
+
+		data = static_cast<const byte*>(dfield_get_data(dfield));
+
+		switch (i) {
+		case 0: /* mysql.innodb_table_stats.n_rows */
+
+			ut_a(dtype_get_mtype(type) == DATA_INT);
+			ut_a(len == 8);
+
+			table->stat_n_rows = mach_read_from_8(data);
+
+			break;
+
+		case 1: /* mysql.innodb_table_stats.clustered_index_size */
+
+			ut_a(dtype_get_mtype(type) == DATA_INT);
+			ut_a(len == 8);
+
+			table->stat_clustered_index_size
+				= (ulint) mach_read_from_8(data);
+
+			break;
+
+		case 2: /* mysql.innodb_table_stats.sum_of_other_index_sizes */
+
+			ut_a(dtype_get_mtype(type) == DATA_INT);
+			ut_a(len == 8);
+
+			table->stat_sum_of_other_index_sizes
+				= (ulint) mach_read_from_8(data);
+
+			break;
+
+		default:
+
+			/* someone changed SELECT
+			n_rows,clustered_index_size,sum_of_other_index_sizes
+			to select more columns from innodb_table_stats without
+			adjusting here */
+			ut_error;
+		}
+	}
+
+	/* if i < 3 this means someone changed the
+	SELECT n_rows,clustered_index_size,sum_of_other_index_sizes
+	to select less columns from innodb_table_stats without adjusting here;
+	if i > 3 we would have ut_error'ed earlier */
+	ut_a(i == 3 /*n_rows,clustered_index_size,sum_of_other_index_sizes*/);
+
+	/* XXX this is not used but returning non-NULL is necessary */
+	return(TRUE);
+}
+
+/** Aux struct used to pass a table and a boolean to
+dict_stats_fetch_index_stats_step(). */
+struct index_fetch_t {
+	dict_table_t*	table;	/*!< table whose indexes are to be modified */
+	bool		stats_were_modified; /*!< will be set to true if at
+				least one index stats were modified */
+};
+
+/*********************************************************************//**
+Called for the rows that are selected by
+SELECT ... FROM mysql.innodb_index_stats WHERE table='...'
+The second argument is a pointer to the table and the fetched stats are
+written to its indexes.
+Let a table has N indexes and each index has Ui unique columns for i=1..N,
+then mysql.innodb_index_stats will have SUM(Ui) i=1..N rows for that table.
+So this function will be called SUM(Ui) times where SUM(Ui) is of magnitude
+N*AVG(Ui). In each call it searches for the currently fetched index into
+table->indexes linearly, assuming this list is not sorted. Thus, overall,
+fetching all indexes' stats from mysql.innodb_index_stats is O(N^2) where N
+is the number of indexes.
+This can be improved if we sort table->indexes in a temporary area just once
+and then search in that sorted list. Then the complexity will be O(N*log(N)).
+We assume a table will not have more than 100 indexes, so we go with the
+simpler N^2 algorithm.
+@return non-NULL dummy */
+static
+ibool
+dict_stats_fetch_index_stats_step(
+/*==============================*/
+	void*	node_void,	/*!< in: select node */
+	void*	arg_void)	/*!< out: table + a flag that tells if we
+				modified anything */
+{
+	sel_node_t*	node = (sel_node_t*) node_void;
+	index_fetch_t*	arg = (index_fetch_t*) arg_void;
+	dict_table_t*	table = arg->table;
+	dict_index_t*	index = NULL;
+	que_common_t*	cnode;
+	const char*	stat_name = NULL;
+	ulint		stat_name_len = ULINT_UNDEFINED;
+	ib_uint64_t	stat_value = UINT64_UNDEFINED;
+	ib_uint64_t	sample_size = UINT64_UNDEFINED;
+	int		i;
+
+	/* this should loop exactly 4 times - for the columns that
+	were selected: index_name,stat_name,stat_value,sample_size */
+	for (cnode = static_cast<que_common_t*>(node->select_list), i = 0;
+	     cnode != NULL;
+	     cnode = static_cast<que_common_t*>(que_node_get_next(cnode)),
+	     i++) {
+
+		const byte*	data;
+		dfield_t*	dfield = que_node_get_val(cnode);
+		dtype_t*	type = dfield_get_type(dfield);
+		ulint		len = dfield_get_len(dfield);
+
+		data = static_cast<const byte*>(dfield_get_data(dfield));
+
+		switch (i) {
+		case 0: /* mysql.innodb_index_stats.index_name */
+
+			ut_a(dtype_get_mtype(type) == DATA_VARMYSQL);
+
+			/* search for index in table's indexes whose name
+			matches data; the fetched index name is in data,
+			has no terminating '\0' and has length len */
+			for (index = dict_table_get_first_index(table);
+			     index != NULL;
+			     index = dict_table_get_next_index(index)) {
+
+				if (index->is_committed()
+				    && strlen(index->name) == len
+				    && memcmp(index->name, data, len) == 0) {
+					/* the corresponding index was found */
+					break;
+				}
+			}
+
+			/* if index is NULL here this means that
+			mysql.innodb_index_stats contains more rows than the
+			number of indexes in the table; this is ok, we just
+			return ignoring those extra rows; in other words
+			dict_stats_fetch_index_stats_step() has been called
+			for a row from index_stats with unknown index_name
+			column */
+			if (index == NULL) {
+
+				return(TRUE);
+			}
+
+			break;
+
+		case 1: /* mysql.innodb_index_stats.stat_name */
+
+			ut_a(dtype_get_mtype(type) == DATA_VARMYSQL);
+
+			ut_a(index != NULL);
+
+			stat_name = (const char*) data;
+			stat_name_len = len;
+
+			break;
+
+		case 2: /* mysql.innodb_index_stats.stat_value */
+
+			ut_a(dtype_get_mtype(type) == DATA_INT);
+			ut_a(len == 8);
+
+			ut_a(index != NULL);
+			ut_a(stat_name != NULL);
+			ut_a(stat_name_len != ULINT_UNDEFINED);
+
+			stat_value = mach_read_from_8(data);
+
+			break;
+
+		case 3: /* mysql.innodb_index_stats.sample_size */
+
+			ut_a(dtype_get_mtype(type) == DATA_INT);
+			ut_a(len == 8 || len == UNIV_SQL_NULL);
+
+			ut_a(index != NULL);
+			ut_a(stat_name != NULL);
+			ut_a(stat_name_len != ULINT_UNDEFINED);
+			ut_a(stat_value != UINT64_UNDEFINED);
+
+			if (len == UNIV_SQL_NULL) {
+				break;
+			}
+			/* else */
+
+			sample_size = mach_read_from_8(data);
+
+			break;
+
+		default:
+
+			/* someone changed
+			SELECT index_name,stat_name,stat_value,sample_size
+			to select more columns from innodb_index_stats without
+			adjusting here */
+			ut_error;
+		}
+	}
+
+	/* if i < 4 this means someone changed the
+	SELECT index_name,stat_name,stat_value,sample_size
+	to select less columns from innodb_index_stats without adjusting here;
+	if i > 4 we would have ut_error'ed earlier */
+	ut_a(i == 4 /* index_name,stat_name,stat_value,sample_size */);
+
+	ut_a(index != NULL);
+	ut_a(stat_name != NULL);
+	ut_a(stat_name_len != ULINT_UNDEFINED);
+	ut_a(stat_value != UINT64_UNDEFINED);
+	/* sample_size could be UINT64_UNDEFINED here, if it is NULL */
+
+#define PFX	"n_diff_pfx"
+#define PFX_LEN	10
+
+	if (stat_name_len == 4 /* strlen("size") */
+	    && strncasecmp("size", stat_name, stat_name_len) == 0) {
+		index->stat_index_size = (ulint) stat_value;
+		arg->stats_were_modified = true;
+	} else if (stat_name_len == 12 /* strlen("n_leaf_pages") */
+		   && strncasecmp("n_leaf_pages", stat_name, stat_name_len)
+		   == 0) {
+		index->stat_n_leaf_pages = (ulint) stat_value;
+		arg->stats_were_modified = true;
+	} else if (stat_name_len == 12 /* strlen("n_page_split") */
+		   && strncasecmp("n_page_split", stat_name, stat_name_len)
+		      == 0) {
+		index->stat_defrag_n_page_split = (ulint) stat_value;
+		arg->stats_were_modified = true;
+	} else if (stat_name_len == 13 /* strlen("n_pages_freed") */
+		   && strncasecmp("n_pages_freed", stat_name, stat_name_len)
+		      == 0) {
+		index->stat_defrag_n_pages_freed = (ulint) stat_value;
+		arg->stats_were_modified = true;
+	} else if (stat_name_len > PFX_LEN /* e.g. stat_name=="n_diff_pfx01" */
+		   && strncasecmp(PFX, stat_name, PFX_LEN) == 0) {
+
+		const char*	num_ptr;
+		unsigned long	n_pfx;
+
+		/* point num_ptr into "1" from "n_diff_pfx12..." */
+		num_ptr = stat_name + PFX_LEN;
+
+		/* stat_name should have exactly 2 chars appended to PFX
+		and they should be digits */
+		if (stat_name_len != PFX_LEN + 2
+		    || num_ptr[0] < '0' || num_ptr[0] > '9'
+		    || num_ptr[1] < '0' || num_ptr[1] > '9') {
+
+			char	db_utf8[MAX_DB_UTF8_LEN];
+			char	table_utf8[MAX_TABLE_UTF8_LEN];
+
+			dict_fs2utf8(table->name.m_name,
+				     db_utf8, sizeof(db_utf8),
+				     table_utf8, sizeof(table_utf8));
+
+			ib::info	out;
+			out << "Ignoring strange row from "
+				<< INDEX_STATS_NAME_PRINT << " WHERE"
+				" database_name = '" << db_utf8
+				<< "' AND table_name = '" << table_utf8
+				<< "' AND index_name = '" << index->name()
+				<< "' AND stat_name = '";
+			out.write(stat_name, stat_name_len);
+			out << "'; because stat_name is malformed";
+			return(TRUE);
+		}
+		/* else */
+
+		/* extract 12 from "n_diff_pfx12..." into n_pfx
+		note that stat_name does not have a terminating '\0' */
+		n_pfx = ulong(num_ptr[0] - '0') * 10 + ulong(num_ptr[1] - '0');
+
+		ulint	n_uniq = index->n_uniq;
+
+		if (n_pfx == 0 || n_pfx > n_uniq) {
+
+			char	db_utf8[MAX_DB_UTF8_LEN];
+			char	table_utf8[MAX_TABLE_UTF8_LEN];
+
+			dict_fs2utf8(table->name.m_name,
+				     db_utf8, sizeof(db_utf8),
+				     table_utf8, sizeof(table_utf8));
+
+			ib::info	out;
+			out << "Ignoring strange row from "
+				<< INDEX_STATS_NAME_PRINT << " WHERE"
+				" database_name = '" << db_utf8
+				<< "' AND table_name = '" << table_utf8
+				<< "' AND index_name = '" << index->name()
+				<< "' AND stat_name = '";
+			out.write(stat_name, stat_name_len);
+			out << "'; because stat_name is out of range, the index"
+				" has " << n_uniq << " unique columns";
+
+			return(TRUE);
+		}
+		/* else */
+
+		index->stat_n_diff_key_vals[n_pfx - 1] = stat_value;
+
+		if (sample_size != UINT64_UNDEFINED) {
+			index->stat_n_sample_sizes[n_pfx - 1] = sample_size;
+		} else {
+			/* hmm, strange... the user must have UPDATEd the
+			table manually and SET sample_size = NULL */
+			index->stat_n_sample_sizes[n_pfx - 1] = 0;
+		}
+
+		index->stat_n_non_null_key_vals[n_pfx - 1] = 0;
+
+		arg->stats_were_modified = true;
+	} else {
+		/* silently ignore rows with unknown stat_name, the
+		user may have developed her own stats */
+	}
+
+	/* XXX this is not used but returning non-NULL is necessary */
+	return(TRUE);
+}
+
+/*********************************************************************//**
+Read table's statistics from the persistent statistics storage.
+@return DB_SUCCESS or error code */
+static
+dberr_t
+dict_stats_fetch_from_ps(
+/*=====================*/
+	dict_table_t*	table)	/*!< in/out: table */
+{
+	index_fetch_t	index_fetch_arg;
+	trx_t*		trx;
+	pars_info_t*	pinfo;
+	dberr_t		ret;
+	char		db_utf8[MAX_DB_UTF8_LEN];
+	char		table_utf8[MAX_TABLE_UTF8_LEN];
+
+	/* Initialize all stats to dummy values before fetching because if
+	the persistent storage contains incomplete stats (e.g. missing stats
+	for some index) then we would end up with (partially) uninitialized
+	stats. */
+	dict_stats_empty_table(table, true);
+
+	THD* thd = current_thd;
+	MDL_ticket *mdl_table = nullptr, *mdl_index = nullptr;
+	dict_table_t* table_stats = dict_table_open_on_name(
+		TABLE_STATS_NAME, false, DICT_ERR_IGNORE_NONE);
+	if (table_stats) {
+		dict_sys.freeze(SRW_LOCK_CALL);
+		table_stats = dict_acquire_mdl_shared<false>(table_stats, thd,
+							     &mdl_table);
+		dict_sys.unfreeze();
+	}
+	if (!table_stats
+	    || strcmp(table_stats->name.m_name, TABLE_STATS_NAME)) {
+release_and_exit:
+		if (table_stats) {
+			dict_table_close(table_stats, false, thd, mdl_table);
+		}
+		return DB_STATS_DO_NOT_EXIST;
+	}
+
+	dict_table_t* index_stats = dict_table_open_on_name(
+		INDEX_STATS_NAME, false, DICT_ERR_IGNORE_NONE);
+	if (index_stats) {
+		dict_sys.freeze(SRW_LOCK_CALL);
+		index_stats = dict_acquire_mdl_shared<false>(index_stats, thd,
+							     &mdl_index);
+		dict_sys.unfreeze();
+	}
+	if (!index_stats) {
+		goto release_and_exit;
+	}
+	if (strcmp(index_stats->name.m_name, INDEX_STATS_NAME)) {
+		dict_table_close(index_stats, false, thd, mdl_index);
+		goto release_and_exit;
+	}
+
+	trx = trx_create();
+
+	trx_start_internal_read_only(trx);
+
+	dict_fs2utf8(table->name.m_name, db_utf8, sizeof(db_utf8),
+		     table_utf8, sizeof(table_utf8));
+
+	pinfo = pars_info_create();
+
+	pars_info_add_str_literal(pinfo, "database_name", db_utf8);
+
+	pars_info_add_str_literal(pinfo, "table_name", table_utf8);
+
+	pars_info_bind_function(pinfo,
+			       "fetch_table_stats_step",
+			       dict_stats_fetch_table_stats_step,
+			       table);
+
+	index_fetch_arg.table = table;
+	index_fetch_arg.stats_were_modified = false;
+	pars_info_bind_function(pinfo,
+			        "fetch_index_stats_step",
+			        dict_stats_fetch_index_stats_step,
+			        &index_fetch_arg);
+	dict_sys.lock(SRW_LOCK_CALL); /* FIXME: remove this */
+	ret = que_eval_sql(pinfo,
+			   "PROCEDURE FETCH_STATS () IS\n"
+			   "found INT;\n"
+			   "DECLARE FUNCTION fetch_table_stats_step;\n"
+			   "DECLARE FUNCTION fetch_index_stats_step;\n"
+			   "DECLARE CURSOR table_stats_cur IS\n"
+			   "  SELECT\n"
+			   /* if you change the selected fields, be
+			   sure to adjust
+			   dict_stats_fetch_table_stats_step() */
+			   "  n_rows,\n"
+			   "  clustered_index_size,\n"
+			   "  sum_of_other_index_sizes\n"
+			   "  FROM \"" TABLE_STATS_NAME "\"\n"
+			   "  WHERE\n"
+			   "  database_name = :database_name AND\n"
+			   "  table_name = :table_name;\n"
+			   "DECLARE CURSOR index_stats_cur IS\n"
+			   "  SELECT\n"
+			   /* if you change the selected fields, be
+			   sure to adjust
+			   dict_stats_fetch_index_stats_step() */
+			   "  index_name,\n"
+			   "  stat_name,\n"
+			   "  stat_value,\n"
+			   "  sample_size\n"
+			   "  FROM \"" INDEX_STATS_NAME "\"\n"
+			   "  WHERE\n"
+			   "  database_name = :database_name AND\n"
+			   "  table_name = :table_name;\n"
+
+			   "BEGIN\n"
+
+			   "OPEN table_stats_cur;\n"
+			   "FETCH table_stats_cur INTO\n"
+			   "  fetch_table_stats_step();\n"
+			   "IF (SQL % NOTFOUND) THEN\n"
+			   "  CLOSE table_stats_cur;\n"
+			   "  RETURN;\n"
+			   "END IF;\n"
+			   "CLOSE table_stats_cur;\n"
+
+			   "OPEN index_stats_cur;\n"
+			   "found := 1;\n"
+			   "WHILE found = 1 LOOP\n"
+			   "  FETCH index_stats_cur INTO\n"
+			   "    fetch_index_stats_step();\n"
+			   "  IF (SQL % NOTFOUND) THEN\n"
+			   "    found := 0;\n"
+			   "  END IF;\n"
+			   "END LOOP;\n"
+			   "CLOSE index_stats_cur;\n"
+
+			   "END;", trx);
+	/* pinfo is freed by que_eval_sql() */
+	dict_sys.unlock();
+
+	dict_table_close(table_stats, false, thd, mdl_table);
+	dict_table_close(index_stats, false, thd, mdl_index);
+
+	trx_commit_for_mysql(trx);
+
+	trx->free();
+
+	if (!index_fetch_arg.stats_were_modified) {
+		return(DB_STATS_DO_NOT_EXIST);
+	}
+
+	return(ret);
+}
+
+/*********************************************************************//**
+Clear defragmentation stats modified counter for all indices in table. */
+static
+void
+dict_stats_empty_defrag_modified_counter(
+	dict_table_t*	table)	/*!< in: table */
+{
+	dict_index_t*	index;
+	ut_a(table);
+	for (index = dict_table_get_first_index(table);
+	     index != NULL;
+	     index = dict_table_get_next_index(index)) {
+		index->stat_defrag_modified_counter = 0;
+	}
+}
+
+/*********************************************************************//**
+Fetches or calculates new estimates for index statistics. */
+void
+dict_stats_update_for_index(
+/*========================*/
+	dict_index_t*	index)	/*!< in/out: index */
+{
+	DBUG_ENTER("dict_stats_update_for_index");
+
+	if (dict_stats_is_persistent_enabled(index->table)) {
+
+		if (dict_stats_persistent_storage_check(false)) {
+			index_stats_t stats = dict_stats_analyze_index(index);
+			index->table->stats_mutex_lock();
+			index->stat_index_size = stats.index_size;
+			index->stat_n_leaf_pages = stats.n_leaf_pages;
+			for (size_t i = 0; i < stats.stats.size(); ++i) {
+				index->stat_n_diff_key_vals[i]
+					= stats.stats[i].n_diff_key_vals;
+				index->stat_n_sample_sizes[i]
+					= stats.stats[i].n_sample_sizes;
+				index->stat_n_non_null_key_vals[i]
+					= stats.stats[i].n_non_null_key_vals;
+			}
+			index->table->stat_sum_of_other_index_sizes
+				+= index->stat_index_size;
+			index->table->stats_mutex_unlock();
+
+			dict_stats_save(index->table, &index->id);
+			DBUG_VOID_RETURN;
+		}
+		/* else */
+
+		if (innodb_index_stats_not_found == false &&
+		    index->stats_error_printed == false) {
+			/* Fall back to transient stats since the persistent
+			storage is not present or is corrupted */
+
+		ib::info() << "Recalculation of persistent statistics"
+			" requested for table " << index->table->name
+			<< " index " << index->name
+			<< " but the required"
+			" persistent statistics storage is not present or is"
+			" corrupted. Using transient stats instead.";
+			index->stats_error_printed = false;
+		}
+	}
+
+	dict_stats_update_transient_for_index(index);
+
+	DBUG_VOID_RETURN;
+}
+
+/*********************************************************************//**
+Calculates new estimates for table and index statistics. The statistics
+are used in query optimization.
+@return DB_SUCCESS or error code
+@retval DB_SUCCESS_LOCKED_REC if the table under bulk insert operation */
+dberr_t
+dict_stats_update(
+/*==============*/
+	dict_table_t*		table,	/*!< in/out: table */
+	dict_stats_upd_option_t	stats_upd_option)
+					/*!< in: whether to (re) calc
+					the stats or to fetch them from
+					the persistent statistics
+					storage */
+{
+	ut_ad(!table->stats_mutex_is_owner());
+
+	if (!table->is_readable()) {
+		return (dict_stats_report_error(table));
+	} else if (srv_force_recovery >= SRV_FORCE_NO_UNDO_LOG_SCAN) {
+		/* If we have set a high innodb_force_recovery level, do
+		not calculate statistics, as a badly corrupted index can
+		cause a crash in it. */
+		dict_stats_empty_table(table, false);
+		return(DB_SUCCESS);
+	}
+
+	if (trx_id_t bulk_trx_id = table->bulk_trx_id) {
+		if (trx_sys.find(nullptr, bulk_trx_id, false)) {
+			dict_stats_empty_table(table, false);
+			return DB_SUCCESS_LOCKED_REC;
+		}
+	}
+
+	switch (stats_upd_option) {
+	case DICT_STATS_RECALC_PERSISTENT:
+
+		if (srv_read_only_mode) {
+			goto transient;
+		}
+
+		/* Persistent recalculation requested, called from
+		1) ANALYZE TABLE, or
+		2) the auto recalculation background thread, or
+		3) open table if stats do not exist on disk and auto recalc
+		   is enabled */
+
+		/* InnoDB internal tables (e.g. SYS_TABLES) cannot have
+		persistent stats enabled */
+		ut_a(strchr(table->name.m_name, '/') != NULL);
+
+		/* check if the persistent statistics storage exists
+		before calling the potentially slow function
+		dict_stats_update_persistent(); that is a
+		prerequisite for dict_stats_save() succeeding */
+		if (dict_stats_persistent_storage_check(false)) {
+
+			dberr_t	err;
+
+			err = dict_stats_update_persistent(table);
+
+			if (err != DB_SUCCESS) {
+				return(err);
+			}
+
+			err = dict_stats_save(table, NULL);
+
+			return(err);
+		}
+
+		/* Fall back to transient stats since the persistent
+		storage is not present or is corrupted */
+
+		if (innodb_table_stats_not_found == false &&
+		    table->stats_error_printed == false) {
+		ib::warn() << "Recalculation of persistent statistics"
+			" requested for table "
+			<< table->name
+			<< " but the required persistent"
+			" statistics storage is not present or is corrupted."
+			" Using transient stats instead.";
+			table->stats_error_printed = true;
+		}
+
+		goto transient;
+
+	case DICT_STATS_RECALC_TRANSIENT:
+
+		goto transient;
+
+	case DICT_STATS_EMPTY_TABLE:
+
+		dict_stats_empty_table(table, true);
+
+		/* If table is using persistent stats,
+		then save the stats on disk */
+
+		if (dict_stats_is_persistent_enabled(table)) {
+
+			if (dict_stats_persistent_storage_check(false)) {
+
+				return(dict_stats_save(table, NULL));
+			}
+
+			return(DB_STATS_DO_NOT_EXIST);
+		}
+
+		return(DB_SUCCESS);
+
+	case DICT_STATS_FETCH_ONLY_IF_NOT_IN_MEMORY:
+
+		/* fetch requested, either fetch from persistent statistics
+		storage or use the old method */
+
+		if (table->stat_initialized) {
+			return(DB_SUCCESS);
+		}
+
+		/* InnoDB internal tables (e.g. SYS_TABLES) cannot have
+		persistent stats enabled */
+		ut_a(strchr(table->name.m_name, '/') != NULL);
+
+		if (!dict_stats_persistent_storage_check(false)) {
+			/* persistent statistics storage does not exist
+			or is corrupted, calculate the transient stats */
+
+			if (innodb_table_stats_not_found == false &&
+			    table->stats_error_printed == false &&
+			    !opt_bootstrap) {
+				ib::error() << "Fetch of persistent statistics"
+					" requested for table "
+					<< table->name
+					<< " but the required system tables "
+					<< TABLE_STATS_NAME_PRINT
+					<< " and " << INDEX_STATS_NAME_PRINT
+					<< " are not present or have unexpected"
+					" structure. Using transient stats instead.";
+					table->stats_error_printed = true;
+			}
+
+			goto transient;
+		}
+
+		dict_table_t*	t;
+
+		/* Create a dummy table object with the same name and
+		indexes, suitable for fetching the stats into it. */
+		t = dict_stats_table_clone_create(table);
+
+		dberr_t	err = dict_stats_fetch_from_ps(t);
+
+		t->stats_last_recalc = table->stats_last_recalc;
+		t->stat_modified_counter = 0;
+		dict_stats_empty_defrag_modified_counter(t);
+
+		switch (err) {
+		case DB_SUCCESS:
+
+			table->stats_mutex_lock();
+			/* t is localized to this thread so no need to
+			take stats mutex lock (limiting it to debug only) */
+			ut_d(t->stats_mutex_lock());
+
+			/* Pass reset_ignored_indexes=true as parameter
+			to dict_stats_copy. This will cause statictics
+			for corrupted indexes to be set to empty values */
+			dict_stats_copy(table, t, true);
+
+			dict_stats_assert_initialized(table);
+
+			ut_d(t->stats_mutex_unlock());
+			table->stats_mutex_unlock();
+
+			dict_stats_table_clone_free(t);
+
+			return(DB_SUCCESS);
+		case DB_STATS_DO_NOT_EXIST:
+
+			dict_stats_table_clone_free(t);
+
+			if (srv_read_only_mode) {
+				goto transient;
+			}
+
+			if (dict_stats_auto_recalc_is_enabled(table)) {
+				return(dict_stats_update(
+						table,
+						DICT_STATS_RECALC_PERSISTENT));
+			}
+
+			ib::info() << "Trying to use table " << table->name
+				<< " which has persistent statistics enabled,"
+				" but auto recalculation turned off and the"
+				" statistics do not exist in "
+				TABLE_STATS_NAME_PRINT
+				" and " INDEX_STATS_NAME_PRINT
+				". Please either run \"ANALYZE TABLE "
+				<< table->name << ";\" manually or enable the"
+				" auto recalculation with \"ALTER TABLE "
+				<< table->name << " STATS_AUTO_RECALC=1;\"."
+				" InnoDB will now use transient statistics for "
+				<< table->name << ".";
+
+			goto transient;
+		default:
+
+			dict_stats_table_clone_free(t);
+
+			if (innodb_table_stats_not_found == false &&
+			    table->stats_error_printed == false) {
+				ib::error() << "Error fetching persistent statistics"
+					" for table "
+					<< table->name
+					<< " from " TABLE_STATS_NAME_PRINT " and "
+					INDEX_STATS_NAME_PRINT ": " << err
+					<< ". Using transient stats method instead.";
+			}
+
+			goto transient;
+		}
+	/* no "default:" in order to produce a compilation warning
+	about unhandled enumeration value */
+	}
+
+transient:
+	return dict_stats_update_transient(table);
+}
+
+/** Execute DELETE FROM mysql.innodb_table_stats
+@param database_name  database name
+@param table_name     table name
+@param trx            transaction (nullptr=start and commit a new one)
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_delete_from_table_stats(const char *database_name,
+                                           const char *table_name, trx_t *trx)
+{
+	pars_info_t*	pinfo;
+
+	ut_ad(dict_sys.locked());
+
+	pinfo = pars_info_create();
+
+	pars_info_add_str_literal(pinfo, "database_name", database_name);
+	pars_info_add_str_literal(pinfo, "table_name", table_name);
+
+	return dict_stats_exec_sql(
+		pinfo,
+		"PROCEDURE DELETE_FROM_TABLE_STATS () IS\n"
+		"BEGIN\n"
+		"DELETE FROM \"" TABLE_STATS_NAME "\" WHERE\n"
+		"database_name = :database_name AND\n"
+		"table_name = :table_name;\n"
+		"END;\n", trx);
+}
+
+/** Execute DELETE FROM mysql.innodb_index_stats
+@param database_name  database name
+@param table_name     table name
+@param trx            transaction
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_delete_from_index_stats(const char *database_name,
+                                           const char *table_name, trx_t *trx)
+{
+	pars_info_t*	pinfo;
+
+	ut_ad(dict_sys.locked());
+
+	pinfo = pars_info_create();
+
+	pars_info_add_str_literal(pinfo, "database_name", database_name);
+	pars_info_add_str_literal(pinfo, "table_name", table_name);
+
+	return dict_stats_exec_sql(
+		pinfo,
+		"PROCEDURE DELETE_FROM_INDEX_STATS () IS\n"
+		"BEGIN\n"
+		"DELETE FROM \"" INDEX_STATS_NAME "\" WHERE\n"
+		"database_name = :database_name AND\n"
+		"table_name = :table_name;\n"
+		"END;\n", trx);
+}
+
+/** Execute DELETE FROM mysql.innodb_index_stats
+@param database_name  database name
+@param table_name     table name
+@param index_name     name of the index
+@param trx            transaction
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_delete_from_index_stats(const char *database_name,
+                                           const char *table_name,
+                                           const char *index_name, trx_t *trx)
+{
+	pars_info_t*	pinfo;
+
+	ut_ad(dict_sys.locked());
+
+	pinfo = pars_info_create();
+
+	pars_info_add_str_literal(pinfo, "database_name", database_name);
+	pars_info_add_str_literal(pinfo, "table_name", table_name);
+	pars_info_add_str_literal(pinfo, "index_name", index_name);
+
+	return dict_stats_exec_sql(
+		pinfo,
+		"PROCEDURE DELETE_FROM_INDEX_STATS () IS\n"
+		"BEGIN\n"
+		"DELETE FROM \"" INDEX_STATS_NAME "\" WHERE\n"
+		"database_name = :database_name AND\n"
+		"table_name = :table_name AND\n"
+		"index_name = :index_name;\n"
+		"END;\n", trx);
+}
+
+/** Rename a table in InnoDB persistent stats storage.
+@param old_name  old table name
+@param new_name  new table name
+@param trx       transaction
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_rename_table(const char *old_name, const char *new_name,
+                                trx_t *trx)
+{
+  /* skip the statistics tables themselves */
+  if (!strcmp(old_name, TABLE_STATS_NAME) ||
+      !strcmp(old_name, INDEX_STATS_NAME) ||
+      !strcmp(new_name, TABLE_STATS_NAME) ||
+      !strcmp(new_name, INDEX_STATS_NAME))
+    return DB_SUCCESS;
+
+  char old_db[MAX_DB_UTF8_LEN];
+  char new_db[MAX_DB_UTF8_LEN];
+  char old_table[MAX_TABLE_UTF8_LEN];
+  char new_table[MAX_TABLE_UTF8_LEN];
+
+  dict_fs2utf8(old_name, old_db, sizeof old_db, old_table, sizeof old_table);
+  dict_fs2utf8(new_name, new_db, sizeof new_db, new_table, sizeof new_table);
+
+  if (dict_table_t::is_temporary_name(old_name) ||
+      dict_table_t::is_temporary_name(new_name))
+  {
+    if (dberr_t e= dict_stats_delete_from_table_stats(old_db, old_table, trx))
+      return e;
+    return dict_stats_delete_from_index_stats(old_db, old_table, trx);
+  }
+
+  pars_info_t *pinfo= pars_info_create();
+  pars_info_add_str_literal(pinfo, "old_db", old_db);
+  pars_info_add_str_literal(pinfo, "old_table", old_table);
+  pars_info_add_str_literal(pinfo, "new_db", new_db);
+  pars_info_add_str_literal(pinfo, "new_table", new_table);
+
+  static const char sql[]=
+    "PROCEDURE RENAME_TABLE_IN_STATS() IS\n"
+    "BEGIN\n"
+    "UPDATE \"" TABLE_STATS_NAME "\" SET\n"
+    "database_name=:new_db, table_name=:new_table\n"
+    "WHERE database_name=:old_db AND table_name=:old_table;\n"
+    "UPDATE \"" INDEX_STATS_NAME "\" SET\n"
+    "database_name=:new_db, table_name=:new_table\n"
+    "WHERE database_name=:old_db AND table_name=:old_table;\n"
+    "END;\n";
+
+  return dict_stats_exec_sql(pinfo, sql, trx);
+}
+
+/** Rename an index in InnoDB persistent statistics.
+@param db         database name
+@param table      table name
+@param old_name   old table name
+@param new_name   new table name
+@param trx        transaction
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_rename_index(const char *db, const char *table,
+                                const char *old_name, const char *new_name,
+                                trx_t *trx)
+{
+  if (!dict_stats_persistent_storage_check(true))
+    return DB_STATS_DO_NOT_EXIST;
+  pars_info_t *pinfo= pars_info_create();
+
+  pars_info_add_str_literal(pinfo, "db", db);
+  pars_info_add_str_literal(pinfo, "table", table);
+  pars_info_add_str_literal(pinfo, "old", old_name);
+  pars_info_add_str_literal(pinfo, "new", new_name);
+
+  static const char sql[]=
+    "PROCEDURE RENAME_INDEX_IN_STATS() IS\n"
+    "BEGIN\n"
+    "UPDATE \"" INDEX_STATS_NAME "\" SET index_name=:new\n"
+    "WHERE database_name=:db AND table_name=:table AND index_name=:old;\n"
+    "END;\n";
+
+  return dict_stats_exec_sql(pinfo, sql, trx);
+}
+
+/** Delete all persistent statistics for a database.
+@param db    database name
+@param trx   transaction
+@return DB_SUCCESS or error code */
+dberr_t dict_stats_delete(const char *db, trx_t *trx)
+{
+  static const char sql[] =
+    "PROCEDURE DROP_DATABASE_STATS () IS\n"
+    "BEGIN\n"
+    "DELETE FROM \"" TABLE_STATS_NAME "\" WHERE database_name=:db;\n"
+    "DELETE FROM \"" INDEX_STATS_NAME "\" WHERE database_name=:db;\n"
+    "END;\n";
+
+  pars_info_t *pinfo= pars_info_create();
+  pars_info_add_str_literal(pinfo, "db", db);
+  return dict_stats_exec_sql(pinfo, sql, trx);
+}
+
+/* tests @{ */
+#ifdef UNIV_ENABLE_UNIT_TEST_DICT_STATS
+/* save/fetch aux macros @{ */
+#define TEST_DATABASE_NAME		"foobardb"
+#define TEST_TABLE_NAME			"test_dict_stats"
+
+#define TEST_N_ROWS			111
+#define TEST_CLUSTERED_INDEX_SIZE	222
+#define TEST_SUM_OF_OTHER_INDEX_SIZES	333
+
+#define TEST_IDX1_NAME			"tidx1"
+#define TEST_IDX1_COL1_NAME		"tidx1_col1"
+#define TEST_IDX1_INDEX_SIZE		123
+#define TEST_IDX1_N_LEAF_PAGES		234
+#define TEST_IDX1_N_DIFF1		50
+#define TEST_IDX1_N_DIFF1_SAMPLE_SIZE	500
+
+#define TEST_IDX2_NAME			"tidx2"
+#define TEST_IDX2_COL1_NAME		"tidx2_col1"
+#define TEST_IDX2_COL2_NAME		"tidx2_col2"
+#define TEST_IDX2_COL3_NAME		"tidx2_col3"
+#define TEST_IDX2_COL4_NAME		"tidx2_col4"
+#define TEST_IDX2_INDEX_SIZE		321
+#define TEST_IDX2_N_LEAF_PAGES		432
+#define TEST_IDX2_N_DIFF1		60
+#define TEST_IDX2_N_DIFF1_SAMPLE_SIZE	600
+#define TEST_IDX2_N_DIFF2		61
+#define TEST_IDX2_N_DIFF2_SAMPLE_SIZE	610
+#define TEST_IDX2_N_DIFF3		62
+#define TEST_IDX2_N_DIFF3_SAMPLE_SIZE	620
+#define TEST_IDX2_N_DIFF4		63
+#define TEST_IDX2_N_DIFF4_SAMPLE_SIZE	630
+/* @} */
+
+/* test_dict_stats_save() @{ */
+void
+test_dict_stats_save()
+{
+	dict_table_t	table;
+	dict_index_t	index1;
+	dict_field_t	index1_fields[1];
+	ib_uint64_t	index1_stat_n_diff_key_vals[1];
+	ib_uint64_t	index1_stat_n_sample_sizes[1];
+	dict_index_t	index2;
+	dict_field_t	index2_fields[4];
+	ib_uint64_t	index2_stat_n_diff_key_vals[4];
+	ib_uint64_t	index2_stat_n_sample_sizes[4];
+	dberr_t		ret;
+
+	/* craft a dummy dict_table_t */
+	table.name.m_name = (char*) (TEST_DATABASE_NAME "/" TEST_TABLE_NAME);
+	table.stat_n_rows = TEST_N_ROWS;
+	table.stat_clustered_index_size = TEST_CLUSTERED_INDEX_SIZE;
+	table.stat_sum_of_other_index_sizes = TEST_SUM_OF_OTHER_INDEX_SIZES;
+	UT_LIST_INIT(table.indexes, &dict_index_t::indexes);
+#ifdef BTR_CUR_HASH_ADAPT
+	UT_LIST_INIT(table.freed_indexes, &dict_index_t::indexes);
+#endif /* BTR_CUR_HASH_ADAPT */
+	UT_LIST_ADD_LAST(table.indexes, &index1);
+	UT_LIST_ADD_LAST(table.indexes, &index2);
+	ut_d(table.magic_n = DICT_TABLE_MAGIC_N);
+	ut_d(index1.magic_n = DICT_INDEX_MAGIC_N);
+
+	index1.name = TEST_IDX1_NAME;
+	index1.table = &table;
+	index1.cached = 1;
+	index1.n_uniq = 1;
+	index1.fields = index1_fields;
+	index1.stat_n_diff_key_vals = index1_stat_n_diff_key_vals;
+	index1.stat_n_sample_sizes = index1_stat_n_sample_sizes;
+	index1.stat_index_size = TEST_IDX1_INDEX_SIZE;
+	index1.stat_n_leaf_pages = TEST_IDX1_N_LEAF_PAGES;
+	index1_fields[0].name = TEST_IDX1_COL1_NAME;
+	index1_stat_n_diff_key_vals[0] = TEST_IDX1_N_DIFF1;
+	index1_stat_n_sample_sizes[0] = TEST_IDX1_N_DIFF1_SAMPLE_SIZE;
+
+	ut_d(index2.magic_n = DICT_INDEX_MAGIC_N);
+	index2.name = TEST_IDX2_NAME;
+	index2.table = &table;
+	index2.cached = 1;
+	index2.n_uniq = 4;
+	index2.fields = index2_fields;
+	index2.stat_n_diff_key_vals = index2_stat_n_diff_key_vals;
+	index2.stat_n_sample_sizes = index2_stat_n_sample_sizes;
+	index2.stat_index_size = TEST_IDX2_INDEX_SIZE;
+	index2.stat_n_leaf_pages = TEST_IDX2_N_LEAF_PAGES;
+	index2_fields[0].name = TEST_IDX2_COL1_NAME;
+	index2_fields[1].name = TEST_IDX2_COL2_NAME;
+	index2_fields[2].name = TEST_IDX2_COL3_NAME;
+	index2_fields[3].name = TEST_IDX2_COL4_NAME;
+	index2_stat_n_diff_key_vals[0] = TEST_IDX2_N_DIFF1;
+	index2_stat_n_diff_key_vals[1] = TEST_IDX2_N_DIFF2;
+	index2_stat_n_diff_key_vals[2] = TEST_IDX2_N_DIFF3;
+	index2_stat_n_diff_key_vals[3] = TEST_IDX2_N_DIFF4;
+	index2_stat_n_sample_sizes[0] = TEST_IDX2_N_DIFF1_SAMPLE_SIZE;
+	index2_stat_n_sample_sizes[1] = TEST_IDX2_N_DIFF2_SAMPLE_SIZE;
+	index2_stat_n_sample_sizes[2] = TEST_IDX2_N_DIFF3_SAMPLE_SIZE;
+	index2_stat_n_sample_sizes[3] = TEST_IDX2_N_DIFF4_SAMPLE_SIZE;
+
+	ret = dict_stats_save(&table, NULL);
+
+	ut_a(ret == DB_SUCCESS);
+
+	printf("\nOK: stats saved successfully, now go ahead and read"
+	       " what's inside %s and %s:\n\n",
+	       TABLE_STATS_NAME_PRINT,
+	       INDEX_STATS_NAME_PRINT);
+
+	printf("SELECT COUNT(*) = 1 AS table_stats_saved_successfully\n"
+	       "FROM %s\n"
+	       "WHERE\n"
+	       "database_name = '%s' AND\n"
+	       "table_name = '%s' AND\n"
+	       "n_rows = %d AND\n"
+	       "clustered_index_size = %d AND\n"
+	       "sum_of_other_index_sizes = %d;\n"
+	       "\n",
+	       TABLE_STATS_NAME_PRINT,
+	       TEST_DATABASE_NAME,
+	       TEST_TABLE_NAME,
+	       TEST_N_ROWS,
+	       TEST_CLUSTERED_INDEX_SIZE,
+	       TEST_SUM_OF_OTHER_INDEX_SIZES);
+
+	printf("SELECT COUNT(*) = 3 AS tidx1_stats_saved_successfully\n"
+	       "FROM %s\n"
+	       "WHERE\n"
+	       "database_name = '%s' AND\n"
+	       "table_name = '%s' AND\n"
+	       "index_name = '%s' AND\n"
+	       "(\n"
+	       " (stat_name = 'size' AND stat_value = %d AND"
+	       "  sample_size IS NULL) OR\n"
+	       " (stat_name = 'n_leaf_pages' AND stat_value = %d AND"
+	       "  sample_size IS NULL) OR\n"
+	       " (stat_name = 'n_diff_pfx01' AND stat_value = %d AND"
+	       "  sample_size = '%d' AND stat_description = '%s')\n"
+	       ");\n"
+	       "\n",
+	       INDEX_STATS_NAME_PRINT,
+	       TEST_DATABASE_NAME,
+	       TEST_TABLE_NAME,
+	       TEST_IDX1_NAME,
+	       TEST_IDX1_INDEX_SIZE,
+	       TEST_IDX1_N_LEAF_PAGES,
+	       TEST_IDX1_N_DIFF1,
+	       TEST_IDX1_N_DIFF1_SAMPLE_SIZE,
+	       TEST_IDX1_COL1_NAME);
+
+	printf("SELECT COUNT(*) = 6 AS tidx2_stats_saved_successfully\n"
+	       "FROM %s\n"
+	       "WHERE\n"
+	       "database_name = '%s' AND\n"
+	       "table_name = '%s' AND\n"
+	       "index_name = '%s' AND\n"
+	       "(\n"
+	       " (stat_name = 'size' AND stat_value = %d AND"
+	       "  sample_size IS NULL) OR\n"
+	       " (stat_name = 'n_leaf_pages' AND stat_value = %d AND"
+	       "  sample_size IS NULL) OR\n"
+	       " (stat_name = 'n_diff_pfx01' AND stat_value = %d AND"
+	       "  sample_size = '%d' AND stat_description = '%s') OR\n"
+	       " (stat_name = 'n_diff_pfx02' AND stat_value = %d AND"
+	       "  sample_size = '%d' AND stat_description = '%s,%s') OR\n"
+	       " (stat_name = 'n_diff_pfx03' AND stat_value = %d AND"
+	       "  sample_size = '%d' AND stat_description = '%s,%s,%s') OR\n"
+	       " (stat_name = 'n_diff_pfx04' AND stat_value = %d AND"
+	       "  sample_size = '%d' AND stat_description = '%s,%s,%s,%s')\n"
+	       ");\n"
+	       "\n",
+	       INDEX_STATS_NAME_PRINT,
+	       TEST_DATABASE_NAME,
+	       TEST_TABLE_NAME,
+	       TEST_IDX2_NAME,
+	       TEST_IDX2_INDEX_SIZE,
+	       TEST_IDX2_N_LEAF_PAGES,
+	       TEST_IDX2_N_DIFF1,
+	       TEST_IDX2_N_DIFF1_SAMPLE_SIZE, TEST_IDX2_COL1_NAME,
+	       TEST_IDX2_N_DIFF2,
+	       TEST_IDX2_N_DIFF2_SAMPLE_SIZE,
+	       TEST_IDX2_COL1_NAME, TEST_IDX2_COL2_NAME,
+	       TEST_IDX2_N_DIFF3,
+	       TEST_IDX2_N_DIFF3_SAMPLE_SIZE,
+	       TEST_IDX2_COL1_NAME, TEST_IDX2_COL2_NAME, TEST_IDX2_COL3_NAME,
+	       TEST_IDX2_N_DIFF4,
+	       TEST_IDX2_N_DIFF4_SAMPLE_SIZE,
+	       TEST_IDX2_COL1_NAME, TEST_IDX2_COL2_NAME, TEST_IDX2_COL3_NAME,
+	       TEST_IDX2_COL4_NAME);
+}
+/* @} */
+
+/* test_dict_stats_fetch_from_ps() @{ */
+void
+test_dict_stats_fetch_from_ps()
+{
+	dict_table_t	table;
+	dict_index_t	index1;
+	ib_uint64_t	index1_stat_n_diff_key_vals[1];
+	ib_uint64_t	index1_stat_n_sample_sizes[1];
+	dict_index_t	index2;
+	ib_uint64_t	index2_stat_n_diff_key_vals[4];
+	ib_uint64_t	index2_stat_n_sample_sizes[4];
+	dberr_t		ret;
+
+	/* craft a dummy dict_table_t */
+	table.name.m_name = (char*) (TEST_DATABASE_NAME "/" TEST_TABLE_NAME);
+	UT_LIST_INIT(table.indexes, &dict_index_t::indexes);
+#ifdef BTR_CUR_HASH_ADAPT
+	UT_LIST_INIT(table.freed_indexes, &dict_index_t::indexes);
+#endif /* BTR_CUR_HASH_ADAPT */
+	UT_LIST_ADD_LAST(table.indexes, &index1);
+	UT_LIST_ADD_LAST(table.indexes, &index2);
+	ut_d(table.magic_n = DICT_TABLE_MAGIC_N);
+
+	index1.name = TEST_IDX1_NAME;
+	ut_d(index1.magic_n = DICT_INDEX_MAGIC_N);
+	index1.cached = 1;
+	index1.n_uniq = 1;
+	index1.stat_n_diff_key_vals = index1_stat_n_diff_key_vals;
+	index1.stat_n_sample_sizes = index1_stat_n_sample_sizes;
+
+	index2.name = TEST_IDX2_NAME;
+	ut_d(index2.magic_n = DICT_INDEX_MAGIC_N);
+	index2.cached = 1;
+	index2.n_uniq = 4;
+	index2.stat_n_diff_key_vals = index2_stat_n_diff_key_vals;
+	index2.stat_n_sample_sizes = index2_stat_n_sample_sizes;
+
+	ret = dict_stats_fetch_from_ps(&table);
+
+	ut_a(ret == DB_SUCCESS);
+
+	ut_a(table.stat_n_rows == TEST_N_ROWS);
+	ut_a(table.stat_clustered_index_size == TEST_CLUSTERED_INDEX_SIZE);
+	ut_a(table.stat_sum_of_other_index_sizes
+	     == TEST_SUM_OF_OTHER_INDEX_SIZES);
+
+	ut_a(index1.stat_index_size == TEST_IDX1_INDEX_SIZE);
+	ut_a(index1.stat_n_leaf_pages == TEST_IDX1_N_LEAF_PAGES);
+	ut_a(index1_stat_n_diff_key_vals[0] == TEST_IDX1_N_DIFF1);
+	ut_a(index1_stat_n_sample_sizes[0] == TEST_IDX1_N_DIFF1_SAMPLE_SIZE);
+
+	ut_a(index2.stat_index_size == TEST_IDX2_INDEX_SIZE);
+	ut_a(index2.stat_n_leaf_pages == TEST_IDX2_N_LEAF_PAGES);
+	ut_a(index2_stat_n_diff_key_vals[0] == TEST_IDX2_N_DIFF1);
+	ut_a(index2_stat_n_sample_sizes[0] == TEST_IDX2_N_DIFF1_SAMPLE_SIZE);
+	ut_a(index2_stat_n_diff_key_vals[1] == TEST_IDX2_N_DIFF2);
+	ut_a(index2_stat_n_sample_sizes[1] == TEST_IDX2_N_DIFF2_SAMPLE_SIZE);
+	ut_a(index2_stat_n_diff_key_vals[2] == TEST_IDX2_N_DIFF3);
+	ut_a(index2_stat_n_sample_sizes[2] == TEST_IDX2_N_DIFF3_SAMPLE_SIZE);
+	ut_a(index2_stat_n_diff_key_vals[3] == TEST_IDX2_N_DIFF4);
+	ut_a(index2_stat_n_sample_sizes[3] == TEST_IDX2_N_DIFF4_SAMPLE_SIZE);
+
+	printf("OK: fetch successful\n");
+}
+/* @} */
+
+/* test_dict_stats_all() @{ */
+void
+test_dict_stats_all()
+{
+	test_dict_table_schema_check();
+
+	test_dict_stats_save();
+
+	test_dict_stats_fetch_from_ps();
+}
+/* @} */
+
+#endif /* UNIV_ENABLE_UNIT_TEST_DICT_STATS */
+/* @} */
diff --git a/storage/innobase/dict/dict0stats_bg.cc b/storage/innobase/dict/dict0stats_bg.cc
new file mode 100644
index 00000000..a66aac22
--- /dev/null
+++ b/storage/innobase/dict/dict0stats_bg.cc
@@ -0,0 +1,424 @@
+/*****************************************************************************
+
+Copyright (c) 2012, 2017, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file dict/dict0stats_bg.cc
+Code used for background table and index stats gathering.
+
+Created Apr 25, 2012 Vasil Dimov
+*******************************************************/
+
+#include "dict0dict.h"
+#include "dict0stats.h"
+#include "dict0stats_bg.h"
+#include "dict0defrag_bg.h"
+#include "row0mysql.h"
+#include "srv0start.h"
+#include "fil0fil.h"
+#include "mysqld.h"
+#ifdef WITH_WSREP
+# include "trx0trx.h"
+# include "mysql/service_wsrep.h"
+# include "wsrep.h"
+# include "log.h"
+#endif
+
+#include <vector>
+
+/** Minimum time interval between stats recalc for a given table */
+#define MIN_RECALC_INTERVAL	10 /* seconds */
+static void dict_stats_schedule(int ms);
+
+/** Protects recalc_pool */
+static mysql_mutex_t recalc_pool_mutex;
+
+/** for signaling recalc::state */
+static pthread_cond_t recalc_pool_cond;
+
+/** Work item of the recalc_pool; protected by recalc_pool_mutex */
+struct recalc
+{
+  /** identifies a table with persistent statistics */
+  table_id_t id;
+  /** state of the entry */
+  enum { IDLE, IN_PROGRESS, IN_PROGRESS_DELETING, DELETING} state;
+};
+
+/** The multitude of tables whose stats are to be automatically recalculated */
+typedef std::vector<recalc, ut_allocator<recalc>> recalc_pool_t;
+
+/** Pool where we store information on which tables are to be processed
+by background statistics gathering. */
+static recalc_pool_t		recalc_pool;
+/** Whether the global data structures have been initialized */
+static bool			stats_initialised;
+
+/*****************************************************************//**
+Free the resources occupied by the recalc pool, called once during
+thread de-initialization. */
+static void dict_stats_recalc_pool_deinit()
+{
+	ut_ad(!srv_read_only_mode);
+
+	recalc_pool.clear();
+	defrag_pool.clear();
+        /*
+          recalc_pool may still have its buffer allocated. It will free it when
+          its destructor is called.
+          The problem is, memory leak detector is run before the recalc_pool's
+          destructor is invoked, and will report recalc_pool's buffer as leaked
+          memory.  To avoid that, we force recalc_pool to surrender its buffer
+          to empty_pool object, which will free it when leaving this function:
+        */
+	recalc_pool_t recalc_empty_pool;
+	defrag_pool_t defrag_empty_pool;
+	recalc_pool.swap(recalc_empty_pool);
+	defrag_pool.swap(defrag_empty_pool);
+}
+
+/*****************************************************************//**
+Add a table to the recalc pool, which is processed by the
+background stats gathering thread. Only the table id is added to the
+list, so the table can be closed after being enqueued and it will be
+opened when needed. If the table does not exist later (has been DROPped),
+then it will be removed from the pool and skipped. */
+static void dict_stats_recalc_pool_add(table_id_t id)
+{
+  ut_ad(!srv_read_only_mode);
+  ut_ad(id);
+  bool schedule = false;
+  mysql_mutex_lock(&recalc_pool_mutex);
+
+  const auto begin= recalc_pool.begin(), end= recalc_pool.end();
+  if (end == std::find_if(begin, end, [&](const recalc &r){return r.id == id;}))
+  {
+    recalc_pool.emplace_back(recalc{id, recalc::IDLE});
+    schedule = true;
+  }
+
+  mysql_mutex_unlock(&recalc_pool_mutex);
+  if (schedule)
+    dict_stats_schedule_now();
+}
+
+#ifdef WITH_WSREP
+/** Update the table modification counter and if necessary,
+schedule new estimates for table and index statistics to be calculated.
+@param[in,out]	table	persistent or temporary table
+@param[in]	thd	current session */
+void dict_stats_update_if_needed(dict_table_t *table, const trx_t &trx)
+#else
+/** Update the table modification counter and if necessary,
+schedule new estimates for table and index statistics to be calculated.
+@param[in,out]	table	persistent or temporary table */
+void dict_stats_update_if_needed_func(dict_table_t *table)
+#endif
+{
+	if (UNIV_UNLIKELY(!table->stat_initialized)) {
+		/* The table may have been evicted from dict_sys
+		and reloaded internally by InnoDB for FOREIGN KEY
+		processing, but not reloaded by the SQL layer.
+
+		We can (re)compute the transient statistics when the
+		table is actually loaded by the SQL layer.
+
+		Note: If InnoDB persistent statistics are enabled,
+		we will skip the updates. We must do this, because
+		dict_table_get_n_rows() below assumes that the
+		statistics have been initialized. The DBA may have
+		to execute ANALYZE TABLE. */
+		return;
+	}
+
+	ulonglong	counter = table->stat_modified_counter++;
+	ulonglong	n_rows = dict_table_get_n_rows(table);
+
+	if (dict_stats_is_persistent_enabled(table)) {
+		if (table->name.is_temporary()) {
+			return;
+		}
+		if (counter > n_rows / 10 /* 10% */
+		    && dict_stats_auto_recalc_is_enabled(table)) {
+
+#ifdef WITH_WSREP
+			/* Do not add table to background
+			statistic calculation if this thread is not a
+			applier (as all DDL, which is replicated (i.e
+			is binlogged in master node), will be executed
+			with high priority (a.k.a BF) in slave nodes)
+			and is BF. This could again lead BF lock
+			waits in applier node but it is better than
+			no persistent index/table statistics at
+			applier nodes. TODO: allow BF threads
+			wait for these InnoDB internal SQL-parser
+			generated row locks and allow BF thread
+			lock waits to be enqueued at head of waiting
+			queue. */
+			if (trx.is_wsrep()
+			    && !wsrep_thd_is_applying(trx.mysql_thd)
+			    && wsrep_thd_is_BF(trx.mysql_thd, 0)) {
+				WSREP_DEBUG("Avoiding background statistics"
+					    " calculation for table %s.",
+					table->name.m_name);
+				return;
+			}
+#endif /* WITH_WSREP */
+
+			dict_stats_recalc_pool_add(table->id);
+			table->stat_modified_counter = 0;
+		}
+		return;
+	}
+
+	/* Calculate new statistics if 1 / 16 of table has been modified
+	since the last time a statistics batch was run.
+	We calculate statistics at most every 16th round, since we may have
+	a counter table which is very small and updated very often. */
+	ulonglong threshold = 16 + n_rows / 16; /* 6.25% */
+
+	if (srv_stats_modified_counter) {
+		threshold = std::min(srv_stats_modified_counter, threshold);
+	}
+
+	if (counter > threshold) {
+		/* this will reset table->stat_modified_counter to 0 */
+		dict_stats_update(table, DICT_STATS_RECALC_TRANSIENT);
+	}
+}
+
+/** Delete a table from the auto recalc pool, and ensure that
+no statistics are being updated on it. */
+void dict_stats_recalc_pool_del(table_id_t id, bool have_mdl_exclusive)
+{
+  ut_ad(!srv_read_only_mode);
+  ut_ad(id);
+
+  mysql_mutex_lock(&recalc_pool_mutex);
+
+  auto end= recalc_pool.end();
+  auto i= std::find_if(recalc_pool.begin(), end,
+                       [&](const recalc &r){return r.id == id;});
+  if (i != end)
+  {
+    switch (i->state) {
+    case recalc::IN_PROGRESS:
+      if (!have_mdl_exclusive)
+      {
+        i->state= recalc::IN_PROGRESS_DELETING;
+        do
+        {
+          my_cond_wait(&recalc_pool_cond, &recalc_pool_mutex.m_mutex);
+          end= recalc_pool.end();
+          i= std::find_if(recalc_pool.begin(), end,
+                          [&](const recalc &r){return r.id == id;});
+          if (i == end)
+            goto done;
+        }
+        while (i->state == recalc::IN_PROGRESS_DELETING);
+      }
+      /* fall through */
+    case recalc::IDLE:
+      recalc_pool.erase(i);
+      break;
+    case recalc::IN_PROGRESS_DELETING:
+    case recalc::DELETING:
+      /* another thread will delete the entry in dict_stats_recalc_pool_del() */
+      break;
+    }
+  }
+
+done:
+  mysql_mutex_unlock(&recalc_pool_mutex);
+}
+
+/*****************************************************************//**
+Initialize global variables needed for the operation of dict_stats_thread()
+Must be called before dict_stats_thread() is started. */
+void dict_stats_init()
+{
+  ut_ad(!srv_read_only_mode);
+  mysql_mutex_init(recalc_pool_mutex_key, &recalc_pool_mutex, nullptr);
+  pthread_cond_init(&recalc_pool_cond, nullptr);
+  dict_defrag_pool_init();
+  stats_initialised= true;
+}
+
+/*****************************************************************//**
+Free resources allocated by dict_stats_init(), must be called
+after dict_stats task has exited. */
+void dict_stats_deinit()
+{
+	if (!stats_initialised) {
+		return;
+	}
+
+	ut_ad(!srv_read_only_mode);
+	stats_initialised = false;
+
+	dict_stats_recalc_pool_deinit();
+	dict_defrag_pool_deinit();
+
+	mysql_mutex_destroy(&recalc_pool_mutex);
+	pthread_cond_destroy(&recalc_pool_cond);
+}
+
+/**
+Get the first table that has been added for auto recalc and eventually
+update its stats.
+@return whether the first entry can be processed immediately */
+static bool dict_stats_process_entry_from_recalc_pool(THD *thd)
+{
+  ut_ad(!srv_read_only_mode);
+  table_id_t table_id;
+  mysql_mutex_lock(&recalc_pool_mutex);
+next_table_id_with_mutex:
+  for (auto &r : recalc_pool)
+  {
+    if ((table_id= r.id) && r.state == recalc::IDLE)
+    {
+      r.state= recalc::IN_PROGRESS;
+      mysql_mutex_unlock(&recalc_pool_mutex);
+      goto process;
+    }
+  }
+  mysql_mutex_unlock(&recalc_pool_mutex);
+  return false;
+
+process:
+  MDL_ticket *mdl= nullptr;
+  dict_table_t *table= dict_table_open_on_id(table_id, false,
+                                             DICT_TABLE_OP_NORMAL, thd, &mdl);
+  if (!table)
+  {
+invalid_table_id:
+    mysql_mutex_lock(&recalc_pool_mutex);
+    auto i= std::find_if(recalc_pool.begin(), recalc_pool.end(),
+                         [&](const recalc &r){return r.id == table_id;});
+    if (i == recalc_pool.end());
+    else if (UNIV_LIKELY(i->state == recalc::IN_PROGRESS))
+      recalc_pool.erase(i);
+    else
+    {
+      ut_ad(i->state == recalc::IN_PROGRESS_DELETING);
+      i->state= recalc::DELETING;
+      pthread_cond_broadcast(&recalc_pool_cond);
+    }
+    goto next_table_id_with_mutex;
+  }
+
+  ut_ad(!table->is_temporary());
+
+  if (!mdl || !table->is_accessible())
+  {
+    dict_table_close(table, false, thd, mdl);
+    goto invalid_table_id;
+  }
+
+  /* time() could be expensive, the current function
+  is called once every time a table has been changed more than 10% and
+  on a system with lots of small tables, this could become hot. If we
+  find out that this is a problem, then the check below could eventually
+  be replaced with something else, though a time interval is the natural
+  approach. */
+  const bool update_now=
+    difftime(time(nullptr), table->stats_last_recalc) >= MIN_RECALC_INTERVAL;
+
+  const dberr_t err= update_now
+    ? dict_stats_update(table, DICT_STATS_RECALC_PERSISTENT)
+    : DB_SUCCESS_LOCKED_REC;
+
+  dict_table_close(table, false, thd, mdl);
+
+  mysql_mutex_lock(&recalc_pool_mutex);
+  auto i= std::find_if(recalc_pool.begin(), recalc_pool.end(),
+                       [&](const recalc &r){return r.id == table_id;});
+  if (i == recalc_pool.end())
+    goto done;
+  else if (i->state == recalc::IN_PROGRESS_DELETING)
+  {
+    i->state= recalc::DELETING;
+    pthread_cond_broadcast(&recalc_pool_cond);
+done:
+    mysql_mutex_unlock(&recalc_pool_mutex);
+  }
+  else
+  {
+    ut_ad(i->state == recalc::IN_PROGRESS);
+    recalc_pool.erase(i);
+    const bool reschedule= !update_now && recalc_pool.empty();
+    if (err == DB_SUCCESS_LOCKED_REC)
+      recalc_pool.emplace_back(recalc{table_id, recalc::IDLE});
+    mysql_mutex_unlock(&recalc_pool_mutex);
+    if (reschedule)
+      dict_stats_schedule(MIN_RECALC_INTERVAL * 1000);
+  }
+
+  return update_now;
+}
+
+static tpool::timer* dict_stats_timer;
+static std::mutex dict_stats_mutex;
+
+static void dict_stats_func(void*)
+{
+  THD *thd= innobase_create_background_thd("InnoDB statistics");
+  set_current_thd(thd);
+  while (dict_stats_process_entry_from_recalc_pool(thd)) {}
+  dict_defrag_process_entries_from_defrag_pool(thd);
+  set_current_thd(nullptr);
+  destroy_background_thd(thd);
+}
+
+
+void dict_stats_start()
+{
+  std::lock_guard<std::mutex> lk(dict_stats_mutex);
+  if (!dict_stats_timer)
+    dict_stats_timer= srv_thread_pool->create_timer(dict_stats_func);
+}
+
+
+static void dict_stats_schedule(int ms)
+{
+  std::unique_lock<std::mutex> lk(dict_stats_mutex, std::defer_lock);
+  /*
+    Use try_lock() to avoid deadlock in dict_stats_shutdown(), which
+    uses dict_stats_mutex too. If there is simultaneous timer reschedule,
+    the first one will win, which is fine.
+  */
+  if (!lk.try_lock())
+  {
+    return;
+  }
+  if (dict_stats_timer)
+    dict_stats_timer->set_time(ms,0);
+}
+
+void dict_stats_schedule_now()
+{
+  dict_stats_schedule(0);
+}
+
+/** Shut down the dict_stats_thread. */
+void dict_stats_shutdown()
+{
+  std::lock_guard<std::mutex> lk(dict_stats_mutex);
+  delete dict_stats_timer;
+  dict_stats_timer= 0;
+}
diff --git a/storage/innobase/dict/drop.cc b/storage/innobase/dict/drop.cc
new file mode 100644
index 00000000..dce71974
--- /dev/null
+++ b/storage/innobase/dict/drop.cc
@@ -0,0 +1,297 @@
+/*****************************************************************************
+
+Copyright (c) 2021, 2022, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+/**
+@file dict/drop.cc
+Data Dictionary Language operations that delete .ibd files */
+
+/* We implement atomic data dictionary operations as follows.
+
+1. A data dictionary transaction is started.
+2. We acquire exclusive lock on all the tables that are to be dropped
+during the execution of the transaction.
+3. We lock the data dictionary cache.
+4. All metadata tables will be updated within the single DDL transaction,
+including deleting or renaming InnoDB persistent statistics.
+4b. If any lock wait would occur while we are holding the dict_sys latches,
+we will instantly report a timeout error and roll back the transaction.
+5. The transaction metadata is marked as committed.
+6. If any files were deleted, we will durably write FILE_DELETE
+to the redo log and start deleting the files.
+6b. Also purge after a commit may perform file deletion. This is also the
+recovery mechanism if the server was killed between step 5 and 6.
+7. We unlock the data dictionary cache.
+8. The file handles of the unlinked files will be closed. This will actually
+reclaim the space in the file system (delete-on-close semantics).
+
+Notes:
+
+(a) Purge will be locked out by MDL. For internal tables related to
+FULLTEXT INDEX, purge will not acquire MDL on the user table name,
+and therefore, when we are dropping any FTS_ tables, we must suspend
+and resume purge to prevent a race condition.
+
+(b) If a transaction needs to both drop and create a table by some
+name, it must rename the table in between. This is used by
+ha_innobase::truncate() and fts_drop_common_tables().
+
+(c) No data is ever destroyed before the transaction is committed,
+so we can trivially roll back the transaction at any time.
+Lock waits during a DDL operation are no longer a fatal error
+that would cause the InnoDB to hang or to intentionally crash.
+(Only ALTER TABLE...DISCARD TABLESPACE may discard data before commit.)
+
+(d) The only changes to the data dictionary cache that are performed
+before transaction commit and must be rolled back explicitly are as follows:
+(d1) fts_optimize_add_table() to undo fts_optimize_remove_table()
+*/
+
+#include "trx0purge.h"
+#include "dict0dict.h"
+#include "dict0stats.h"
+#include "dict0stats_bg.h"
+
+#include "dict0defrag_bg.h"
+#include "btr0defragment.h"
+#include "ibuf0ibuf.h"
+#include "lock0lock.h"
+
+#include "que0que.h"
+#include "pars0pars.h"
+
+/** Try to drop the foreign key constraints for a persistent table.
+@param name        name of persistent table
+@return error code */
+dberr_t trx_t::drop_table_foreign(const table_name_t &name)
+{
+  ut_ad(dict_sys.locked());
+  ut_ad(state == TRX_STATE_ACTIVE);
+  ut_ad(dict_operation);
+  ut_ad(dict_operation_lock_mode);
+
+  if (!dict_sys.sys_foreign || dict_sys.sys_foreign->corrupted)
+    return DB_SUCCESS;
+
+  if (!dict_sys.sys_foreign_cols || dict_sys.sys_foreign_cols->corrupted)
+    return DB_SUCCESS;
+
+  pars_info_t *info= pars_info_create();
+  pars_info_add_str_literal(info, "name", name.m_name);
+  return que_eval_sql(info,
+                      "PROCEDURE DROP_FOREIGN() IS\n"
+                      "fid CHAR;\n"
+
+                      "DECLARE CURSOR fk IS\n"
+                      "SELECT ID FROM SYS_FOREIGN\n"
+                      "WHERE FOR_NAME=:name\n"
+                      "AND TO_BINARY(FOR_NAME)=TO_BINARY(:name)\n"
+                      "FOR UPDATE;\n"
+
+                      "BEGIN\n"
+                      "OPEN fk;\n"
+                      "WHILE 1=1 LOOP\n"
+                      "  FETCH fk INTO fid;\n"
+                      "  IF (SQL % NOTFOUND)THEN RETURN;END IF;\n"
+                      "  DELETE FROM SYS_FOREIGN_COLS"
+                      " WHERE ID=fid;\n"
+                      "  DELETE FROM SYS_FOREIGN WHERE ID=fid;\n"
+                      "END LOOP;\n"
+                      "CLOSE fk;\n"
+                      "END;\n", this);
+}
+
+/** Try to drop the statistics for a persistent table.
+@param name        name of persistent table
+@return error code */
+dberr_t trx_t::drop_table_statistics(const table_name_t &name)
+{
+  ut_ad(dict_sys.locked());
+  ut_ad(dict_operation_lock_mode);
+
+  if (strstr(name.m_name, "/" TEMP_FILE_PREFIX_INNODB) ||
+      !strcmp(name.m_name, TABLE_STATS_NAME) ||
+      !strcmp(name.m_name, INDEX_STATS_NAME))
+    return DB_SUCCESS;
+
+  char db[MAX_DB_UTF8_LEN], table[MAX_TABLE_UTF8_LEN];
+  dict_fs2utf8(name.m_name, db, sizeof db, table, sizeof table);
+
+  dberr_t err= dict_stats_delete_from_table_stats(db, table, this);
+  if (err == DB_SUCCESS || err == DB_STATS_DO_NOT_EXIST)
+  {
+    err= dict_stats_delete_from_index_stats(db, table, this);
+    if (err == DB_STATS_DO_NOT_EXIST)
+      err= DB_SUCCESS;
+  }
+  return err;
+}
+
+/** Try to drop a persistent table.
+@param table       persistent table
+@param fk          whether to drop FOREIGN KEY metadata
+@return error code */
+dberr_t trx_t::drop_table(const dict_table_t &table)
+{
+  ut_ad(dict_sys.locked());
+  ut_ad(state == TRX_STATE_ACTIVE);
+  ut_ad(dict_operation);
+  ut_ad(dict_operation_lock_mode);
+  ut_ad(!table.is_temporary());
+  /* The table must be exclusively locked by this transaction. */
+  ut_ad(table.get_ref_count() <= 1);
+  ut_ad(table.n_lock_x_or_s == 1);
+  ut_ad(UT_LIST_GET_LEN(table.locks) >= 1);
+#ifdef UNIV_DEBUG
+  bool found_x= false;
+  for (lock_t *lock= UT_LIST_GET_FIRST(table.locks); lock;
+       lock= UT_LIST_GET_NEXT(un_member.tab_lock.locks, lock))
+  {
+    ut_ad(lock->trx == this);
+    switch (lock->type_mode) {
+    case LOCK_TABLE | LOCK_X:
+      found_x= true;
+      break;
+    case LOCK_TABLE | LOCK_IX:
+    case LOCK_TABLE | LOCK_AUTO_INC:
+      break;
+    default:
+      ut_ad("unexpected lock type" == 0);
+    }
+  }
+  ut_ad(found_x);
+#endif
+
+  if (dict_sys.sys_virtual && !dict_sys.sys_virtual->corrupted)
+  {
+    pars_info_t *info= pars_info_create();
+    pars_info_add_ull_literal(info, "id", table.id);
+    if (dberr_t err= que_eval_sql(info,
+                                  "PROCEDURE DROP_VIRTUAL() IS\n"
+                                  "BEGIN\n"
+                                  "DELETE FROM SYS_VIRTUAL"
+                                  " WHERE TABLE_ID=:id;\n"
+                                  "END;\n", this))
+      return err;
+  }
+
+  /* Once DELETE FROM SYS_INDEXES is committed, purge may invoke
+  dict_drop_index_tree(). */
+
+  if (!(table.flags2 & (DICT_TF2_FTS_HAS_DOC_ID | DICT_TF2_FTS)));
+  else if (dberr_t err= fts_drop_tables(this, table))
+  {
+    ib::error() << "Unable to remove FTS tables for "
+                << table.name << ": " << err;
+    return err;
+  }
+
+  mod_tables.emplace(const_cast<dict_table_t*>(&table), undo_no).
+    first->second.set_dropped();
+
+  pars_info_t *info= pars_info_create();
+  pars_info_add_ull_literal(info, "id", table.id);
+  return que_eval_sql(info,
+                      "PROCEDURE DROP_TABLE() IS\n"
+                      "iid CHAR;\n"
+
+                      "DECLARE CURSOR idx IS\n"
+                      "SELECT ID FROM SYS_INDEXES\n"
+                      "WHERE TABLE_ID=:id FOR UPDATE;\n"
+
+                      "BEGIN\n"
+
+                      "DELETE FROM SYS_TABLES WHERE ID=:id;\n"
+                      "DELETE FROM SYS_COLUMNS WHERE TABLE_ID=:id;\n"
+
+                      "OPEN idx;\n"
+                      "WHILE 1 = 1 LOOP\n"
+                      "  FETCH idx INTO iid;\n"
+                      "  IF (SQL % NOTFOUND) THEN EXIT; END IF;\n"
+                      "  DELETE FROM SYS_INDEXES WHERE CURRENT OF idx;\n"
+                      "  DELETE FROM SYS_FIELDS WHERE INDEX_ID=iid;\n"
+                      "END LOOP;\n"
+                      "CLOSE idx;\n"
+
+                      "END;\n", this);
+}
+
+/** Commit the transaction, possibly after drop_table().
+@param deleted   handles of data files that were deleted */
+void trx_t::commit(std::vector<pfs_os_file_t> &deleted)
+{
+  ut_ad(dict_operation);
+  flush_log_later= true;
+  commit_persist();
+  flush_log_later= false;
+  if (dict_operation)
+  {
+    std::vector<uint32_t> space_ids;
+    space_ids.reserve(mod_tables.size());
+    ut_ad(dict_sys.locked());
+    lock_sys.wr_lock(SRW_LOCK_CALL);
+    mutex_lock();
+    lock_release_on_drop(this);
+    ut_ad(UT_LIST_GET_LEN(lock.trx_locks) == 0);
+    ut_ad(ib_vector_is_empty(autoinc_locks));
+    mem_heap_empty(lock.lock_heap);
+    lock.table_locks.clear();
+    /* commit_persist() already reset this. */
+    ut_ad(!lock.was_chosen_as_deadlock_victim);
+    lock.n_rec_locks= 0;
+    while (dict_table_t *table= UT_LIST_GET_FIRST(lock.evicted_tables))
+    {
+      UT_LIST_REMOVE(lock.evicted_tables, table);
+      dict_mem_table_free(table);
+    }
+    dict_operation= false;
+    id= 0;
+    mutex_unlock();
+
+    for (const auto &p : mod_tables)
+    {
+      if (p.second.is_dropped())
+      {
+        dict_table_t *table= p.first;
+        dict_stats_recalc_pool_del(table->id, true);
+        dict_stats_defrag_pool_del(table, nullptr);
+        if (btr_defragment_active)
+          btr_defragment_remove_table(table);
+        const fil_space_t *space= table->space;
+        ut_ad(!p.second.is_aux_table() || purge_sys.must_wait_FTS());
+        dict_sys.remove(table);
+        if (const auto id= space ? space->id : 0)
+        {
+          space_ids.emplace_back(id);
+          pfs_os_file_t d= fil_delete_tablespace(id);
+          if (d != OS_FILE_CLOSED)
+            deleted.emplace_back(d);
+        }
+      }
+    }
+
+    lock_sys.wr_unlock();
+
+    mysql_mutex_lock(&lock_sys.wait_mutex);
+    lock_sys.deadlock_check();
+    mysql_mutex_unlock(&lock_sys.wait_mutex);
+
+    for (const auto id : space_ids)
+      ibuf_delete_for_discarded_space(id);
+  }
+  commit_cleanup();
+}