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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>19.9. Run-time Statistics</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="runtime-config-logging.html" title="19.8. Error Reporting and Logging" /><link rel="next" href="runtime-config-autovacuum.html" title="19.10. Automatic Vacuuming" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">19.9. Run-time Statistics</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="runtime-config-logging.html" title="19.8. Error Reporting and Logging">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="runtime-config.html" title="Chapter 19. Server Configuration">Up</a></td><th width="60%" align="center">Chapter 19. Server Configuration</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="runtime-config-autovacuum.html" title="19.10. Automatic Vacuuming">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RUNTIME-CONFIG-STATISTICS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">19.9. Run-time Statistics</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="runtime-config-statistics.html#RUNTIME-CONFIG-STATISTICS-COLLECTOR">19.9.1. Query and Index Statistics Collector</a></span></dt><dt><span class="sect2"><a href="runtime-config-statistics.html#RUNTIME-CONFIG-STATISTICS-MONITOR">19.9.2. Statistics Monitoring</a></span></dt></dl></div><div class="sect2" id="RUNTIME-CONFIG-STATISTICS-COLLECTOR"><div class="titlepage"><div><div><h3 class="title">19.9.1. Query and Index Statistics Collector</h3></div></div></div><p>
These parameters control server-wide statistics collection features.
When statistics collection is enabled, the data that is produced can be
accessed via the <code class="structname">pg_stat</code> and
<code class="structname">pg_statio</code> family of system views.
Refer to <a class="xref" href="monitoring.html" title="Chapter 28. Monitoring Database Activity">Chapter 28</a> for more information.
</p><div class="variablelist"><dl class="variablelist"><dt id="GUC-TRACK-ACTIVITIES"><span class="term"><code class="varname">track_activities</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.2.3.1.1.3" class="indexterm"></a>
</span></dt><dd><p>
Enables the collection of information on the currently
executing command of each session, along with the time when
that command began execution. This parameter is on by
default. Note that even when enabled, this information is not
visible to all users, only to superusers and the user owning
the session being reported on, so it should not represent a
security risk.
Only superusers can change this setting.
</p></dd><dt id="GUC-TRACK-ACTIVITY-QUERY-SIZE"><span class="term"><code class="varname">track_activity_query_size</code> (<code class="type">integer</code>)
<a id="id-1.6.6.12.2.3.2.1.3" class="indexterm"></a>
</span></dt><dd><p>
Specifies the number of bytes reserved to track the currently
executing command for each active session, for the
<code class="structname">pg_stat_activity</code>.<code class="structfield">query</code> field.
The default value is 1024. This parameter can only be set at server
start.
</p></dd><dt id="GUC-TRACK-COUNTS"><span class="term"><code class="varname">track_counts</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.2.3.3.1.3" class="indexterm"></a>
</span></dt><dd><p>
Enables collection of statistics on database activity.
This parameter is on by default, because the autovacuum
daemon needs the collected information.
Only superusers can change this setting.
</p></dd><dt id="GUC-TRACK-IO-TIMING"><span class="term"><code class="varname">track_io_timing</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.2.3.4.1.3" class="indexterm"></a>
</span></dt><dd><p>
Enables timing of database I/O calls. This parameter is off by
default, because it will repeatedly query the operating system for
the current time, which may cause significant overhead on some
platforms. You can use the <a class="xref" href="pgtesttiming.html" title="pg_test_timing"><span class="refentrytitle"><span class="application">pg_test_timing</span></span></a> tool to
measure the overhead of timing on your system.
I/O timing information is
displayed in <a class="xref" href="monitoring-stats.html#PG-STAT-DATABASE-VIEW" title="Table 28.11. pg_stat_database View">pg_stat_database</a>, in the output of
<a class="xref" href="sql-explain.html" title="EXPLAIN"><span class="refentrytitle">EXPLAIN</span></a> when the <code class="literal">BUFFERS</code> option is
used, and by <a class="xref" href="pgstatstatements.html" title="F.29. pg_stat_statements">pg_stat_statements</a>. Only superusers can
change this setting.
</p></dd><dt id="GUC-TRACK-FUNCTIONS"><span class="term"><code class="varname">track_functions</code> (<code class="type">enum</code>)
<a id="id-1.6.6.12.2.3.5.1.3" class="indexterm"></a>
</span></dt><dd><p>
Enables tracking of function call counts and time used. Specify
<code class="literal">pl</code> to track only procedural-language functions,
<code class="literal">all</code> to also track SQL and C language functions.
The default is <code class="literal">none</code>, which disables function
statistics tracking. Only superusers can change this setting.
</p><div class="note"><h3 class="title">Note</h3><p>
SQL-language functions that are simple enough to be <span class="quote">“<span class="quote">inlined</span>”</span>
into the calling query will not be tracked, regardless of this
setting.
</p></div></dd><dt id="GUC-STATS-TEMP-DIRECTORY"><span class="term"><code class="varname">stats_temp_directory</code> (<code class="type">string</code>)
<a id="id-1.6.6.12.2.3.6.1.3" class="indexterm"></a>
</span></dt><dd><p>
Sets the directory to store temporary statistics data in. This can be
a path relative to the data directory or an absolute path. The default
is <code class="filename">pg_stat_tmp</code>. Pointing this at a RAM-based
file system will decrease physical I/O requirements and can lead to
improved performance.
This parameter can only be set in the <code class="filename">postgresql.conf</code>
file or on the server command line.
</p></dd></dl></div></div><div class="sect2" id="RUNTIME-CONFIG-STATISTICS-MONITOR"><div class="titlepage"><div><div><h3 class="title">19.9.2. Statistics Monitoring</h3></div></div></div><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="varname">log_statement_stats</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.3.2.1.1.3" class="indexterm"></a>
<br /></span><span class="term"><code class="varname">log_parser_stats</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.3.2.1.2.3" class="indexterm"></a>
<br /></span><span class="term"><code class="varname">log_planner_stats</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.3.2.1.3.3" class="indexterm"></a>
<br /></span><span class="term"><code class="varname">log_executor_stats</code> (<code class="type">boolean</code>)
<a id="id-1.6.6.12.3.2.1.4.3" class="indexterm"></a>
</span></dt><dd><p>
For each query, output performance statistics of the respective
module to the server log. This is a crude profiling
instrument, similar to the Unix <code class="function">getrusage()</code> operating
system facility. <code class="varname">log_statement_stats</code> reports total
statement statistics, while the others report per-module statistics.
<code class="varname">log_statement_stats</code> cannot be enabled together with
any of the per-module options. All of these options are disabled by
default. Only superusers can change these settings.
</p></dd></dl></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="runtime-config-logging.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="runtime-config.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="runtime-config-autovacuum.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">19.8. Error Reporting and Logging </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 19.10. Automatic Vacuuming</td></tr></table></div></body></html>
