pg_stat_statements.o

EXTENSION = pg_stat_statements

DATA = pg_stat_statements--1.4.sql\

DATA = pg_stat_statements--1.4.sqlpg_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\

SELECT query, plans, calls, rows FROM pg_stat_statements ORDER BY query COLLATE "C" | 1 | 0 | 0

(6 rows)

--

-- access to pg_stat_statements_info view

--

SELECT pg_stat_statements_reset();

pg_stat_statements_reset

--------------------------

(1 row)

SELECT dealloc FROM pg_stat_statements_info;

dealloc

---------

0

(1 row)

DROP EXTENSION pg_stat_statements;

\echo Use"ALTER EXTENSION pg_stat_statements UPDATE TO '1.9'" to load this file. \quit

CREATEFUNCTIONpg_stat_statements_info(

OUT deallocbigint

)

RETURNSbigint

LANGUAGE C STRICT VOLATILE PARALLEL SAFE;

SELECT*FROM pg_stat_statements_info();

GRANTSELECTON pg_stat_statements_info TO PUBLIC;

#definePGSS_TEXT_FILEPG_STAT_TMP_DIR "/pgss_query_texts.stat"

staticconstuint32PGSS_FILE_HEADER=0x20171004;

staticconstuint32PGSS_FILE_HEADER=0x20201126;

staticconstuint32PGSS_PG_MAJOR_VERSION=PG_VERSION_NUM /100;

uint64wal_bytes;/* total amount of WAL bytes generated */

}Counters;

{

int64dealloc;/* # of times entries were deallocated */

}pgssGlobalStats;

Sizeextent;/* current extent of query file */

intn_writers;/* number of active writers to query file */

intgc_count;/* query file garbage collection cycle count */

pgssGlobalStatsstats;/* global statistics for pgss */

}pgssSharedState;

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);

staticvoidpgss_shmem_startup(void);

staticvoidpgss_shmem_shutdown(intcode,Datumarg);

pgss->extent=0;

pgss->n_writers=0;

pgss->gc_count=0;

pgss->stats.dealloc=0;

}

memset(&info,0,sizeof(info));

entry->counters=temp.counters;

}

if (fread(&pgss->stats,sizeof(pgssGlobalStats),1,file)!=1)

gotoread_error;

pfree(buffer);

FreeFile(file);

FreeFile(qfile);

}

}

if (fwrite(&pgss->stats,sizeof(pgssGlobalStats),1,file)!=1)

gotoerror;

free(qbuffer);

qbuffer=NULL;

tuplestore_donestoring(tupstore);

}

pg_stat_statements_info(PG_FUNCTION_ARGS)

{

pgssGlobalStatsstats;

{

volatilepgssSharedState*s= (volatilepgssSharedState*)pgss;

SpinLockAcquire(&s->mutex);

stats=s->stats;

SpinLockRelease(&s->mutex);

}

PG_RETURN_INT64(stats.dealloc);

}

}

pfree(entries);

{

volatilepgssSharedState*s= (volatilepgssSharedState*)pgss;

SpinLockAcquire(&s->mutex);

s->stats.dealloc+=1;

SpinLockRelease(&s->mutex);

}

}

hash_search(pgss_hash,&entry->key,HASH_REMOVE,NULL);

num_remove++;

}

{

volatilepgssSharedState*s= (volatilepgssSharedState*)pgss;

SpinLockAcquire(&s->mutex);

s->stats.dealloc=0;

SpinLockRelease(&s->mutex);

}

}

# 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

SELECT42;

SELECT query, plans, calls, rowsFROM pg_stat_statementsORDER BY query COLLATE"C";

SELECT pg_stat_statements_reset();

SELECT deallocFROM pg_stat_statements_info;

DROP EXTENSION pg_stat_statements;

<para>

When <filename>pg_stat_statements</filename> is loaded, it tracks

statistics across all databases of the server. To access and manipulate

these statistics, the module provides a view, <structname>pg_stat_statements</structname>,

these statistics, the module provides views

<structname>pg_stat_statements</structname> and

<structname>pg_stat_statements_info</structname>,

and the utility functions <function>pg_stat_statements_reset</function> and

<function>pg_stat_statements</function>. These are not available globally but

can be enabled for a specific database with

</para>

</sect2>

<sect2>

<title>The <structname>pg_stat_statements_info</structname> View</title>

<indexterm>

<primary>pg_stat_statements_info</primary>

</indexterm>

<para>

The statistics of the <filename>pg_stat_statements</filename> module

itself are tracked and made available via a view named

<structname>pg_stat_statements_info</structname>. This view contains

only a single row. The columns of the view are shown in

<xref linkend="pgstatstatementsinfo-columns"/>.

</para>

<table id="pgstatstatementsinfo-columns">

<title><structname>pg_stat_statements_info</structname> Columns</title>

<tgroup cols="1">

<thead>

<row>

<entry role="catalog_table_entry"><para role="column_definition">

Column Type

</para>

<para>

Description

</para></entry>

</row>

</thead>

<tbody>

<row>

<entry role="catalog_table_entry"><para role="column_definition">

<structfield>dealloc</structfield> <type>bigint</type>

</para>

<para>

Total number of times <structname>pg_stat_statements</structname>

entries about the least-executed statements were deallocated

because more distinct statements than

<varname>pg_stat_statements.max</varname> were observed

</para></entry>

</row>

</tbody>

</tgroup>

</table>

</sect2>

<sect2>

<title>Functions</title>

specified, the default value <literal>0</literal>(invalid) is used for

each of them and the statistics that match with other parameters will be

reset. If no parameter is specified or all the specified parameters are

<literal>0</literal>(invalid), it will discard all statistics. By

default, this function can only be executed by superusers. Access may be

granted to others using <command>GRANT</command>.

<literal>0</literal>(invalid), it will discard all statistics including

the statistics that <structname>pg_stat_statements_info</structname>

displays. By default, this function can only be executed by superusers.

Access may be granted to others using <command>GRANT</command>.

</para>

</listitem>

</varlistentry>

statements tracked by the module (i.e., the maximum number of rows

in the <structname>pg_stat_statements</structname> view). If more distinct

statements than that are observed, information about the least-executed

statements is discarded.

statements is discarded. The number of times such information was

discarded can be seen in the

<structname>pg_stat_statements_info</structname> view.

The default value is 5000.

This parameter can only be set at server start.

</para>

pgsocket

pgsql_thing_t

pgssEntry

pgssGlobalStats

pgssHashKey

pgssJumbleState

pgssLocationLen