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   2 <!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>52.53. pg_statistic_ext_data</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="catalog-pg-statistic-ext.html" title="52.52. pg_statistic_ext" /><link rel="next" href="catalog-pg-subscription.html" title="52.54. pg_subscription" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">52.53. <code class="structname">pg_statistic_ext_data</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="catalog-pg-statistic-ext.html" title="52.52. pg_statistic_ext">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="catalogs.html" title="Chapter 52. System Catalogs">Up</a></td><th width="60%" align="center">Chapter 52. System Catalogs</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="catalog-pg-subscription.html" title="52.54. pg_subscription">Next</a></td></tr></table><hr /></div><div class="sect1" id="CATALOG-PG-STATISTIC-EXT-DATA"><div class="titlepage"><div><div><h2 class="title" style="clear: both">52.53. <code class="structname">pg_statistic_ext_data</code> <a href="#CATALOG-PG-STATISTIC-EXT-DATA" class="id_link">#</a></h2></div></div></div><a id="id-1.10.4.55.2" class="indexterm"></a><p>
   3    The catalog <code class="structname">pg_statistic_ext_data</code>
   4    holds data for extended planner statistics defined in
   5    <a class="link" href="catalog-pg-statistic-ext.html" title="52.52. pg_statistic_ext"><code class="structname">pg_statistic_ext</code></a>.
   6    Each row in this catalog corresponds to a <em class="firstterm">statistics object</em>
   7    created with <a class="link" href="sql-createstatistics.html" title="CREATE STATISTICS"><code class="command">CREATE STATISTICS</code></a>.
   8   </p><p>
   9    Normally there is one entry, with <code class="structfield">stxdinherit</code> =
  10    <code class="literal">false</code>, for each statistics object that has been analyzed.
  11    If the table has inheritance children or partitions, a second entry with
  12    <code class="structfield">stxdinherit</code> = <code class="literal">true</code> is also created.
  13    This row represents the statistics object over the inheritance tree, i.e.,
  14    statistics for the data you'd see with
  15    <code class="literal">SELECT * FROM <em class="replaceable"><code>table</code></em>*</code>,
  16    whereas the <code class="structfield">stxdinherit</code> = <code class="literal">false</code> row
  17    represents the results of
  18    <code class="literal">SELECT * FROM ONLY <em class="replaceable"><code>table</code></em></code>.
  19   </p><p>
  20    Like <a class="link" href="catalog-pg-statistic.html" title="52.51. pg_statistic"><code class="structname">pg_statistic</code></a>,
  21    <code class="structname">pg_statistic_ext_data</code> should not be
  22    readable by the public, since the contents might be considered sensitive.
  23    (Example: most common combinations of values in columns might be quite
  24    interesting.)
  25    <a class="link" href="view-pg-stats-ext.html" title="53.30. pg_stats_ext"><code class="structname">pg_stats_ext</code></a>
  26    is a publicly readable view
  27    on <code class="structname">pg_statistic_ext_data</code> (after joining
  28    with <a class="link" href="catalog-pg-statistic-ext.html" title="52.52. pg_statistic_ext"><code class="structname">pg_statistic_ext</code></a>) that only exposes
  29    information about tables the current user owns.
  30   </p><div class="table" id="id-1.10.4.55.6"><p class="title"><strong>Table 52.53. <code class="structname">pg_statistic_ext_data</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_statistic_ext_data Columns" border="1"><colgroup><col /></colgroup><thead><tr><th class="catalog_table_entry"><p class="column_definition">
  31        Column Type
  32       </p>
  33       <p>
  34        Description
  35       </p></th></tr></thead><tbody><tr><td class="catalog_table_entry"><p class="column_definition">
  36        <code class="structfield">stxoid</code> <code class="type">oid</code>
  37        (references <a class="link" href="catalog-pg-statistic-ext.html" title="52.52. pg_statistic_ext"><code class="structname">pg_statistic_ext</code></a>.<code class="structfield">oid</code>)
  38       </p>
  39       <p>
  40        Extended statistics object containing the definition for this data
  41       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  42        <code class="structfield">stxdinherit</code> <code class="type">bool</code>
  43       </p>
  44       <p>
  45        If true, the stats include values from child tables, not just the
  46        values in the specified relation
  47       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  48        <code class="structfield">stxdndistinct</code> <code class="type">pg_ndistinct</code>
  49       </p>
  50       <p>
  51        N-distinct counts, serialized as <code class="structname">pg_ndistinct</code> type
  52       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  53        <code class="structfield">stxddependencies</code> <code class="type">pg_dependencies</code>
  54       </p>
  55       <p>
  56        Functional dependency statistics, serialized
  57        as <code class="structname">pg_dependencies</code> type
  58       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  59        <code class="structfield">stxdmcv</code> <code class="type">pg_mcv_list</code>
  60       </p>
  61       <p>
  62        MCV (most-common values) list statistics, serialized as
  63        <code class="structname">pg_mcv_list</code> type
  64       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  65        <code class="structfield">stxdexpr</code> <code class="type">pg_statistic[]</code>
  66       </p>
  67       <p>
  68        Per-expression statistics, serialized as an array of
  69        <code class="structname">pg_statistic</code> type
  70       </p></td></tr></tbody></table></div></div><br class="table-break" /></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="catalog-pg-statistic-ext.html" title="52.52. pg_statistic_ext">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="catalogs.html" title="Chapter 52. System Catalogs">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="catalog-pg-subscription.html" title="52.54. pg_subscription">Next</a></td></tr><tr><td width="40%" align="left" valign="top">52.52. <code class="structname">pg_statistic_ext</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 52.54. <code class="structname">pg_subscription</code></td></tr></table></div></body></html>