Adding upstream version 14.5.upstream/14.5upstream

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

1 files changed, 1110 insertions, 0 deletions

diff --git a/src/include/pgstat.h b/src/include/pgstat.h
new file mode 100644
index 0000000..9a90bd8
--- /dev/null
+++ b/src/include/pgstat.h
@@ -0,0 +1,1110 @@
+/* ----------
+ *	pgstat.h
+ *
+ *	Definitions for the PostgreSQL statistics collector daemon.
+ *
+ *	Copyright (c) 2001-2021, PostgreSQL Global Development Group
+ *
+ *	src/include/pgstat.h
+ * ----------
+ */
+#ifndef PGSTAT_H
+#define PGSTAT_H
+
+#include "datatype/timestamp.h"
+#include "portability/instr_time.h"
+#include "postmaster/pgarch.h"	/* for MAX_XFN_CHARS */
+#include "utils/backend_progress.h" /* for backward compatibility */
+#include "utils/backend_status.h"	/* for backward compatibility */
+#include "utils/hsearch.h"
+#include "utils/relcache.h"
+#include "utils/wait_event.h"	/* for backward compatibility */
+
+
+/* ----------
+ * Paths for the statistics files (relative to installation's $PGDATA).
+ * ----------
+ */
+#define PGSTAT_STAT_PERMANENT_DIRECTORY		"pg_stat"
+#define PGSTAT_STAT_PERMANENT_FILENAME		"pg_stat/global.stat"
+#define PGSTAT_STAT_PERMANENT_TMPFILE		"pg_stat/global.tmp"
+
+/* Default directory to store temporary statistics data in */
+#define PG_STAT_TMP_DIR		"pg_stat_tmp"
+
+/* Values for track_functions GUC variable --- order is significant! */
+typedef enum TrackFunctionsLevel
+{
+	TRACK_FUNC_OFF,
+	TRACK_FUNC_PL,
+	TRACK_FUNC_ALL
+}			TrackFunctionsLevel;
+
+/* Values to track the cause of session termination */
+typedef enum SessionEndType
+{
+	DISCONNECT_NOT_YET,			/* still active */
+	DISCONNECT_NORMAL,
+	DISCONNECT_CLIENT_EOF,
+	DISCONNECT_FATAL,
+	DISCONNECT_KILLED
+} SessionEndType;
+
+/* ----------
+ * The types of backend -> collector messages
+ * ----------
+ */
+typedef enum StatMsgType
+{
+	PGSTAT_MTYPE_DUMMY,
+	PGSTAT_MTYPE_INQUIRY,
+	PGSTAT_MTYPE_TABSTAT,
+	PGSTAT_MTYPE_TABPURGE,
+	PGSTAT_MTYPE_DROPDB,
+	PGSTAT_MTYPE_RESETCOUNTER,
+	PGSTAT_MTYPE_RESETSHAREDCOUNTER,
+	PGSTAT_MTYPE_RESETSINGLECOUNTER,
+	PGSTAT_MTYPE_RESETSLRUCOUNTER,
+	PGSTAT_MTYPE_RESETREPLSLOTCOUNTER,
+	PGSTAT_MTYPE_AUTOVAC_START,
+	PGSTAT_MTYPE_VACUUM,
+	PGSTAT_MTYPE_ANALYZE,
+	PGSTAT_MTYPE_ARCHIVER,
+	PGSTAT_MTYPE_BGWRITER,
+	PGSTAT_MTYPE_WAL,
+	PGSTAT_MTYPE_SLRU,
+	PGSTAT_MTYPE_FUNCSTAT,
+	PGSTAT_MTYPE_FUNCPURGE,
+	PGSTAT_MTYPE_RECOVERYCONFLICT,
+	PGSTAT_MTYPE_TEMPFILE,
+	PGSTAT_MTYPE_DEADLOCK,
+	PGSTAT_MTYPE_CHECKSUMFAILURE,
+	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECT,
+	PGSTAT_MTYPE_DISCONNECT,
+} StatMsgType;
+
+/* ----------
+ * The data type used for counters.
+ * ----------
+ */
+typedef int64 PgStat_Counter;
+
+/* ----------
+ * PgStat_TableCounts			The actual per-table counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ * It is a component of PgStat_TableStatus (within-backend state) and
+ * PgStat_TableEntry (the transmitted message format).
+ *
+ * Note: for a table, tuples_returned is the number of tuples successfully
+ * fetched by heap_getnext, while tuples_fetched is the number of tuples
+ * successfully fetched by heap_fetch under the control of bitmap indexscans.
+ * For an index, tuples_returned is the number of index entries returned by
+ * the index AM, while tuples_fetched is the number of tuples successfully
+ * fetched by heap_fetch under the control of simple indexscans for this index.
+ *
+ * tuples_inserted/updated/deleted/hot_updated count attempted actions,
+ * regardless of whether the transaction committed.  delta_live_tuples,
+ * delta_dead_tuples, and changed_tuples are set depending on commit or abort.
+ * Note that delta_live_tuples and delta_dead_tuples can be negative!
+ * ----------
+ */
+typedef struct PgStat_TableCounts
+{
+	PgStat_Counter t_numscans;
+
+	PgStat_Counter t_tuples_returned;
+	PgStat_Counter t_tuples_fetched;
+
+	PgStat_Counter t_tuples_inserted;
+	PgStat_Counter t_tuples_updated;
+	PgStat_Counter t_tuples_deleted;
+	PgStat_Counter t_tuples_hot_updated;
+	bool		t_truncated;
+
+	PgStat_Counter t_delta_live_tuples;
+	PgStat_Counter t_delta_dead_tuples;
+	PgStat_Counter t_changed_tuples;
+
+	PgStat_Counter t_blocks_fetched;
+	PgStat_Counter t_blocks_hit;
+} PgStat_TableCounts;
+
+/* Possible targets for resetting cluster-wide shared values */
+typedef enum PgStat_Shared_Reset_Target
+{
+	RESET_ARCHIVER,
+	RESET_BGWRITER,
+	RESET_WAL
+} PgStat_Shared_Reset_Target;
+
+/* Possible object types for resetting single counters */
+typedef enum PgStat_Single_Reset_Type
+{
+	RESET_TABLE,
+	RESET_FUNCTION
+} PgStat_Single_Reset_Type;
+
+/* ------------------------------------------------------------
+ * Structures kept in backend local memory while accumulating counts
+ * ------------------------------------------------------------
+ */
+
+
+/* ----------
+ * PgStat_TableStatus			Per-table status within a backend
+ *
+ * Many of the event counters are nontransactional, ie, we count events
+ * in committed and aborted transactions alike.  For these, we just count
+ * directly in the PgStat_TableStatus.  However, delta_live_tuples,
+ * delta_dead_tuples, and changed_tuples must be derived from event counts
+ * with awareness of whether the transaction or subtransaction committed or
+ * aborted.  Hence, we also keep a stack of per-(sub)transaction status
+ * records for every table modified in the current transaction.  At commit
+ * or abort, we propagate tuples_inserted/updated/deleted up to the
+ * parent subtransaction level, or out to the parent PgStat_TableStatus,
+ * as appropriate.
+ * ----------
+ */
+typedef struct PgStat_TableStatus
+{
+	Oid			t_id;			/* table's OID */
+	bool		t_shared;		/* is it a shared catalog? */
+	struct PgStat_TableXactStatus *trans;	/* lowest subxact's counts */
+	PgStat_TableCounts t_counts;	/* event counts to be sent */
+} PgStat_TableStatus;
+
+/* ----------
+ * PgStat_TableXactStatus		Per-table, per-subtransaction status
+ * ----------
+ */
+typedef struct PgStat_TableXactStatus
+{
+	PgStat_Counter tuples_inserted; /* tuples inserted in (sub)xact */
+	PgStat_Counter tuples_updated;	/* tuples updated in (sub)xact */
+	PgStat_Counter tuples_deleted;	/* tuples deleted in (sub)xact */
+	bool		truncated;		/* relation truncated in this (sub)xact */
+	PgStat_Counter inserted_pre_trunc;	/* tuples inserted prior to truncate */
+	PgStat_Counter updated_pre_trunc;	/* tuples updated prior to truncate */
+	PgStat_Counter deleted_pre_trunc;	/* tuples deleted prior to truncate */
+	int			nest_level;		/* subtransaction nest level */
+	/* links to other structs for same relation: */
+	struct PgStat_TableXactStatus *upper;	/* next higher subxact if any */
+	PgStat_TableStatus *parent; /* per-table status */
+	/* structs of same subxact level are linked here: */
+	struct PgStat_TableXactStatus *next;	/* next of same subxact */
+} PgStat_TableXactStatus;
+
+
+/* ------------------------------------------------------------
+ * Message formats follow
+ * ------------------------------------------------------------
+ */
+
+
+/* ----------
+ * PgStat_MsgHdr				The common message header
+ * ----------
+ */
+typedef struct PgStat_MsgHdr
+{
+	StatMsgType m_type;
+	int			m_size;
+} PgStat_MsgHdr;
+
+/* ----------
+ * Space available in a message.  This will keep the UDP packets below 1K,
+ * which should fit unfragmented into the MTU of the loopback interface.
+ * (Larger values of PGSTAT_MAX_MSG_SIZE would work for that on most
+ * platforms, but we're being conservative here.)
+ * ----------
+ */
+#define PGSTAT_MAX_MSG_SIZE 1000
+#define PGSTAT_MSG_PAYLOAD	(PGSTAT_MAX_MSG_SIZE - sizeof(PgStat_MsgHdr))
+
+
+/* ----------
+ * PgStat_MsgDummy				A dummy message, ignored by the collector
+ * ----------
+ */
+typedef struct PgStat_MsgDummy
+{
+	PgStat_MsgHdr m_hdr;
+} PgStat_MsgDummy;
+
+
+/* ----------
+ * PgStat_MsgInquiry			Sent by a backend to ask the collector
+ *								to write the stats file(s).
+ *
+ * Ordinarily, an inquiry message prompts writing of the global stats file,
+ * the stats file for shared catalogs, and the stats file for the specified
+ * database.  If databaseid is InvalidOid, only the first two are written.
+ *
+ * New file(s) will be written only if the existing file has a timestamp
+ * older than the specified cutoff_time; this prevents duplicated effort
+ * when multiple requests arrive at nearly the same time, assuming that
+ * backends send requests with cutoff_times a little bit in the past.
+ *
+ * clock_time should be the requestor's current local time; the collector
+ * uses this to check for the system clock going backward, but it has no
+ * effect unless that occurs.  We assume clock_time >= cutoff_time, though.
+ * ----------
+ */
+
+typedef struct PgStat_MsgInquiry
+{
+	PgStat_MsgHdr m_hdr;
+	TimestampTz clock_time;		/* observed local clock time */
+	TimestampTz cutoff_time;	/* minimum acceptable file timestamp */
+	Oid			databaseid;		/* requested DB (InvalidOid => shared only) */
+} PgStat_MsgInquiry;
+
+
+/* ----------
+ * PgStat_TableEntry			Per-table info in a MsgTabstat
+ * ----------
+ */
+typedef struct PgStat_TableEntry
+{
+	Oid			t_id;
+	PgStat_TableCounts t_counts;
+} PgStat_TableEntry;
+
+/* ----------
+ * PgStat_MsgTabstat			Sent by the backend to report table
+ *								and buffer access statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TABENTRIES  \
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - 3 * sizeof(int) - 5 * sizeof(PgStat_Counter)) \
+	 / sizeof(PgStat_TableEntry))
+
+typedef struct PgStat_MsgTabstat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	int			m_xact_commit;
+	int			m_xact_rollback;
+	PgStat_Counter m_block_read_time;	/* times in microseconds */
+	PgStat_Counter m_block_write_time;
+	PgStat_Counter m_session_time;
+	PgStat_Counter m_active_time;
+	PgStat_Counter m_idle_in_xact_time;
+	PgStat_TableEntry m_entry[PGSTAT_NUM_TABENTRIES];
+} PgStat_MsgTabstat;
+
+
+/* ----------
+ * PgStat_MsgTabpurge			Sent by the backend to tell the collector
+ *								about dead tables.
+ * ----------
+ */
+#define PGSTAT_NUM_TABPURGE  \
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(Oid))
+
+typedef struct PgStat_MsgTabpurge
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	Oid			m_tableid[PGSTAT_NUM_TABPURGE];
+} PgStat_MsgTabpurge;
+
+
+/* ----------
+ * PgStat_MsgDropdb				Sent by the backend to tell the collector
+ *								about a dropped database
+ * ----------
+ */
+typedef struct PgStat_MsgDropdb
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+} PgStat_MsgDropdb;
+
+
+/* ----------
+ * PgStat_MsgResetcounter		Sent by the backend to tell the collector
+ *								to reset counters
+ * ----------
+ */
+typedef struct PgStat_MsgResetcounter
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+} PgStat_MsgResetcounter;
+
+/* ----------
+ * PgStat_MsgResetsharedcounter Sent by the backend to tell the collector
+ *								to reset a shared counter
+ * ----------
+ */
+typedef struct PgStat_MsgResetsharedcounter
+{
+	PgStat_MsgHdr m_hdr;
+	PgStat_Shared_Reset_Target m_resettarget;
+} PgStat_MsgResetsharedcounter;
+
+/* ----------
+ * PgStat_MsgResetsinglecounter Sent by the backend to tell the collector
+ *								to reset a single counter
+ * ----------
+ */
+typedef struct PgStat_MsgResetsinglecounter
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	PgStat_Single_Reset_Type m_resettype;
+	Oid			m_objectid;
+} PgStat_MsgResetsinglecounter;
+
+/* ----------
+ * PgStat_MsgResetslrucounter Sent by the backend to tell the collector
+ *								to reset a SLRU counter
+ * ----------
+ */
+typedef struct PgStat_MsgResetslrucounter
+{
+	PgStat_MsgHdr m_hdr;
+	int			m_index;
+} PgStat_MsgResetslrucounter;
+
+/* ----------
+ * PgStat_MsgResetreplslotcounter Sent by the backend to tell the collector
+ *								to reset replication slot counter(s)
+ * ----------
+ */
+typedef struct PgStat_MsgResetreplslotcounter
+{
+	PgStat_MsgHdr m_hdr;
+	NameData	m_slotname;
+	bool		clearall;
+} PgStat_MsgResetreplslotcounter;
+
+/* ----------
+ * PgStat_MsgAutovacStart		Sent by the autovacuum daemon to signal
+ *								that a database is going to be processed
+ * ----------
+ */
+typedef struct PgStat_MsgAutovacStart
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	TimestampTz m_start_time;
+} PgStat_MsgAutovacStart;
+
+
+/* ----------
+ * PgStat_MsgVacuum				Sent by the backend or autovacuum daemon
+ *								after VACUUM
+ * ----------
+ */
+typedef struct PgStat_MsgVacuum
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	Oid			m_tableoid;
+	bool		m_autovacuum;
+	TimestampTz m_vacuumtime;
+	PgStat_Counter m_live_tuples;
+	PgStat_Counter m_dead_tuples;
+} PgStat_MsgVacuum;
+
+
+/* ----------
+ * PgStat_MsgAnalyze			Sent by the backend or autovacuum daemon
+ *								after ANALYZE
+ * ----------
+ */
+typedef struct PgStat_MsgAnalyze
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	Oid			m_tableoid;
+	bool		m_autovacuum;
+	bool		m_resetcounter;
+	TimestampTz m_analyzetime;
+	PgStat_Counter m_live_tuples;
+	PgStat_Counter m_dead_tuples;
+} PgStat_MsgAnalyze;
+
+
+/* ----------
+ * PgStat_MsgArchiver			Sent by the archiver to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgArchiver
+{
+	PgStat_MsgHdr m_hdr;
+	bool		m_failed;		/* Failed attempt */
+	char		m_xlog[MAX_XFN_CHARS + 1];
+	TimestampTz m_timestamp;
+} PgStat_MsgArchiver;
+
+/* ----------
+ * PgStat_MsgBgWriter			Sent by the bgwriter to update statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgBgWriter
+{
+	PgStat_MsgHdr m_hdr;
+
+	PgStat_Counter m_timed_checkpoints;
+	PgStat_Counter m_requested_checkpoints;
+	PgStat_Counter m_buf_written_checkpoints;
+	PgStat_Counter m_buf_written_clean;
+	PgStat_Counter m_maxwritten_clean;
+	PgStat_Counter m_buf_written_backend;
+	PgStat_Counter m_buf_fsync_backend;
+	PgStat_Counter m_buf_alloc;
+	PgStat_Counter m_checkpoint_write_time; /* times in milliseconds */
+	PgStat_Counter m_checkpoint_sync_time;
+} PgStat_MsgBgWriter;
+
+/* ----------
+ * PgStat_MsgWal			Sent by backends and background processes to update WAL statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgWal
+{
+	PgStat_MsgHdr m_hdr;
+	PgStat_Counter m_wal_records;
+	PgStat_Counter m_wal_fpi;
+	uint64		m_wal_bytes;
+	PgStat_Counter m_wal_buffers_full;
+	PgStat_Counter m_wal_write;
+	PgStat_Counter m_wal_sync;
+	PgStat_Counter m_wal_write_time;	/* time spent writing wal records in
+										 * microseconds */
+	PgStat_Counter m_wal_sync_time; /* time spent syncing wal records in
+									 * microseconds */
+} PgStat_MsgWal;
+
+/* ----------
+ * PgStat_MsgSLRU			Sent by a backend to update SLRU statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgSLRU
+{
+	PgStat_MsgHdr m_hdr;
+	PgStat_Counter m_index;
+	PgStat_Counter m_blocks_zeroed;
+	PgStat_Counter m_blocks_hit;
+	PgStat_Counter m_blocks_read;
+	PgStat_Counter m_blocks_written;
+	PgStat_Counter m_blocks_exists;
+	PgStat_Counter m_flush;
+	PgStat_Counter m_truncate;
+} PgStat_MsgSLRU;
+
+/* ----------
+ * PgStat_MsgReplSlot	Sent by a backend or a wal sender to update replication
+ *						slot statistics.
+ * ----------
+ */
+typedef struct PgStat_MsgReplSlot
+{
+	PgStat_MsgHdr m_hdr;
+	NameData	m_slotname;
+	bool		m_create;
+	bool		m_drop;
+	PgStat_Counter m_spill_txns;
+	PgStat_Counter m_spill_count;
+	PgStat_Counter m_spill_bytes;
+	PgStat_Counter m_stream_txns;
+	PgStat_Counter m_stream_count;
+	PgStat_Counter m_stream_bytes;
+	PgStat_Counter m_total_txns;
+	PgStat_Counter m_total_bytes;
+} PgStat_MsgReplSlot;
+
+
+/* ----------
+ * PgStat_MsgRecoveryConflict	Sent by the backend upon recovery conflict
+ * ----------
+ */
+typedef struct PgStat_MsgRecoveryConflict
+{
+	PgStat_MsgHdr m_hdr;
+
+	Oid			m_databaseid;
+	int			m_reason;
+} PgStat_MsgRecoveryConflict;
+
+/* ----------
+ * PgStat_MsgTempFile	Sent by the backend upon creating a temp file
+ * ----------
+ */
+typedef struct PgStat_MsgTempFile
+{
+	PgStat_MsgHdr m_hdr;
+
+	Oid			m_databaseid;
+	size_t		m_filesize;
+} PgStat_MsgTempFile;
+
+/* ----------
+ * PgStat_FunctionCounts	The actual per-function counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_FunctionCounts
+{
+	PgStat_Counter f_numcalls;
+	instr_time	f_total_time;
+	instr_time	f_self_time;
+} PgStat_FunctionCounts;
+
+/* ----------
+ * PgStat_BackendFunctionEntry	Entry in backend's per-function hash table
+ * ----------
+ */
+typedef struct PgStat_BackendFunctionEntry
+{
+	Oid			f_id;
+	PgStat_FunctionCounts f_counts;
+} PgStat_BackendFunctionEntry;
+
+/* ----------
+ * PgStat_FunctionEntry			Per-function info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_FunctionEntry
+{
+	Oid			f_id;
+	PgStat_Counter f_numcalls;
+	PgStat_Counter f_total_time;	/* times in microseconds */
+	PgStat_Counter f_self_time;
+} PgStat_FunctionEntry;
+
+/* ----------
+ * PgStat_MsgFuncstat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_FUNCENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_FunctionEntry))
+
+typedef struct PgStat_MsgFuncstat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_FunctionEntry m_entry[PGSTAT_NUM_FUNCENTRIES];
+} PgStat_MsgFuncstat;
+
+/* ----------
+ * PgStat_MsgFuncpurge			Sent by the backend to tell the collector
+ *								about dead functions.
+ * ----------
+ */
+#define PGSTAT_NUM_FUNCPURGE  \
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(Oid))
+
+typedef struct PgStat_MsgFuncpurge
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	Oid			m_functionid[PGSTAT_NUM_FUNCPURGE];
+} PgStat_MsgFuncpurge;
+
+/* ----------
+ * PgStat_MsgDeadlock			Sent by the backend to tell the collector
+ *								about a deadlock that occurred.
+ * ----------
+ */
+typedef struct PgStat_MsgDeadlock
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+} PgStat_MsgDeadlock;
+
+/* ----------
+ * PgStat_MsgChecksumFailure	Sent by the backend to tell the collector
+ *								about checksum failures noticed.
+ * ----------
+ */
+typedef struct PgStat_MsgChecksumFailure
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_failurecount;
+	TimestampTz m_failure_time;
+} PgStat_MsgChecksumFailure;
+
+/* ----------
+ * PgStat_MsgConnect			Sent by the backend upon connection
+ *								establishment
+ * ----------
+ */
+typedef struct PgStat_MsgConnect
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+} PgStat_MsgConnect;
+
+/* ----------
+ * PgStat_MsgDisconnect			Sent by the backend when disconnecting
+ * ----------
+ */
+typedef struct PgStat_MsgDisconnect
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	SessionEndType m_cause;
+} PgStat_MsgDisconnect;
+
+/* ----------
+ * PgStat_Msg					Union over all possible messages.
+ * ----------
+ */
+typedef union PgStat_Msg
+{
+	PgStat_MsgHdr msg_hdr;
+	PgStat_MsgDummy msg_dummy;
+	PgStat_MsgInquiry msg_inquiry;
+	PgStat_MsgTabstat msg_tabstat;
+	PgStat_MsgTabpurge msg_tabpurge;
+	PgStat_MsgDropdb msg_dropdb;
+	PgStat_MsgResetcounter msg_resetcounter;
+	PgStat_MsgResetsharedcounter msg_resetsharedcounter;
+	PgStat_MsgResetsinglecounter msg_resetsinglecounter;
+	PgStat_MsgResetslrucounter msg_resetslrucounter;
+	PgStat_MsgResetreplslotcounter msg_resetreplslotcounter;
+	PgStat_MsgAutovacStart msg_autovacuum_start;
+	PgStat_MsgVacuum msg_vacuum;
+	PgStat_MsgAnalyze msg_analyze;
+	PgStat_MsgArchiver msg_archiver;
+	PgStat_MsgBgWriter msg_bgwriter;
+	PgStat_MsgWal msg_wal;
+	PgStat_MsgSLRU msg_slru;
+	PgStat_MsgFuncstat msg_funcstat;
+	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgRecoveryConflict msg_recoveryconflict;
+	PgStat_MsgDeadlock msg_deadlock;
+	PgStat_MsgTempFile msg_tempfile;
+	PgStat_MsgChecksumFailure msg_checksumfailure;
+	PgStat_MsgReplSlot msg_replslot;
+	PgStat_MsgConnect msg_connect;
+	PgStat_MsgDisconnect msg_disconnect;
+} PgStat_Msg;
+
+
+/* ------------------------------------------------------------
+ * Statistic collector data structures follow
+ *
+ * PGSTAT_FILE_FORMAT_ID should be changed whenever any of these
+ * data structures change.
+ * ------------------------------------------------------------
+ */
+
+#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA2
+
+/* ----------
+ * PgStat_StatDBEntry			The collector's data per database
+ * ----------
+ */
+typedef struct PgStat_StatDBEntry
+{
+	Oid			databaseid;
+	PgStat_Counter n_xact_commit;
+	PgStat_Counter n_xact_rollback;
+	PgStat_Counter n_blocks_fetched;
+	PgStat_Counter n_blocks_hit;
+	PgStat_Counter n_tuples_returned;
+	PgStat_Counter n_tuples_fetched;
+	PgStat_Counter n_tuples_inserted;
+	PgStat_Counter n_tuples_updated;
+	PgStat_Counter n_tuples_deleted;
+	TimestampTz last_autovac_time;
+	PgStat_Counter n_conflict_tablespace;
+	PgStat_Counter n_conflict_lock;
+	PgStat_Counter n_conflict_snapshot;
+	PgStat_Counter n_conflict_bufferpin;
+	PgStat_Counter n_conflict_startup_deadlock;
+	PgStat_Counter n_temp_files;
+	PgStat_Counter n_temp_bytes;
+	PgStat_Counter n_deadlocks;
+	PgStat_Counter n_checksum_failures;
+	TimestampTz last_checksum_failure;
+	PgStat_Counter n_block_read_time;	/* times in microseconds */
+	PgStat_Counter n_block_write_time;
+	PgStat_Counter n_sessions;
+	PgStat_Counter total_session_time;
+	PgStat_Counter total_active_time;
+	PgStat_Counter total_idle_in_xact_time;
+	PgStat_Counter n_sessions_abandoned;
+	PgStat_Counter n_sessions_fatal;
+	PgStat_Counter n_sessions_killed;
+
+	TimestampTz stat_reset_timestamp;
+	TimestampTz stats_timestamp;	/* time of db stats file update */
+
+	/*
+	 * tables and functions must be last in the struct, because we don't write
+	 * the pointers out to the stats file.
+	 */
+	HTAB	   *tables;
+	HTAB	   *functions;
+} PgStat_StatDBEntry;
+
+
+/* ----------
+ * PgStat_StatTabEntry			The collector's data per table (or index)
+ * ----------
+ */
+typedef struct PgStat_StatTabEntry
+{
+	Oid			tableid;
+
+	PgStat_Counter numscans;
+
+	PgStat_Counter tuples_returned;
+	PgStat_Counter tuples_fetched;
+
+	PgStat_Counter tuples_inserted;
+	PgStat_Counter tuples_updated;
+	PgStat_Counter tuples_deleted;
+	PgStat_Counter tuples_hot_updated;
+
+	PgStat_Counter n_live_tuples;
+	PgStat_Counter n_dead_tuples;
+	PgStat_Counter changes_since_analyze;
+	PgStat_Counter unused_counter;	/* kept for ABI compatibility */
+	PgStat_Counter inserts_since_vacuum;
+
+	PgStat_Counter blocks_fetched;
+	PgStat_Counter blocks_hit;
+
+	TimestampTz vacuum_timestamp;	/* user initiated vacuum */
+	PgStat_Counter vacuum_count;
+	TimestampTz autovac_vacuum_timestamp;	/* autovacuum initiated */
+	PgStat_Counter autovac_vacuum_count;
+	TimestampTz analyze_timestamp;	/* user initiated */
+	PgStat_Counter analyze_count;
+	TimestampTz autovac_analyze_timestamp;	/* autovacuum initiated */
+	PgStat_Counter autovac_analyze_count;
+} PgStat_StatTabEntry;
+
+
+/* ----------
+ * PgStat_StatFuncEntry			The collector's data per function
+ * ----------
+ */
+typedef struct PgStat_StatFuncEntry
+{
+	Oid			functionid;
+
+	PgStat_Counter f_numcalls;
+
+	PgStat_Counter f_total_time;	/* times in microseconds */
+	PgStat_Counter f_self_time;
+} PgStat_StatFuncEntry;
+
+
+/*
+ * Archiver statistics kept in the stats collector
+ */
+typedef struct PgStat_ArchiverStats
+{
+	PgStat_Counter archived_count;	/* archival successes */
+	char		last_archived_wal[MAX_XFN_CHARS + 1];	/* last WAL file
+														 * archived */
+	TimestampTz last_archived_timestamp;	/* last archival success time */
+	PgStat_Counter failed_count;	/* failed archival attempts */
+	char		last_failed_wal[MAX_XFN_CHARS + 1]; /* WAL file involved in
+													 * last failure */
+	TimestampTz last_failed_timestamp;	/* last archival failure time */
+	TimestampTz stat_reset_timestamp;
+} PgStat_ArchiverStats;
+
+/*
+ * Global statistics kept in the stats collector
+ */
+typedef struct PgStat_GlobalStats
+{
+	TimestampTz stats_timestamp;	/* time of stats file update */
+	PgStat_Counter timed_checkpoints;
+	PgStat_Counter requested_checkpoints;
+	PgStat_Counter checkpoint_write_time;	/* times in milliseconds */
+	PgStat_Counter checkpoint_sync_time;
+	PgStat_Counter buf_written_checkpoints;
+	PgStat_Counter buf_written_clean;
+	PgStat_Counter maxwritten_clean;
+	PgStat_Counter buf_written_backend;
+	PgStat_Counter buf_fsync_backend;
+	PgStat_Counter buf_alloc;
+	TimestampTz stat_reset_timestamp;
+} PgStat_GlobalStats;
+
+/*
+ * WAL statistics kept in the stats collector
+ */
+typedef struct PgStat_WalStats
+{
+	PgStat_Counter wal_records;
+	PgStat_Counter wal_fpi;
+	uint64		wal_bytes;
+	PgStat_Counter wal_buffers_full;
+	PgStat_Counter wal_write;
+	PgStat_Counter wal_sync;
+	PgStat_Counter wal_write_time;
+	PgStat_Counter wal_sync_time;
+	TimestampTz stat_reset_timestamp;
+} PgStat_WalStats;
+
+/*
+ * SLRU statistics kept in the stats collector
+ */
+typedef struct PgStat_SLRUStats
+{
+	PgStat_Counter blocks_zeroed;
+	PgStat_Counter blocks_hit;
+	PgStat_Counter blocks_read;
+	PgStat_Counter blocks_written;
+	PgStat_Counter blocks_exists;
+	PgStat_Counter flush;
+	PgStat_Counter truncate;
+	TimestampTz stat_reset_timestamp;
+} PgStat_SLRUStats;
+
+/*
+ * Replication slot statistics kept in the stats collector
+ */
+typedef struct PgStat_StatReplSlotEntry
+{
+	NameData	slotname;
+	PgStat_Counter spill_txns;
+	PgStat_Counter spill_count;
+	PgStat_Counter spill_bytes;
+	PgStat_Counter stream_txns;
+	PgStat_Counter stream_count;
+	PgStat_Counter stream_bytes;
+	PgStat_Counter total_txns;
+	PgStat_Counter total_bytes;
+	TimestampTz stat_reset_timestamp;
+} PgStat_StatReplSlotEntry;
+
+
+/*
+ * Working state needed to accumulate per-function-call timing statistics.
+ */
+typedef struct PgStat_FunctionCallUsage
+{
+	/* Link to function's hashtable entry (must still be there at exit!) */
+	/* NULL means we are not tracking the current function call */
+	PgStat_FunctionCounts *fs;
+	/* Total time previously charged to function, as of function start */
+	instr_time	save_f_total_time;
+	/* Backend-wide total time as of function start */
+	instr_time	save_total;
+	/* system clock as of function start */
+	instr_time	f_start;
+} PgStat_FunctionCallUsage;
+
+
+/* ----------
+ * GUC parameters
+ * ----------
+ */
+extern PGDLLIMPORT bool pgstat_track_counts;
+extern PGDLLIMPORT int pgstat_track_functions;
+extern char *pgstat_stat_directory;
+extern char *pgstat_stat_tmpname;
+extern char *pgstat_stat_filename;
+
+/*
+ * BgWriter statistics counters are updated directly by bgwriter and bufmgr
+ */
+extern PgStat_MsgBgWriter BgWriterStats;
+
+/*
+ * WAL statistics counter is updated by backends and background processes
+ */
+extern PgStat_MsgWal WalStats;
+
+/*
+ * Updated by pgstat_count_buffer_*_time macros
+ */
+extern PgStat_Counter pgStatBlockReadTime;
+extern PgStat_Counter pgStatBlockWriteTime;
+
+/*
+ * Updated by pgstat_count_conn_*_time macros, called by
+ * pgstat_report_activity().
+ */
+extern PgStat_Counter pgStatActiveTime;
+extern PgStat_Counter pgStatTransactionIdleTime;
+
+
+/*
+ * Updated by the traffic cop and in errfinish()
+ */
+extern SessionEndType pgStatSessionEndCause;
+
+/* ----------
+ * Functions called from postmaster
+ * ----------
+ */
+extern void pgstat_init(void);
+extern int	pgstat_start(void);
+extern void pgstat_reset_all(void);
+extern void allow_immediate_pgstat_restart(void);
+
+#ifdef EXEC_BACKEND
+extern void PgstatCollectorMain(int argc, char *argv[]) pg_attribute_noreturn();
+#endif
+
+
+/* ----------
+ * Functions called from backends
+ * ----------
+ */
+extern void pgstat_ping(void);
+
+extern void pgstat_report_stat(bool force);
+extern void pgstat_vacuum_stat(void);
+extern void pgstat_drop_database(Oid databaseid);
+
+extern void pgstat_clear_snapshot(void);
+extern void pgstat_reset_counters(void);
+extern void pgstat_reset_shared_counters(const char *);
+extern void pgstat_reset_single_counter(Oid objectid, PgStat_Single_Reset_Type type);
+extern void pgstat_reset_slru_counter(const char *);
+extern void pgstat_reset_replslot_counter(const char *name);
+
+extern void pgstat_report_connect(Oid dboid);
+extern void pgstat_report_autovac(Oid dboid);
+extern void pgstat_report_vacuum(Oid tableoid, bool shared,
+								 PgStat_Counter livetuples, PgStat_Counter deadtuples);
+extern void pgstat_report_analyze(Relation rel,
+								  PgStat_Counter livetuples, PgStat_Counter deadtuples,
+								  bool resetcounter);
+
+extern void pgstat_report_recovery_conflict(int reason);
+extern void pgstat_report_deadlock(void);
+extern void pgstat_report_checksum_failures_in_db(Oid dboid, int failurecount);
+extern void pgstat_report_checksum_failure(void);
+extern void pgstat_report_replslot(const PgStat_StatReplSlotEntry *repSlotStat);
+extern void pgstat_report_replslot_create(const char *slotname);
+extern void pgstat_report_replslot_drop(const char *slotname);
+
+extern void pgstat_initialize(void);
+
+
+extern PgStat_TableStatus *find_tabstat_entry(Oid rel_id);
+extern PgStat_BackendFunctionEntry *find_funcstat_entry(Oid func_id);
+
+extern void pgstat_initstats(Relation rel);
+
+/* nontransactional event counts are simple enough to inline */
+
+#define pgstat_count_heap_scan(rel)									\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_numscans++;				\
+	} while (0)
+#define pgstat_count_heap_getnext(rel)								\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_tuples_returned++;		\
+	} while (0)
+#define pgstat_count_heap_fetch(rel)								\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_tuples_fetched++;		\
+	} while (0)
+#define pgstat_count_index_scan(rel)								\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_numscans++;				\
+	} while (0)
+#define pgstat_count_index_tuples(rel, n)							\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_tuples_returned += (n);	\
+	} while (0)
+#define pgstat_count_buffer_read(rel)								\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_blocks_fetched++;		\
+	} while (0)
+#define pgstat_count_buffer_hit(rel)								\
+	do {															\
+		if ((rel)->pgstat_info != NULL)								\
+			(rel)->pgstat_info->t_counts.t_blocks_hit++;			\
+	} while (0)
+#define pgstat_count_buffer_read_time(n)							\
+	(pgStatBlockReadTime += (n))
+#define pgstat_count_buffer_write_time(n)							\
+	(pgStatBlockWriteTime += (n))
+#define pgstat_count_conn_active_time(n)							\
+	(pgStatActiveTime += (n))
+#define pgstat_count_conn_txn_idle_time(n)							\
+	(pgStatTransactionIdleTime += (n))
+
+extern void pgstat_count_heap_insert(Relation rel, PgStat_Counter n);
+extern void pgstat_count_heap_update(Relation rel, bool hot);
+extern void pgstat_count_heap_delete(Relation rel);
+extern void pgstat_count_truncate(Relation rel);
+extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
+
+struct FunctionCallInfoBaseData;
+extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
+									   PgStat_FunctionCallUsage *fcu);
+extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
+									  bool finalize);
+
+extern void AtEOXact_PgStat(bool isCommit, bool parallel);
+extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
+
+extern void AtPrepare_PgStat(void);
+extern void PostPrepare_PgStat(void);
+
+extern void pgstat_twophase_postcommit(TransactionId xid, uint16 info,
+									   void *recdata, uint32 len);
+extern void pgstat_twophase_postabort(TransactionId xid, uint16 info,
+									  void *recdata, uint32 len);
+
+extern void pgstat_send_archiver(const char *xlog, bool failed);
+extern void pgstat_send_bgwriter(void);
+extern void pgstat_send_wal(bool force);
+
+/* ----------
+ * Support functions for the SQL-callable functions to
+ * generate the pgstat* views.
+ * ----------
+ */
+extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
+extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
+extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
+extern PgStat_GlobalStats *pgstat_fetch_global(void);
+extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
+extern PgStat_SLRUStats *pgstat_fetch_slru(void);
+extern PgStat_StatReplSlotEntry *pgstat_fetch_replslot(NameData slotname);
+
+extern void pgstat_count_slru_page_zeroed(int slru_idx);
+extern void pgstat_count_slru_page_hit(int slru_idx);
+extern void pgstat_count_slru_page_read(int slru_idx);
+extern void pgstat_count_slru_page_written(int slru_idx);
+extern void pgstat_count_slru_page_exists(int slru_idx);
+extern void pgstat_count_slru_flush(int slru_idx);
+extern void pgstat_count_slru_truncate(int slru_idx);
+extern const char *pgstat_slru_name(int slru_idx);
+extern int	pgstat_slru_index(const char *name);
+
+#endif							/* PGSTAT_H */