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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>54.26. pg_shmem_allocations</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="view-pg-shadow.html" title="54.25. pg_shadow" /><link rel="next" href="view-pg-stats.html" title="54.27. pg_stats" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">54.26. <code class="structname">pg_shmem_allocations</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="view-pg-shadow.html" title="54.25. pg_shadow">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="views.html" title="Chapter 54. System Views">Up</a></td><th width="60%" align="center">Chapter 54. System Views</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 15.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="view-pg-stats.html" title="54.27. pg_stats">Next</a></td></tr></table><hr /></div><div class="sect1" id="VIEW-PG-SHMEM-ALLOCATIONS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">54.26. <code class="structname">pg_shmem_allocations</code></h2></div></div></div><a id="id-1.10.5.30.2" class="indexterm"></a><p>
   The <code class="structname">pg_shmem_allocations</code> view shows allocations
   made from the server's main shared memory segment.  This includes both
   memory allocated by <span class="productname">PostgreSQL</span> itself and memory
   allocated by extensions using the mechanisms detailed in
   <a class="xref" href="xfunc-c.html#XFUNC-SHARED-ADDIN" title="38.10.10. Shared Memory and LWLocks">Section 38.10.10</a>.
  </p><p>
   Note that this view does not include memory allocated using the dynamic
   shared memory infrastructure.
  </p><div class="table" id="id-1.10.5.30.5"><p class="title"><strong>Table 54.26. <code class="structname">pg_shmem_allocations</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_shmem_allocations Columns" border="1"><colgroup><col /></colgroup><thead><tr><th class="catalog_table_entry"><p class="column_definition">
       Column Type
      </p>
      <p>
       Description
      </p></th></tr></thead><tbody><tr><td class="catalog_table_entry"><p class="column_definition">
       <code class="structfield">name</code> <code class="type">text</code>
      </p>
      <p>
       The name of the shared memory allocation. NULL for unused memory
       and <code class="literal">&lt;anonymous&gt;</code> for anonymous
       allocations.
      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
       <code class="structfield">off</code> <code class="type">int8</code>
      </p>
      <p>
       The offset at which the allocation starts. NULL for anonymous
       allocations, since details related to them are not known.
      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
       <code class="structfield">size</code> <code class="type">int8</code>
      </p>
      <p>
       Size of the allocation
      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
       <code class="structfield">allocated_size</code> <code class="type">int8</code>
      </p>
      <p>
       Size of the allocation including padding. For anonymous
       allocations, no information about padding is available, so the
       <code class="literal">size</code> and <code class="literal">allocated_size</code> columns
       will always be equal. Padding is not meaningful for free memory, so
       the columns will be equal in that case also.
      </p></td></tr></tbody></table></div></div><br class="table-break" /><p>
   Anonymous allocations are allocations that have been made
   with <code class="literal">ShmemAlloc()</code> directly, rather than via
   <code class="literal">ShmemInitStruct()</code> or
   <code class="literal">ShmemInitHash()</code>.
  </p><p>
   By default, the <code class="structname">pg_shmem_allocations</code> view can be
   read only by superusers or roles with privileges of the
   <code class="literal">pg_read_all_stats</code> role.
  </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="view-pg-shadow.html" title="54.25. pg_shadow">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="views.html" title="Chapter 54. System Views">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="view-pg-stats.html" title="54.27. pg_stats">Next</a></td></tr><tr><td width="40%" align="left" valign="top">54.25. <code class="structname">pg_shadow</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 54.27. <code class="structname">pg_stats</code></td></tr></table></div></body></html>