diff --git a/contrib/pg_stat_statements/Makefile b/contrib/pg_stat_statements/Makefile
index 081f997d70..3ec627b956 100644
--- a/contrib/pg_stat_statements/Makefile
+++ b/contrib/pg_stat_statements/Makefile
@@ -6,7 +6,7 @@ OBJS = \
pg_stat_statements.o
EXTENSION = pg_stat_statements
-DATA = pg_stat_statements--1.4.sql \
+DATA = pg_stat_statements--1.4.sql pg_stat_statements--1.8--1.9.sql \
pg_stat_statements--1.7--1.8.sql pg_stat_statements--1.6--1.7.sql \
pg_stat_statements--1.5--1.6.sql pg_stat_statements--1.4--1.5.sql \
pg_stat_statements--1.3--1.4.sql pg_stat_statements--1.2--1.3.sql \
diff --git a/contrib/pg_stat_statements/expected/pg_stat_statements.out b/contrib/pg_stat_statements/expected/pg_stat_statements.out
index e0edb134f3..a1eaedca8e 100644
--- a/contrib/pg_stat_statements/expected/pg_stat_statements.out
+++ b/contrib/pg_stat_statements/expected/pg_stat_statements.out
@@ -859,4 +859,19 @@ SELECT query, plans, calls, rows FROM pg_stat_statements ORDER BY query COLLATE
SELECT query, plans, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C" | 1 | 0 | 0
(6 rows)
+--
+-- Checking the execution of the pg_stat_statements_info view
+--
+SELECT pg_stat_statements_reset(0,0,0);
+ pg_stat_statements_reset
+--------------------------
+
+(1 row)
+
+SELECT dealloc FROM pg_stat_statements_info;
+ dealloc
+---------
+ 0
+(1 row)
+
DROP EXTENSION pg_stat_statements;
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.8--1.9.sql b/contrib/pg_stat_statements/pg_stat_statements--1.8--1.9.sql
new file mode 100644
index 0000000000..4edbc03dc1
--- /dev/null
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.8--1.9.sql
@@ -0,0 +1,18 @@
+/* contrib/pg_stat_statements/pg_stat_statements--1.8--1.9.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.9'" to load this file. \quit
+
+--- Define pg_stat_statements_info
+CREATE FUNCTION pg_stat_statements_info (
+ OUT dealloc bigint,
+ OUT reset_exec_time TIMESTAMP WITH TIME ZONE
+)
+RETURNS record
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+CREATE VIEW pg_stat_statements_info AS
+ SELECT * FROM pg_stat_statements_info();
+
+GRANT SELECT ON pg_stat_statements_info TO PUBLIC;
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 1eac9edaee..0857c1e2a4 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -81,6 +81,7 @@
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
+#include "utils/timestamp.h"
PG_MODULE_MAGIC;
@@ -98,7 +99,7 @@ PG_MODULE_MAGIC;
#define PGSS_TEXT_FILE PG_STAT_TMP_DIR "/pgss_query_texts.stat"
/* Magic number identifying the stats file format */
-static const uint32 PGSS_FILE_HEADER = 0x20171004;
+static const uint32 PGSS_FILE_HEADER = 0x20201116;
/* PostgreSQL major version number, changes in which invalidate all entries */
static const uint32 PGSS_PG_MAJOR_VERSION = PG_VERSION_NUM / 100;
@@ -193,6 +194,17 @@ typedef struct Counters
uint64 wal_bytes; /* total amount of WAL bytes generated */
} Counters;
+/*
+ * Counter for pg_stat_statements_info
+ */
+typedef struct pgssInfoCounters
+{
+ int64 dealloc; /* # of deallocation */
+ TimestampTz reset_exec_time; /* timestamp with all stats reset */
+ bool reset_exec_time_isnull; /* if true last_dealloc is null */
+ slock_t mutex; /* protects the counters only */
+} pgssInfoCounters;
+
/*
* Statistics per statement
*
@@ -222,6 +234,7 @@ typedef struct pgssSharedState
Size extent; /* current extent of query file */
int n_writers; /* number of active writers to query file */
int gc_count; /* query file garbage collection cycle count */
+ pgssInfoCounters pgss_info; /* Counter for pg_stat_statements_info */
} pgssSharedState;
/*
@@ -327,6 +340,7 @@ PG_FUNCTION_INFO_V1(pg_stat_statements_1_2);
PG_FUNCTION_INFO_V1(pg_stat_statements_1_3);
PG_FUNCTION_INFO_V1(pg_stat_statements_1_8);
PG_FUNCTION_INFO_V1(pg_stat_statements);
+PG_FUNCTION_INFO_V1(pg_stat_statements_info);
static void pgss_shmem_startup(void);
static void pgss_shmem_shutdown(int code, Datum arg);
@@ -554,6 +568,9 @@ pgss_shmem_startup(void)
pgss->extent = 0;
pgss->n_writers = 0;
pgss->gc_count = 0;
+ pgss->pgss_info.dealloc = 0;
+ pgss->pgss_info.reset_exec_time = 0;
+ pgss->pgss_info.reset_exec_time_isnull = true;
}
memset(&info, 0, sizeof(info));
@@ -673,6 +690,10 @@ pgss_shmem_startup(void)
entry->counters = temp.counters;
}
+ /* Read pgss_info */
+ if (fread(&pgss->pgss_info, sizeof(pgssInfoCounters), 1, file) != 1)
+ goto read_error;
+
pfree(buffer);
FreeFile(file);
FreeFile(qfile);
@@ -794,6 +815,10 @@ pgss_shmem_shutdown(int code, Datum arg)
}
}
+ /* Dump pgss_info */
+ if (fwrite(&pgss->pgss_info, sizeof(pgssInfoCounters), 1, file) != 1)
+ goto error;
+
free(qbuffer);
qbuffer = NULL;
@@ -1490,6 +1515,7 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
#define PG_STAT_STATEMENTS_COLS_V1_3 23
#define PG_STAT_STATEMENTS_COLS_V1_8 32
#define PG_STAT_STATEMENTS_COLS 32 /* maximum of above */
+#define PG_STAT_STATEMENTS_INFO_COLS 2
/*
* Retrieve statement statistics.
@@ -1862,6 +1888,42 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
tuplestore_donestoring(tupstore);
}
+Datum
+pg_stat_statements_info(PG_FUNCTION_ARGS)
+{
+ TupleDesc tupdesc;
+ HeapTuple result_tuple;
+ Datum result;
+ Datum values[PG_STAT_STATEMENTS_INFO_COLS];
+ bool nulls[PG_STAT_STATEMENTS_INFO_COLS];
+ bool ts_isnull;
+ int i = 0;
+
+ Assert(PG_STAT_STATEMENTS_INFO_COLS == 2);
+
+ if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+ elog(ERROR, "return type must be a row type");
+
+ tupdesc = BlessTupleDesc(tupdesc);
+
+ memset(nulls, 0, sizeof(nulls));
+ {
+ volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
+ SpinLockAcquire(&s->mutex);
+ values[i++] = pgss->pgss_info.dealloc;
+ ts_isnull = pgss->pgss_info.reset_exec_time_isnull;
+ if (!ts_isnull)
+ values[i++] = pgss->pgss_info.reset_exec_time;
+ else
+ nulls[i++] = true;
+ SpinLockRelease(&s->mutex);
+ }
+ result_tuple = heap_form_tuple(tupdesc, values, nulls);
+ result = HeapTupleGetDatum(result_tuple);
+
+ return result;
+}
+
/*
* Estimate shared memory space needed.
*/
@@ -1902,7 +1964,18 @@ entry_alloc(pgssHashKey *key, Size query_offset, int query_len, int encoding,
/* Make space if needed */
while (hash_get_num_entries(pgss_hash) >= pgss_max)
+ {
entry_dealloc();
+ /* Update pgss_info */
+ {
+ volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
+ SpinLockAcquire(&s->mutex);
+ s->pgss_info.dealloc += 1; /* increment dealloc count */
+ SpinLockRelease(&s->mutex);
+ }
+ ereport(LOG,
+ (errmsg("The information in pg_stat_statements has been deallocated.")));
+ }
/* Find or create an entry with desired hash code */
entry = (pgssEntry *) hash_search(pgss_hash, key, HASH_ENTER, &found);
@@ -2458,6 +2531,9 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
long num_entries;
long num_remove = 0;
pgssHashKey key;
+ TimestampTz reset_ts;
+
+ reset_ts = GetCurrentTimestamp();
if (!pgss || !pgss_hash)
ereport(ERROR,
@@ -2503,6 +2579,16 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
num_remove++;
}
+
+ /* Reset and Update pgss_info */
+ {
+ volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
+ SpinLockAcquire(&s->mutex);
+ s->pgss_info.dealloc = 0; /* reset dealloc count */
+ s->pgss_info.reset_exec_time = reset_ts; /* reset execution time */
+ s->pgss_info.reset_exec_time_isnull = false;
+ SpinLockRelease(&s->mutex);
+ }
}
/* All entries are removed? */
diff --git a/contrib/pg_stat_statements/pg_stat_statements.control b/contrib/pg_stat_statements/pg_stat_statements.control
index 65b18b11d2..2f1ce6ed50 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.control
+++ b/contrib/pg_stat_statements/pg_stat_statements.control
@@ -1,5 +1,5 @@
# pg_stat_statements extension
comment = 'track planning and execution statistics of all SQL statements executed'
-default_version = '1.8'
+default_version = '1.9'
module_pathname = '$libdir/pg_stat_statements'
relocatable = true
diff --git a/contrib/pg_stat_statements/sql/pg_stat_statements.sql b/contrib/pg_stat_statements/sql/pg_stat_statements.sql
index 996a24a293..4016d19553 100644
--- a/contrib/pg_stat_statements/sql/pg_stat_statements.sql
+++ b/contrib/pg_stat_statements/sql/pg_stat_statements.sql
@@ -357,4 +357,10 @@ SELECT 42;
SELECT 42;
SELECT query, plans, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C";
+--
+-- Checking the execution of the pg_stat_statements_info view
+--
+SELECT pg_stat_statements_reset(0,0,0);
+SELECT dealloc FROM pg_stat_statements_info;
+
DROP EXTENSION pg_stat_statements;
diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml
index cf2d25b7b2..21f150aabb 100644
--- a/doc/src/sgml/pgstatstatements.sgml
+++ b/doc/src/sgml/pgstatstatements.sgml
@@ -23,7 +23,8 @@
When pg_stat_statements is loaded, it tracks
statistics across all databases of the server. To access and manipulate
- these statistics, the module provides a view, pg_stat_statements,
+ these statistics, the module provides views, pg_stat_statements
+ and pg_stat_statements_info,
and the utility functions pg_stat_statements_reset and
pg_stat_statements. These are not available globally but
can be enabled for a specific database with
@@ -480,6 +481,55 @@
+
+ The <structname>pg_stat_statements_info</structname> View
+
+
+ This module tracks statistics of pg_stat_statements
+ itself for detailed performance analysis.
+ The statistics of pg_stat_statements itself are made available via a
+ view named pg_stat_statements_info.
+ This view contains only a single row.
+ The columns of the view are shown in .
+
+
+
+ <structname>pg_stat_statements_info</structname> Columns
+
+
+
+
+ Column Type
+
+
+ Description
+
+
+
+
+
+
+
+ dealloc bigint
+
+
+ Total number of deallocations of pg_stat_statements view entry
+
+
+
+
+
+ reset_exec_time timestamp with time zone
+
+
+ Shows the time at which pg_stat_statements_reset(0,0,0) was last called.
+
+
+
+
+
+
+
Functions