diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/pgstatstatements.sgml | 61 |
1 files changed, 56 insertions, 5 deletions
diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml index cf2d25b7b22..81915ea69bb 100644 --- a/doc/src/sgml/pgstatstatements.sgml +++ b/doc/src/sgml/pgstatstatements.sgml @@ -23,7 +23,9 @@ <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 @@ -481,6 +483,52 @@ </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> <variablelist> @@ -501,9 +549,10 @@ 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> @@ -555,7 +604,9 @@ 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> |