The new files for statistical system views.

Jan

src/backend/utils/adt/pgstatfuncs.c

+#include "postgres.h"
+#include "fmgr.h"
+
+#include "utils/hsearch.h"
+#include "access/xact.h"
+#include "catalog/pg_shadow.h"
+#include "nodes/execnodes.h"
+
+#include "pgstat.h"
+
+extern Datum	pg_stat_get_numscans(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_tuples_returned(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_tuples_fetched(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_tuples_inserted(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_tuples_updated(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_tuples_deleted(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_blocks_hit(PG_FUNCTION_ARGS);
+
+extern Datum	pg_stat_get_backend_idset(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_backend_pid(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_backend_dbid(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_backend_userid(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_backend_activity(PG_FUNCTION_ARGS);
+
+extern Datum	pg_stat_get_db_numbackends(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_db_xact_commit(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_db_xact_rollback(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_db_blocks_fetched(PG_FUNCTION_ARGS);
+extern Datum	pg_stat_get_db_blocks_hit(PG_FUNCTION_ARGS);
+
+
+Datum
+pg_stat_get_numscans(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->numscans);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_returned(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->tuples_returned);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_fetched(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->tuples_fetched);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_inserted(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->tuples_inserted);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_updated(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->tuples_updated);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_tuples_deleted(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->tuples_deleted);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->blocks_fetched);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_blocks_hit(PG_FUNCTION_ARGS)
+{
+	PgStat_StatTabEntry	   *tabentry;
+	Oid						relid;
+	int64					result;
+
+	relid  = PG_GETARG_OID(0);
+
+	if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(tabentry->blocks_hit);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
+{
+	FmgrInfo	   *fmgr_info = fcinfo->flinfo;
+	MemoryContext	oldcxt;
+	int32			result;
+
+	if (fcinfo->resultinfo == NULL)
+		elog(ERROR, "called in context that does not accept a set result (1)");
+	if (!IsA(fcinfo->resultinfo, ReturnSetInfo))
+		elog(ERROR, "called in context that does not accept a set result (2)");
+
+	if (fmgr_info->fn_extra == NULL)
+	{
+		if (fmgr_info->fn_mcxt == NULL)
+			elog(ERROR, "No function memory context in set-function");
+
+		oldcxt = MemoryContextSwitchTo(fmgr_info->fn_mcxt);
+		fmgr_info->fn_extra = palloc(sizeof(int32) * 2);
+		((int32 *)(fmgr_info->fn_extra))[0] = 0;
+		((int32 *)(fmgr_info->fn_extra))[1] = 
+						(int32)pgstat_fetch_stat_numbackends();
+		MemoryContextSwitchTo(oldcxt);
+	}
+
+	((int32 *)(fmgr_info->fn_extra))[0] += 1;
+	result = ((int32 *)(fmgr_info->fn_extra))[0];
+
+
+	if (result > ((int32 *)(fmgr_info->fn_extra))[1])
+	{
+		((ReturnSetInfo *)(fcinfo->resultinfo))->isDone = ExprEndResult;
+		PG_RETURN_NULL();
+	}
+
+	((ReturnSetInfo *)(fcinfo->resultinfo))->isDone = ExprMultipleResult;
+	PG_RETURN_INT32(result);
+}
+
+
+Datum
+pg_stat_get_backend_pid(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry	   *beentry;
+	int32					beid;
+
+	beid  = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT32(beentry->procpid);
+}
+
+
+Datum
+pg_stat_get_backend_dbid(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry	   *beentry;
+	int32					beid;
+
+	beid  = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	PG_RETURN_OID(beentry->databaseid);
+}
+
+
+Datum
+pg_stat_get_backend_userid(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry	   *beentry;
+	int32					beid;
+
+	beid  = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	PG_RETURN_OID(beentry->userid);
+}
+
+
+Datum
+pg_stat_get_backend_activity(PG_FUNCTION_ARGS)
+{
+	PgStat_StatBeEntry	   *beentry;
+	int32					beid;
+	int						len;
+	text				   *result;
+
+	if (!superuser())
+		PG_RETURN_NULL();
+
+	beid  = PG_GETARG_INT32(0);
+
+	if ((beentry = pgstat_fetch_stat_beentry(beid)) == NULL)
+		PG_RETURN_NULL();
+
+	len = strlen(beentry->activity);
+	result = palloc(VARHDRSZ + len);
+	VARATT_SIZEP(result) = VARHDRSZ + len;
+	memcpy(VARDATA(result), beentry->activity, len);
+
+	PG_RETURN_TEXT_P(result);
+}
+
+
+Datum
+pg_stat_get_db_numbackends(PG_FUNCTION_ARGS)
+{
+	PgStat_StatDBEntry	   *dbentry;
+	Oid						dbid;
+	int32					result;
+
+	dbid  = PG_GETARG_OID(0);
+
+	if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+		result = 0;
+	else
+		result = (int32)(dbentry->n_backends);
+
+	PG_RETURN_INT32(result);
+}
+
+
+Datum
+pg_stat_get_db_xact_commit(PG_FUNCTION_ARGS)
+{
+	PgStat_StatDBEntry	   *dbentry;
+	Oid						dbid;
+	int64					result;
+
+	dbid  = PG_GETARG_OID(0);
+
+	if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(dbentry->n_xact_commit);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_db_xact_rollback(PG_FUNCTION_ARGS)
+{
+	PgStat_StatDBEntry	   *dbentry;
+	Oid						dbid;
+	int64					result;
+
+	dbid  = PG_GETARG_OID(0);
+
+	if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(dbentry->n_xact_rollback);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_db_blocks_fetched(PG_FUNCTION_ARGS)
+{
+	PgStat_StatDBEntry	   *dbentry;
+	Oid						dbid;
+	int64					result;
+
+	dbid  = PG_GETARG_OID(0);
+
+	if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(dbentry->n_blocks_fetched);
+
+	PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_db_blocks_hit(PG_FUNCTION_ARGS)
+{
+	PgStat_StatDBEntry	   *dbentry;
+	Oid						dbid;
+	int64					result;
+
+	dbid  = PG_GETARG_OID(0);
+
+	if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+		result = 0;
+	else
+		result = (int64)(dbentry->n_blocks_hit);
+
+	PG_RETURN_INT64(result);
+}
+
+

src/include/pgstat.h

+/* ----------
+ *	pgstat.h
+ *
+ *	Definitions for the PostgreSQL statistics collector daemon.
+ *
+ *	Copyright (c) 2001, PostgreSQL Global Development Group
+ *
+ *  $Id: pgstat.h,v 1.1 2001/06/22 19:18:36 wieck Exp $
+ * ----------
+ */
+#ifndef PGSTAT_H
+#define PGSTAT_H
+
+/* ----------
+ * Paths for the statistics files. The %s is replaced with the
+ * installations $PGDATA.
+ * ----------
+ */
+#define	PGSTAT_STAT_FILENAME	"%s/pgstat.stat"
+#define	PGSTAT_STAT_TMPFILE		"%s/pgstat.tmp.%d"
+
+/* ----------
+ * Timer definitions.
+ * ----------
+ */
+#define PGSTAT_STAT_INTERVAL	500		/* How often to write the status	*/
+										/* file in milliseconds.			*/
+
+#define PGSTAT_DESTROY_DELAY	10000	/* How long to keep destroyed		*/
+										/* objects known to give delayed	*/
+										/* UDP packets time to arrive		*/
+										/* in milliseconds.					*/
+
+#define PGSTAT_DESTROY_COUNT	(PGSTAT_DESTROY_DELAY 					\
+								/ PGSTAT_STAT_INTERVAL)
+
+
+/* ----------
+ * How much of the actual query to send to the collector.
+ * ----------
+ */
+#define PGSTAT_ACTIVITY_SIZE	256
+
+
+/* ----------
+ * The types of backend/postmaster -> collector messages
+ * ----------
+ */
+#define	PGSTAT_MTYPE_DUMMY			0
+#define	PGSTAT_MTYPE_BESTART		1
+#define	PGSTAT_MTYPE_BETERM			2
+#define	PGSTAT_MTYPE_ACTIVITY		3
+#define	PGSTAT_MTYPE_TABSTAT		4
+#define	PGSTAT_MTYPE_TABPURGE		5
+#define	PGSTAT_MTYPE_DROPDB			6
+#define	PGSTAT_MTYPE_RESETCOUNTER	7
+
+/* ----------
+ * TODO
+ * For simplicity now, the number of messages buffered in
+ * pgstat_recvbuffer(). Should be an amount of bytes used
+ * for a gapless wraparound buffer.
+ * ----------
+ */
+#define	PGSTAT_RECVBUFFERSZ		1024
+
+
+/* ----------
+ * The initial size hints for the hash tables used in the
+ * collector.
+ * ----------
+ */
+#define PGSTAT_DB_HASH_SIZE		16
+#define PGSTAT_BE_HASH_SIZE		512
+#define PGSTAT_TAB_HASH_SIZE	512
+
+
+/* ----------
+ * The data type used for counters.
+ * ----------
+ */
+typedef int64	PgStat_Counter;
+
+
+/* ------------------------------------------------------------
+ * Statistic collector data structures follow
+ * ------------------------------------------------------------
+ */
+/* ----------
+ * PgStat_StatDBEntry			The collectors data per database
+ * ----------
+ */
+typedef struct	PgStat_StatDBEntry
+{
+	Oid				databaseid;
+	HTAB		   *tables;
+	int				n_backends;
+	PgStat_Counter	n_connects;
+	PgStat_Counter	n_xact_commit;
+	PgStat_Counter	n_xact_rollback;
+	PgStat_Counter	n_blocks_fetched;
+	PgStat_Counter	n_blocks_hit;
+	int				destroy;			
+} PgStat_StatDBEntry;
+
+
+/* ----------
+ * PgStat_StatBeEntry			The collectors data per backend
+ * ----------
+ */
+typedef struct	PgStat_StatBeEntry
+{
+	Oid				databaseid;
+	Oid				userid;
+	int				procpid;
+	char			activity[PGSTAT_ACTIVITY_SIZE];
+} PgStat_StatBeEntry;
+
+
+/* ----------
+ * PgStat_StatBeDead			Because UDP packets can arrive out of
+ *								order, we need to keep some information
+ *								about backends that are known to be
+ *								dead for some seconds. This info is held
+ *								in a hash table of these structs.
+ * ----------
+ */
+typedef struct	PgStat_StatBeDead
+{
+	int				procpid;
+	int				backendid;
+	int				destroy;
+} PgStat_StatBeDead;
+
+
+/* ----------
+ * PgStat_StatTabEntry			The collectors data table data
+ * ----------
+ */
+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		blocks_fetched;
+	PgStat_Counter		blocks_hit;
+
+	int					destroy;
+} PgStat_StatTabEntry;
+
+
+/* ------------------------------------------------------------
+ * Message formats follow
+ * ------------------------------------------------------------
+ */
+
+
+/* ----------
+ * PgStat_MsgHdr				The common message header
+ * ----------
+ */
+typedef struct	PgStat_MsgHdr
+{
+	int						m_type;
+	int						m_size;
+	int						m_backendid;
+	int						m_procpid;
+	Oid						m_databaseid;
+	Oid						m_userid;
+} PgStat_MsgHdr;
+
+/* ----------
+ * PgStat_TabEntry				A table slot in a MsgTabstat
+ * ----------
+ */
+typedef struct	PgStat_TableEntry
+{
+	Oid						t_id;
+
+	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_blocks_fetched;
+	PgStat_Counter			t_blocks_hit;
+} PgStat_TableEntry;
+
+
+/* ----------
+ * PgStat_MsgDummy				A dummy message, ignored by the collector
+ * ----------
+ */
+typedef struct	PgStat_MsgDummy
+{
+	PgStat_MsgHdr			m_hdr;
+	char					m_dummy[512];
+} PgStat_MsgDummy;
+
+/* ----------
+ * PgStat_MsgBestart			Sent by the backend on startup
+ * ----------
+ */
+typedef struct	PgStat_MsgBestart
+{
+	PgStat_MsgHdr			m_hdr;
+} PgStat_MsgBestart;
+
+/* ----------
+ * PgStat_MsgBeterm				Sent by the postmaster after backend exit
+ * ----------
+ */
+typedef struct	PgStat_MsgBeterm
+{
+	PgStat_MsgHdr			m_hdr;
+} PgStat_MsgBeterm;
+
+/* ----------
+ * PgStat_MsgActivity			Sent by the backends when they start
+ *								to parse a query.
+ * ----------
+ */
+typedef struct	PgStat_MsgActivity
+{
+	PgStat_MsgHdr			m_hdr;
+	char					m_what[PGSTAT_ACTIVITY_SIZE];
+} PgStat_MsgActivity;
+
+/* ----------
+ * How many table entries fit into a MsgTabstat. Actually,
+ * this will keep the UDP packets below 1K, what should fit
+ * unfragmented into the MTU of the lo interface on most
+ * platforms. Does anybody care for platforms where it doesn't?
+ * ----------
+ */
+#define PGSTAT_NUM_TABENTRIES	((1000 - sizeof(PgStat_MsgHdr))			\
+								/ sizeof(PgStat_TableEntry))
+
+/* ----------
+ * PgStat_MsgTabstat			Sent by the backend to report table
+ *								and buffer access statistics.
+ * ----------
+ */
+typedef struct	PgStat_MsgTabstat
+{
+	PgStat_MsgHdr			m_hdr;
+	int						m_nentries;
+	int						m_xact_commit;
+	int						m_xact_rollback;
+	PgStat_TableEntry		m_entry[PGSTAT_NUM_TABENTRIES];
+} PgStat_MsgTabstat;
+
+
+/* ----------
+ * How many Oid entries fit into a MsgTabpurge.
+ * ----------
+ */
+#define PGSTAT_NUM_TABPURGE		((1000 - sizeof(PgStat_MsgHdr))			\
+								/ sizeof(PgStat_TableEntry))
+
+/* ----------
+ * PgStat_MsgTabpurge			Sent by the backend to tell the collector
+ *								about dead tables.
+ * ----------
+ */
+typedef struct	PgStat_MsgTabpurge
+{
+	PgStat_MsgHdr			m_hdr;
+	int						m_nentries;
+	Oid						m_tableid[PGSTAT_NUM_TABPURGE];
+} PgStat_MsgTabpurge;
+
+
+/* ----------
+ * PgStat_MsgDropdb				Sent by the backend to tell the collector
+ *								about 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;
+} PgStat_MsgResetcounter;
+
+
+/* ----------
+ * PgStat_Msg					Union over all possible messages.
+ * ----------
+ */
+typedef union	PgStat_Msg
+{
+	PgStat_MsgHdr			msg_hdr;
+	PgStat_MsgDummy			msg_dummy;
+	PgStat_MsgBestart		msg_bestart;
+	PgStat_MsgActivity		msg_activity;
+	PgStat_MsgTabstat		msg_tabstat;
+	PgStat_MsgTabpurge		msg_tabpurge;
+	PgStat_MsgDropdb		msg_dropdb;
+	PgStat_MsgResetcounter	msg_resetcounter;
+} PgStat_Msg;
+
+
+
+
+/* ----------
+ * Functions called from postmaster
+ * ----------
+ */
+extern int		pgstat_init(void);
+extern int		pgstat_start(void);
+extern int		pgstat_ispgstat(int pid);
+extern void		pgstat_beterm(int pid);
+
+/* ----------
+ * Functions called from backends
+ * ----------
+ */
+extern void		pgstat_bestart(void);
+
+extern void		pgstat_ping(void);
+extern void		pgstat_report_activity(char *what);
+extern void		pgstat_report_tabstat(void);
+extern int		pgstat_vacuum_tabstat(void);
+
+extern void		pgstat_reset_counters(void);
+
+extern void		pgstat_initstats(PgStat_Info *stats, Relation rel);
+
+extern void		pgstat_reset_heap_scan(PgStat_Info *stats);
+extern void		pgstat_count_heap_scan(PgStat_Info *stats);
+extern void		pgstat_count_heap_getnext(PgStat_Info *stats);
+extern void		pgstat_count_heap_fetch(PgStat_Info *stats);
+extern void		pgstat_count_heap_insert(PgStat_Info *stats);
+extern void		pgstat_count_heap_update(PgStat_Info *stats);
+extern void		pgstat_count_heap_delete(PgStat_Info *stats);
+
+extern void		pgstat_reset_index_scan(PgStat_Info *stats);
+extern void		pgstat_count_index_scan(PgStat_Info *stats);
+extern void		pgstat_count_index_getnext(PgStat_Info *stats);
+
+extern void		pgstat_count_buffer_read(PgStat_Info *stats,
+											Relation rel);
+extern void		pgstat_count_buffer_hit(PgStat_Info *stats,
+											Relation rel);
+extern void		pgstat_count_xact_commit(void);
+extern void		pgstat_count_xact_rollback(void);
+
+/* ----------
+ * 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_StatBeEntry  *pgstat_fetch_stat_beentry(int beid);
+extern int					pgstat_fetch_stat_numbackends(void);
+
+
+#endif /* PGSTAT_H */