Adding upstream version 16.2.upstream/16.2

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

1 files changed, 811 insertions, 0 deletions

diff --git a/src/include/access/htup_details.h b/src/include/access/htup_details.h
new file mode 100644
index 0000000..e01f4f3
--- /dev/null
+++ b/src/include/access/htup_details.h
@@ -0,0 +1,811 @@
+/*-------------------------------------------------------------------------
+ *
+ * htup_details.h
+ *	  POSTGRES heap tuple header definitions.
+ *
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/htup_details.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef HTUP_DETAILS_H
+#define HTUP_DETAILS_H
+
+#include "access/htup.h"
+#include "access/transam.h"
+#include "access/tupdesc.h"
+#include "access/tupmacs.h"
+#include "storage/bufpage.h"
+#include "varatt.h"
+
+/*
+ * MaxTupleAttributeNumber limits the number of (user) columns in a tuple.
+ * The key limit on this value is that the size of the fixed overhead for
+ * a tuple, plus the size of the null-values bitmap (at 1 bit per column),
+ * plus MAXALIGN alignment, must fit into t_hoff which is uint8.  On most
+ * machines the upper limit without making t_hoff wider would be a little
+ * over 1700.  We use round numbers here and for MaxHeapAttributeNumber
+ * so that alterations in HeapTupleHeaderData layout won't change the
+ * supported max number of columns.
+ */
+#define MaxTupleAttributeNumber 1664	/* 8 * 208 */
+
+/*
+ * MaxHeapAttributeNumber limits the number of (user) columns in a table.
+ * This should be somewhat less than MaxTupleAttributeNumber.  It must be
+ * at least one less, else we will fail to do UPDATEs on a maximal-width
+ * table (because UPDATE has to form working tuples that include CTID).
+ * In practice we want some additional daylight so that we can gracefully
+ * support operations that add hidden "resjunk" columns, for example
+ * SELECT * FROM wide_table ORDER BY foo, bar, baz.
+ * In any case, depending on column data types you will likely be running
+ * into the disk-block-based limit on overall tuple size if you have more
+ * than a thousand or so columns.  TOAST won't help.
+ */
+#define MaxHeapAttributeNumber	1600	/* 8 * 200 */
+
+/*
+ * Heap tuple header.  To avoid wasting space, the fields should be
+ * laid out in such a way as to avoid structure padding.
+ *
+ * Datums of composite types (row types) share the same general structure
+ * as on-disk tuples, so that the same routines can be used to build and
+ * examine them.  However the requirements are slightly different: a Datum
+ * does not need any transaction visibility information, and it does need
+ * a length word and some embedded type information.  We can achieve this
+ * by overlaying the xmin/cmin/xmax/cmax/xvac fields of a heap tuple
+ * with the fields needed in the Datum case.  Typically, all tuples built
+ * in-memory will be initialized with the Datum fields; but when a tuple is
+ * about to be inserted in a table, the transaction fields will be filled,
+ * overwriting the datum fields.
+ *
+ * The overall structure of a heap tuple looks like:
+ *			fixed fields (HeapTupleHeaderData struct)
+ *			nulls bitmap (if HEAP_HASNULL is set in t_infomask)
+ *			alignment padding (as needed to make user data MAXALIGN'd)
+ *			object ID (if HEAP_HASOID_OLD is set in t_infomask, not created
+ *          anymore)
+ *			user data fields
+ *
+ * We store five "virtual" fields Xmin, Cmin, Xmax, Cmax, and Xvac in three
+ * physical fields.  Xmin and Xmax are always really stored, but Cmin, Cmax
+ * and Xvac share a field.  This works because we know that Cmin and Cmax
+ * are only interesting for the lifetime of the inserting and deleting
+ * transaction respectively.  If a tuple is inserted and deleted in the same
+ * transaction, we store a "combo" command id that can be mapped to the real
+ * cmin and cmax, but only by use of local state within the originating
+ * backend.  See combocid.c for more details.  Meanwhile, Xvac is only set by
+ * old-style VACUUM FULL, which does not have any command sub-structure and so
+ * does not need either Cmin or Cmax.  (This requires that old-style VACUUM
+ * FULL never try to move a tuple whose Cmin or Cmax is still interesting,
+ * ie, an insert-in-progress or delete-in-progress tuple.)
+ *
+ * A word about t_ctid: whenever a new tuple is stored on disk, its t_ctid
+ * is initialized with its own TID (location).  If the tuple is ever updated,
+ * its t_ctid is changed to point to the replacement version of the tuple.  Or
+ * if the tuple is moved from one partition to another, due to an update of
+ * the partition key, t_ctid is set to a special value to indicate that
+ * (see ItemPointerSetMovedPartitions).  Thus, a tuple is the latest version
+ * of its row iff XMAX is invalid or
+ * t_ctid points to itself (in which case, if XMAX is valid, the tuple is
+ * either locked or deleted).  One can follow the chain of t_ctid links
+ * to find the newest version of the row, unless it was moved to a different
+ * partition.  Beware however that VACUUM might
+ * erase the pointed-to (newer) tuple before erasing the pointing (older)
+ * tuple.  Hence, when following a t_ctid link, it is necessary to check
+ * to see if the referenced slot is empty or contains an unrelated tuple.
+ * Check that the referenced tuple has XMIN equal to the referencing tuple's
+ * XMAX to verify that it is actually the descendant version and not an
+ * unrelated tuple stored into a slot recently freed by VACUUM.  If either
+ * check fails, one may assume that there is no live descendant version.
+ *
+ * t_ctid is sometimes used to store a speculative insertion token, instead
+ * of a real TID.  A speculative token is set on a tuple that's being
+ * inserted, until the inserter is sure that it wants to go ahead with the
+ * insertion.  Hence a token should only be seen on a tuple with an XMAX
+ * that's still in-progress, or invalid/aborted.  The token is replaced with
+ * the tuple's real TID when the insertion is confirmed.  One should never
+ * see a speculative insertion token while following a chain of t_ctid links,
+ * because they are not used on updates, only insertions.
+ *
+ * Following the fixed header fields, the nulls bitmap is stored (beginning
+ * at t_bits).  The bitmap is *not* stored if t_infomask shows that there
+ * are no nulls in the tuple.  If an OID field is present (as indicated by
+ * t_infomask), then it is stored just before the user data, which begins at
+ * the offset shown by t_hoff.  Note that t_hoff must be a multiple of
+ * MAXALIGN.
+ */
+
+typedef struct HeapTupleFields
+{
+	TransactionId t_xmin;		/* inserting xact ID */
+	TransactionId t_xmax;		/* deleting or locking xact ID */
+
+	union
+	{
+		CommandId	t_cid;		/* inserting or deleting command ID, or both */
+		TransactionId t_xvac;	/* old-style VACUUM FULL xact ID */
+	}			t_field3;
+} HeapTupleFields;
+
+typedef struct DatumTupleFields
+{
+	int32		datum_len_;		/* varlena header (do not touch directly!) */
+
+	int32		datum_typmod;	/* -1, or identifier of a record type */
+
+	Oid			datum_typeid;	/* composite type OID, or RECORDOID */
+
+	/*
+	 * datum_typeid cannot be a domain over composite, only plain composite,
+	 * even if the datum is meant as a value of a domain-over-composite type.
+	 * This is in line with the general principle that CoerceToDomain does not
+	 * change the physical representation of the base type value.
+	 *
+	 * Note: field ordering is chosen with thought that Oid might someday
+	 * widen to 64 bits.
+	 */
+} DatumTupleFields;
+
+struct HeapTupleHeaderData
+{
+	union
+	{
+		HeapTupleFields t_heap;
+		DatumTupleFields t_datum;
+	}			t_choice;
+
+	ItemPointerData t_ctid;		/* current TID of this or newer tuple (or a
+								 * speculative insertion token) */
+
+	/* Fields below here must match MinimalTupleData! */
+
+#define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK2 2
+	uint16		t_infomask2;	/* number of attributes + various flags */
+
+#define FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK 3
+	uint16		t_infomask;		/* various flag bits, see below */
+
+#define FIELDNO_HEAPTUPLEHEADERDATA_HOFF 4
+	uint8		t_hoff;			/* sizeof header incl. bitmap, padding */
+
+	/* ^ - 23 bytes - ^ */
+
+#define FIELDNO_HEAPTUPLEHEADERDATA_BITS 5
+	bits8		t_bits[FLEXIBLE_ARRAY_MEMBER];	/* bitmap of NULLs */
+
+	/* MORE DATA FOLLOWS AT END OF STRUCT */
+};
+
+/* typedef appears in htup.h */
+
+#define SizeofHeapTupleHeader offsetof(HeapTupleHeaderData, t_bits)
+
+/*
+ * information stored in t_infomask:
+ */
+#define HEAP_HASNULL			0x0001	/* has null attribute(s) */
+#define HEAP_HASVARWIDTH		0x0002	/* has variable-width attribute(s) */
+#define HEAP_HASEXTERNAL		0x0004	/* has external stored attribute(s) */
+#define HEAP_HASOID_OLD			0x0008	/* has an object-id field */
+#define HEAP_XMAX_KEYSHR_LOCK	0x0010	/* xmax is a key-shared locker */
+#define HEAP_COMBOCID			0x0020	/* t_cid is a combo CID */
+#define HEAP_XMAX_EXCL_LOCK		0x0040	/* xmax is exclusive locker */
+#define HEAP_XMAX_LOCK_ONLY		0x0080	/* xmax, if valid, is only a locker */
+
+ /* xmax is a shared locker */
+#define HEAP_XMAX_SHR_LOCK	(HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)
+
+#define HEAP_LOCK_MASK	(HEAP_XMAX_SHR_LOCK | HEAP_XMAX_EXCL_LOCK | \
+						 HEAP_XMAX_KEYSHR_LOCK)
+#define HEAP_XMIN_COMMITTED		0x0100	/* t_xmin committed */
+#define HEAP_XMIN_INVALID		0x0200	/* t_xmin invalid/aborted */
+#define HEAP_XMIN_FROZEN		(HEAP_XMIN_COMMITTED|HEAP_XMIN_INVALID)
+#define HEAP_XMAX_COMMITTED		0x0400	/* t_xmax committed */
+#define HEAP_XMAX_INVALID		0x0800	/* t_xmax invalid/aborted */
+#define HEAP_XMAX_IS_MULTI		0x1000	/* t_xmax is a MultiXactId */
+#define HEAP_UPDATED			0x2000	/* this is UPDATEd version of row */
+#define HEAP_MOVED_OFF			0x4000	/* moved to another place by pre-9.0
+										 * VACUUM FULL; kept for binary
+										 * upgrade support */
+#define HEAP_MOVED_IN			0x8000	/* moved from another place by pre-9.0
+										 * VACUUM FULL; kept for binary
+										 * upgrade support */
+#define HEAP_MOVED (HEAP_MOVED_OFF | HEAP_MOVED_IN)
+
+#define HEAP_XACT_MASK			0xFFF0	/* visibility-related bits */
+
+/*
+ * A tuple is only locked (i.e. not updated by its Xmax) if the
+ * HEAP_XMAX_LOCK_ONLY bit is set; or, for pg_upgrade's sake, if the Xmax is
+ * not a multi and the EXCL_LOCK bit is set.
+ *
+ * See also HeapTupleHeaderIsOnlyLocked, which also checks for a possible
+ * aborted updater transaction.
+ *
+ * Beware of multiple evaluations of the argument.
+ */
+#define HEAP_XMAX_IS_LOCKED_ONLY(infomask) \
+	(((infomask) & HEAP_XMAX_LOCK_ONLY) || \
+	 (((infomask) & (HEAP_XMAX_IS_MULTI | HEAP_LOCK_MASK)) == HEAP_XMAX_EXCL_LOCK))
+
+/*
+ * A tuple that has HEAP_XMAX_IS_MULTI and HEAP_XMAX_LOCK_ONLY but neither of
+ * HEAP_XMAX_EXCL_LOCK and HEAP_XMAX_KEYSHR_LOCK must come from a tuple that was
+ * share-locked in 9.2 or earlier and then pg_upgrade'd.
+ *
+ * In 9.2 and prior, HEAP_XMAX_IS_MULTI was only set when there were multiple
+ * FOR SHARE lockers of that tuple.  That set HEAP_XMAX_LOCK_ONLY (with a
+ * different name back then) but neither of HEAP_XMAX_EXCL_LOCK and
+ * HEAP_XMAX_KEYSHR_LOCK.  That combination is no longer possible in 9.3 and
+ * up, so if we see that combination we know for certain that the tuple was
+ * locked in an earlier release; since all such lockers are gone (they cannot
+ * survive through pg_upgrade), such tuples can safely be considered not
+ * locked.
+ *
+ * We must not resolve such multixacts locally, because the result would be
+ * bogus, regardless of where they stand with respect to the current valid
+ * multixact range.
+ */
+#define HEAP_LOCKED_UPGRADED(infomask) \
+( \
+	 ((infomask) & HEAP_XMAX_IS_MULTI) != 0 && \
+	 ((infomask) & HEAP_XMAX_LOCK_ONLY) != 0 && \
+	 (((infomask) & (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)) == 0) \
+)
+
+/*
+ * Use these to test whether a particular lock is applied to a tuple
+ */
+#define HEAP_XMAX_IS_SHR_LOCKED(infomask) \
+	(((infomask) & HEAP_LOCK_MASK) == HEAP_XMAX_SHR_LOCK)
+#define HEAP_XMAX_IS_EXCL_LOCKED(infomask) \
+	(((infomask) & HEAP_LOCK_MASK) == HEAP_XMAX_EXCL_LOCK)
+#define HEAP_XMAX_IS_KEYSHR_LOCKED(infomask) \
+	(((infomask) & HEAP_LOCK_MASK) == HEAP_XMAX_KEYSHR_LOCK)
+
+/* turn these all off when Xmax is to change */
+#define HEAP_XMAX_BITS (HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID | \
+						HEAP_XMAX_IS_MULTI | HEAP_LOCK_MASK | HEAP_XMAX_LOCK_ONLY)
+
+/*
+ * information stored in t_infomask2:
+ */
+#define HEAP_NATTS_MASK			0x07FF	/* 11 bits for number of attributes */
+/* bits 0x1800 are available */
+#define HEAP_KEYS_UPDATED		0x2000	/* tuple was updated and key cols
+										 * modified, or tuple deleted */
+#define HEAP_HOT_UPDATED		0x4000	/* tuple was HOT-updated */
+#define HEAP_ONLY_TUPLE			0x8000	/* this is heap-only tuple */
+
+#define HEAP2_XACT_MASK			0xE000	/* visibility-related bits */
+
+/*
+ * HEAP_TUPLE_HAS_MATCH is a temporary flag used during hash joins.  It is
+ * only used in tuples that are in the hash table, and those don't need
+ * any visibility information, so we can overlay it on a visibility flag
+ * instead of using up a dedicated bit.
+ */
+#define HEAP_TUPLE_HAS_MATCH	HEAP_ONLY_TUPLE /* tuple has a join match */
+
+/*
+ * HeapTupleHeader accessor macros
+ *
+ * Note: beware of multiple evaluations of "tup" argument.  But the Set
+ * macros evaluate their other argument only once.
+ */
+
+/*
+ * HeapTupleHeaderGetRawXmin returns the "raw" xmin field, which is the xid
+ * originally used to insert the tuple.  However, the tuple might actually
+ * be frozen (via HeapTupleHeaderSetXminFrozen) in which case the tuple's xmin
+ * is visible to every snapshot.  Prior to PostgreSQL 9.4, we actually changed
+ * the xmin to FrozenTransactionId, and that value may still be encountered
+ * on disk.
+ */
+#define HeapTupleHeaderGetRawXmin(tup) \
+( \
+	(tup)->t_choice.t_heap.t_xmin \
+)
+
+#define HeapTupleHeaderGetXmin(tup) \
+( \
+	HeapTupleHeaderXminFrozen(tup) ? \
+		FrozenTransactionId : HeapTupleHeaderGetRawXmin(tup) \
+)
+
+#define HeapTupleHeaderSetXmin(tup, xid) \
+( \
+	(tup)->t_choice.t_heap.t_xmin = (xid) \
+)
+
+#define HeapTupleHeaderXminCommitted(tup) \
+( \
+	((tup)->t_infomask & HEAP_XMIN_COMMITTED) != 0 \
+)
+
+#define HeapTupleHeaderXminInvalid(tup) \
+( \
+	((tup)->t_infomask & (HEAP_XMIN_COMMITTED|HEAP_XMIN_INVALID)) == \
+		HEAP_XMIN_INVALID \
+)
+
+#define HeapTupleHeaderXminFrozen(tup) \
+( \
+	((tup)->t_infomask & (HEAP_XMIN_FROZEN)) == HEAP_XMIN_FROZEN \
+)
+
+#define HeapTupleHeaderSetXminCommitted(tup) \
+( \
+	AssertMacro(!HeapTupleHeaderXminInvalid(tup)), \
+	((tup)->t_infomask |= HEAP_XMIN_COMMITTED) \
+)
+
+#define HeapTupleHeaderSetXminInvalid(tup) \
+( \
+	AssertMacro(!HeapTupleHeaderXminCommitted(tup)), \
+	((tup)->t_infomask |= HEAP_XMIN_INVALID) \
+)
+
+#define HeapTupleHeaderSetXminFrozen(tup) \
+( \
+	AssertMacro(!HeapTupleHeaderXminInvalid(tup)), \
+	((tup)->t_infomask |= HEAP_XMIN_FROZEN) \
+)
+
+/*
+ * HeapTupleHeaderGetRawXmax gets you the raw Xmax field.  To find out the Xid
+ * that updated a tuple, you might need to resolve the MultiXactId if certain
+ * bits are set.  HeapTupleHeaderGetUpdateXid checks those bits and takes care
+ * to resolve the MultiXactId if necessary.  This might involve multixact I/O,
+ * so it should only be used if absolutely necessary.
+ */
+#define HeapTupleHeaderGetUpdateXid(tup) \
+( \
+	(!((tup)->t_infomask & HEAP_XMAX_INVALID) && \
+	 ((tup)->t_infomask & HEAP_XMAX_IS_MULTI) && \
+	 !((tup)->t_infomask & HEAP_XMAX_LOCK_ONLY)) ? \
+		HeapTupleGetUpdateXid(tup) \
+	: \
+		HeapTupleHeaderGetRawXmax(tup) \
+)
+
+#define HeapTupleHeaderGetRawXmax(tup) \
+( \
+	(tup)->t_choice.t_heap.t_xmax \
+)
+
+#define HeapTupleHeaderSetXmax(tup, xid) \
+( \
+	(tup)->t_choice.t_heap.t_xmax = (xid) \
+)
+
+/*
+ * HeapTupleHeaderGetRawCommandId will give you what's in the header whether
+ * it is useful or not.  Most code should use HeapTupleHeaderGetCmin or
+ * HeapTupleHeaderGetCmax instead, but note that those Assert that you can
+ * get a legitimate result, ie you are in the originating transaction!
+ */
+#define HeapTupleHeaderGetRawCommandId(tup) \
+( \
+	(tup)->t_choice.t_heap.t_field3.t_cid \
+)
+
+/* SetCmin is reasonably simple since we never need a combo CID */
+#define HeapTupleHeaderSetCmin(tup, cid) \
+do { \
+	Assert(!((tup)->t_infomask & HEAP_MOVED)); \
+	(tup)->t_choice.t_heap.t_field3.t_cid = (cid); \
+	(tup)->t_infomask &= ~HEAP_COMBOCID; \
+} while (0)
+
+/* SetCmax must be used after HeapTupleHeaderAdjustCmax; see combocid.c */
+#define HeapTupleHeaderSetCmax(tup, cid, iscombo) \
+do { \
+	Assert(!((tup)->t_infomask & HEAP_MOVED)); \
+	(tup)->t_choice.t_heap.t_field3.t_cid = (cid); \
+	if (iscombo) \
+		(tup)->t_infomask |= HEAP_COMBOCID; \
+	else \
+		(tup)->t_infomask &= ~HEAP_COMBOCID; \
+} while (0)
+
+#define HeapTupleHeaderGetXvac(tup) \
+( \
+	((tup)->t_infomask & HEAP_MOVED) ? \
+		(tup)->t_choice.t_heap.t_field3.t_xvac \
+	: \
+		InvalidTransactionId \
+)
+
+#define HeapTupleHeaderSetXvac(tup, xid) \
+do { \
+	Assert((tup)->t_infomask & HEAP_MOVED); \
+	(tup)->t_choice.t_heap.t_field3.t_xvac = (xid); \
+} while (0)
+
+StaticAssertDecl(MaxOffsetNumber < SpecTokenOffsetNumber,
+				 "invalid speculative token constant");
+
+#define HeapTupleHeaderIsSpeculative(tup) \
+( \
+	(ItemPointerGetOffsetNumberNoCheck(&(tup)->t_ctid) == SpecTokenOffsetNumber) \
+)
+
+#define HeapTupleHeaderGetSpeculativeToken(tup) \
+( \
+	AssertMacro(HeapTupleHeaderIsSpeculative(tup)), \
+	ItemPointerGetBlockNumber(&(tup)->t_ctid) \
+)
+
+#define HeapTupleHeaderSetSpeculativeToken(tup, token)	\
+( \
+	ItemPointerSet(&(tup)->t_ctid, token, SpecTokenOffsetNumber) \
+)
+
+#define HeapTupleHeaderIndicatesMovedPartitions(tup) \
+	ItemPointerIndicatesMovedPartitions(&(tup)->t_ctid)
+
+#define HeapTupleHeaderSetMovedPartitions(tup) \
+	ItemPointerSetMovedPartitions(&(tup)->t_ctid)
+
+#define HeapTupleHeaderGetDatumLength(tup) \
+	VARSIZE(tup)
+
+#define HeapTupleHeaderSetDatumLength(tup, len) \
+	SET_VARSIZE(tup, len)
+
+#define HeapTupleHeaderGetTypeId(tup) \
+( \
+	(tup)->t_choice.t_datum.datum_typeid \
+)
+
+#define HeapTupleHeaderSetTypeId(tup, typeid) \
+( \
+	(tup)->t_choice.t_datum.datum_typeid = (typeid) \
+)
+
+#define HeapTupleHeaderGetTypMod(tup) \
+( \
+	(tup)->t_choice.t_datum.datum_typmod \
+)
+
+#define HeapTupleHeaderSetTypMod(tup, typmod) \
+( \
+	(tup)->t_choice.t_datum.datum_typmod = (typmod) \
+)
+
+/*
+ * Note that we stop considering a tuple HOT-updated as soon as it is known
+ * aborted or the would-be updating transaction is known aborted.  For best
+ * efficiency, check tuple visibility before using this macro, so that the
+ * INVALID bits will be as up to date as possible.
+ */
+#define HeapTupleHeaderIsHotUpdated(tup) \
+( \
+	((tup)->t_infomask2 & HEAP_HOT_UPDATED) != 0 && \
+	((tup)->t_infomask & HEAP_XMAX_INVALID) == 0 && \
+	!HeapTupleHeaderXminInvalid(tup) \
+)
+
+#define HeapTupleHeaderSetHotUpdated(tup) \
+( \
+	(tup)->t_infomask2 |= HEAP_HOT_UPDATED \
+)
+
+#define HeapTupleHeaderClearHotUpdated(tup) \
+( \
+	(tup)->t_infomask2 &= ~HEAP_HOT_UPDATED \
+)
+
+#define HeapTupleHeaderIsHeapOnly(tup) \
+( \
+  ((tup)->t_infomask2 & HEAP_ONLY_TUPLE) != 0 \
+)
+
+#define HeapTupleHeaderSetHeapOnly(tup) \
+( \
+  (tup)->t_infomask2 |= HEAP_ONLY_TUPLE \
+)
+
+#define HeapTupleHeaderClearHeapOnly(tup) \
+( \
+  (tup)->t_infomask2 &= ~HEAP_ONLY_TUPLE \
+)
+
+#define HeapTupleHeaderHasMatch(tup) \
+( \
+  ((tup)->t_infomask2 & HEAP_TUPLE_HAS_MATCH) != 0 \
+)
+
+#define HeapTupleHeaderSetMatch(tup) \
+( \
+  (tup)->t_infomask2 |= HEAP_TUPLE_HAS_MATCH \
+)
+
+#define HeapTupleHeaderClearMatch(tup) \
+( \
+  (tup)->t_infomask2 &= ~HEAP_TUPLE_HAS_MATCH \
+)
+
+#define HeapTupleHeaderGetNatts(tup) \
+	((tup)->t_infomask2 & HEAP_NATTS_MASK)
+
+#define HeapTupleHeaderSetNatts(tup, natts) \
+( \
+	(tup)->t_infomask2 = ((tup)->t_infomask2 & ~HEAP_NATTS_MASK) | (natts) \
+)
+
+#define HeapTupleHeaderHasExternal(tup) \
+		(((tup)->t_infomask & HEAP_HASEXTERNAL) != 0)
+
+
+/*
+ * BITMAPLEN(NATTS) -
+ *		Computes size of null bitmap given number of data columns.
+ */
+#define BITMAPLEN(NATTS)	(((int)(NATTS) + 7) / 8)
+
+/*
+ * MaxHeapTupleSize is the maximum allowed size of a heap tuple, including
+ * header and MAXALIGN alignment padding.  Basically it's BLCKSZ minus the
+ * other stuff that has to be on a disk page.  Since heap pages use no
+ * "special space", there's no deduction for that.
+ *
+ * NOTE: we allow for the ItemId that must point to the tuple, ensuring that
+ * an otherwise-empty page can indeed hold a tuple of this size.  Because
+ * ItemIds and tuples have different alignment requirements, don't assume that
+ * you can, say, fit 2 tuples of size MaxHeapTupleSize/2 on the same page.
+ */
+#define MaxHeapTupleSize  (BLCKSZ - MAXALIGN(SizeOfPageHeaderData + sizeof(ItemIdData)))
+#define MinHeapTupleSize  MAXALIGN(SizeofHeapTupleHeader)
+
+/*
+ * MaxHeapTuplesPerPage is an upper bound on the number of tuples that can
+ * fit on one heap page.  (Note that indexes could have more, because they
+ * use a smaller tuple header.)  We arrive at the divisor because each tuple
+ * must be maxaligned, and it must have an associated line pointer.
+ *
+ * Note: with HOT, there could theoretically be more line pointers (not actual
+ * tuples) than this on a heap page.  However we constrain the number of line
+ * pointers to this anyway, to avoid excessive line-pointer bloat and not
+ * require increases in the size of work arrays.
+ */
+#define MaxHeapTuplesPerPage	\
+	((int) ((BLCKSZ - SizeOfPageHeaderData) / \
+			(MAXALIGN(SizeofHeapTupleHeader) + sizeof(ItemIdData))))
+
+/*
+ * MaxAttrSize is a somewhat arbitrary upper limit on the declared size of
+ * data fields of char(n) and similar types.  It need not have anything
+ * directly to do with the *actual* upper limit of varlena values, which
+ * is currently 1Gb (see TOAST structures in postgres.h).  I've set it
+ * at 10Mb which seems like a reasonable number --- tgl 8/6/00.
+ */
+#define MaxAttrSize		(10 * 1024 * 1024)
+
+
+/*
+ * MinimalTuple is an alternative representation that is used for transient
+ * tuples inside the executor, in places where transaction status information
+ * is not required, the tuple rowtype is known, and shaving off a few bytes
+ * is worthwhile because we need to store many tuples.  The representation
+ * is chosen so that tuple access routines can work with either full or
+ * minimal tuples via a HeapTupleData pointer structure.  The access routines
+ * see no difference, except that they must not access the transaction status
+ * or t_ctid fields because those aren't there.
+ *
+ * For the most part, MinimalTuples should be accessed via TupleTableSlot
+ * routines.  These routines will prevent access to the "system columns"
+ * and thereby prevent accidental use of the nonexistent fields.
+ *
+ * MinimalTupleData contains a length word, some padding, and fields matching
+ * HeapTupleHeaderData beginning with t_infomask2. The padding is chosen so
+ * that offsetof(t_infomask2) is the same modulo MAXIMUM_ALIGNOF in both
+ * structs.   This makes data alignment rules equivalent in both cases.
+ *
+ * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is
+ * set to point MINIMAL_TUPLE_OFFSET bytes before the actual start of the
+ * minimal tuple --- that is, where a full tuple matching the minimal tuple's
+ * data would start.  This trick is what makes the structs seem equivalent.
+ *
+ * Note that t_hoff is computed the same as in a full tuple, hence it includes
+ * the MINIMAL_TUPLE_OFFSET distance.  t_len does not include that, however.
+ *
+ * MINIMAL_TUPLE_DATA_OFFSET is the offset to the first useful (non-pad) data
+ * other than the length word.  tuplesort.c and tuplestore.c use this to avoid
+ * writing the padding to disk.
+ */
+#define MINIMAL_TUPLE_OFFSET \
+	((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF)
+#define MINIMAL_TUPLE_PADDING \
+	((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF)
+#define MINIMAL_TUPLE_DATA_OFFSET \
+	offsetof(MinimalTupleData, t_infomask2)
+
+struct MinimalTupleData
+{
+	uint32		t_len;			/* actual length of minimal tuple */
+
+	char		mt_padding[MINIMAL_TUPLE_PADDING];
+
+	/* Fields below here must match HeapTupleHeaderData! */
+
+	uint16		t_infomask2;	/* number of attributes + various flags */
+
+	uint16		t_infomask;		/* various flag bits, see below */
+
+	uint8		t_hoff;			/* sizeof header incl. bitmap, padding */
+
+	/* ^ - 23 bytes - ^ */
+
+	bits8		t_bits[FLEXIBLE_ARRAY_MEMBER];	/* bitmap of NULLs */
+
+	/* MORE DATA FOLLOWS AT END OF STRUCT */
+};
+
+/* typedef appears in htup.h */
+
+#define SizeofMinimalTupleHeader offsetof(MinimalTupleData, t_bits)
+
+
+/*
+ * GETSTRUCT - given a HeapTuple pointer, return address of the user data
+ */
+#define GETSTRUCT(TUP) ((char *) ((TUP)->t_data) + (TUP)->t_data->t_hoff)
+
+/*
+ * Accessor macros to be used with HeapTuple pointers.
+ */
+
+#define HeapTupleHasNulls(tuple) \
+		(((tuple)->t_data->t_infomask & HEAP_HASNULL) != 0)
+
+#define HeapTupleNoNulls(tuple) \
+		(!((tuple)->t_data->t_infomask & HEAP_HASNULL))
+
+#define HeapTupleHasVarWidth(tuple) \
+		(((tuple)->t_data->t_infomask & HEAP_HASVARWIDTH) != 0)
+
+#define HeapTupleAllFixed(tuple) \
+		(!((tuple)->t_data->t_infomask & HEAP_HASVARWIDTH))
+
+#define HeapTupleHasExternal(tuple) \
+		(((tuple)->t_data->t_infomask & HEAP_HASEXTERNAL) != 0)
+
+#define HeapTupleIsHotUpdated(tuple) \
+		HeapTupleHeaderIsHotUpdated((tuple)->t_data)
+
+#define HeapTupleSetHotUpdated(tuple) \
+		HeapTupleHeaderSetHotUpdated((tuple)->t_data)
+
+#define HeapTupleClearHotUpdated(tuple) \
+		HeapTupleHeaderClearHotUpdated((tuple)->t_data)
+
+#define HeapTupleIsHeapOnly(tuple) \
+		HeapTupleHeaderIsHeapOnly((tuple)->t_data)
+
+#define HeapTupleSetHeapOnly(tuple) \
+		HeapTupleHeaderSetHeapOnly((tuple)->t_data)
+
+#define HeapTupleClearHeapOnly(tuple) \
+		HeapTupleHeaderClearHeapOnly((tuple)->t_data)
+
+/* prototypes for functions in common/heaptuple.c */
+extern Size heap_compute_data_size(TupleDesc tupleDesc,
+								   Datum *values, bool *isnull);
+extern void heap_fill_tuple(TupleDesc tupleDesc,
+							Datum *values, bool *isnull,
+							char *data, Size data_size,
+							uint16 *infomask, bits8 *bit);
+extern bool heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc);
+extern Datum nocachegetattr(HeapTuple tup, int attnum,
+							TupleDesc tupleDesc);
+extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
+							 bool *isnull);
+extern Datum getmissingattr(TupleDesc tupleDesc,
+							int attnum, bool *isnull);
+extern HeapTuple heap_copytuple(HeapTuple tuple);
+extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
+extern Datum heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc);
+extern HeapTuple heap_form_tuple(TupleDesc tupleDescriptor,
+								 Datum *values, bool *isnull);
+extern HeapTuple heap_modify_tuple(HeapTuple tuple,
+								   TupleDesc tupleDesc,
+								   Datum *replValues,
+								   bool *replIsnull,
+								   bool *doReplace);
+extern HeapTuple heap_modify_tuple_by_cols(HeapTuple tuple,
+										   TupleDesc tupleDesc,
+										   int nCols,
+										   int *replCols,
+										   Datum *replValues,
+										   bool *replIsnull);
+extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
+							  Datum *values, bool *isnull);
+extern void heap_freetuple(HeapTuple htup);
+extern MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor,
+											Datum *values, bool *isnull);
+extern void heap_free_minimal_tuple(MinimalTuple mtup);
+extern MinimalTuple heap_copy_minimal_tuple(MinimalTuple mtup);
+extern HeapTuple heap_tuple_from_minimal_tuple(MinimalTuple mtup);
+extern MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup);
+extern size_t varsize_any(void *p);
+extern HeapTuple heap_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
+extern MinimalTuple minimal_expand_tuple(HeapTuple sourceTuple, TupleDesc tupleDesc);
+
+#ifndef FRONTEND
+/*
+ *	fastgetattr
+ *		Fetch a user attribute's value as a Datum (might be either a
+ *		value, or a pointer into the data area of the tuple).
+ *
+ *		This must not be used when a system attribute might be requested.
+ *		Furthermore, the passed attnum MUST be valid.  Use heap_getattr()
+ *		instead, if in doubt.
+ *
+ *		This gets called many times, so we macro the cacheable and NULL
+ *		lookups, and call nocachegetattr() for the rest.
+ */
+static inline Datum
+fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
+{
+	Assert(attnum > 0);
+
+	*isnull = false;
+	if (HeapTupleNoNulls(tup))
+	{
+		Form_pg_attribute att;
+
+		att = TupleDescAttr(tupleDesc, attnum - 1);
+		if (att->attcacheoff >= 0)
+			return fetchatt(att, (char *) tup->t_data + tup->t_data->t_hoff +
+							att->attcacheoff);
+		else
+			return nocachegetattr(tup, attnum, tupleDesc);
+	}
+	else
+	{
+		if (att_isnull(attnum - 1, tup->t_data->t_bits))
+		{
+			*isnull = true;
+			return (Datum) NULL;
+		}
+		else
+			return nocachegetattr(tup, attnum, tupleDesc);
+	}
+}
+
+/*
+ *	heap_getattr
+ *		Extract an attribute of a heap tuple and return it as a Datum.
+ *		This works for either system or user attributes.  The given attnum
+ *		is properly range-checked.
+ *
+ *		If the field in question has a NULL value, we return a zero Datum
+ *		and set *isnull == true.  Otherwise, we set *isnull == false.
+ *
+ *		<tup> is the pointer to the heap tuple.  <attnum> is the attribute
+ *		number of the column (field) caller wants.  <tupleDesc> is a
+ *		pointer to the structure describing the row and all its fields.
+ *
+ */
+static inline Datum
+heap_getattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
+{
+	if (attnum > 0)
+	{
+		if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
+			return getmissingattr(tupleDesc, attnum, isnull);
+		else
+			return fastgetattr(tup, attnum, tupleDesc, isnull);
+	}
+	else
+		return heap_getsysattr(tup, attnum, tupleDesc, isnull);
+}
+#endif							/* FRONTEND */
+
+#endif							/* HTUP_DETAILS_H */