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1<?xml version="1.0" encoding="UTF-8" standalone="no"?>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>53.48. pg_shdepend</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-sequence.html" title="53.47. pg_sequence" /><link rel="next" href="catalog-pg-shdescription.html" title="53.49. pg_shdescription" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">53.48. <code class="structname">pg_shdepend</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="catalog-pg-sequence.html" title="53.47. pg_sequence">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="catalogs.html" title="Chapter 53. System Catalogs">Up</a></td><th width="60%" align="center">Chapter 53. System Catalogs</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="catalog-pg-shdescription.html" title="53.49. pg_shdescription">Next</a></td></tr></table><hr /></div><div class="sect1" id="CATALOG-PG-SHDEPEND"><div class="titlepage"><div><div><h2 class="title" style="clear: both">53.48. <code class="structname">pg_shdepend</code> <a href="#CATALOG-PG-SHDEPEND" class="id_link">#</a></h2></div></div></div><a id="id-1.10.4.50.2" class="indexterm"></a><p>3   The catalog <code class="structname">pg_shdepend</code> records the4   dependency relationships between database objects and shared objects,5   such as roles.  This information allows6   <span class="productname">PostgreSQL</span> to ensure that those objects are7   unreferenced before attempting to delete them.8  </p><p>9   See also <a class="link" href="catalog-pg-depend.html" title="53.18. pg_depend"><code class="structname">pg_depend</code></a>,10   which performs a similar function for dependencies involving objects11   within a single database.12  </p><p>13   Unlike most system catalogs, <code class="structname">pg_shdepend</code>14   is shared across all databases of a cluster: there is only one15   copy of <code class="structname">pg_shdepend</code> per cluster, not16   one per database.17  </p><div class="table" id="id-1.10.4.50.6"><p class="title"><strong>Table 53.48. <code class="structname">pg_shdepend</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_shdepend Columns" border="1"><colgroup><col /></colgroup><thead><tr><th class="catalog_table_entry"><p class="column_definition">18       Column Type19      </p>20      <p>21       Description22      </p></th></tr></thead><tbody><tr><td class="catalog_table_entry"><p class="column_definition">23       <code class="structfield">dbid</code> <code class="type">oid</code>24       (references <a class="link" href="catalog-pg-database.html" title="53.15. pg_database"><code class="structname">pg_database</code></a>.<code class="structfield">oid</code>)25      </p>26      <p>27       The OID of the database the dependent object is in,28       or zero for a shared object29      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">30       <code class="structfield">classid</code> <code class="type">oid</code>31       (references <a class="link" href="catalog-pg-class.html" title="53.11. pg_class"><code class="structname">pg_class</code></a>.<code class="structfield">oid</code>)32      </p>33      <p>34       The OID of the system catalog the dependent object is in35      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">36       <code class="structfield">objid</code> <code class="type">oid</code>37       (references any OID column)38      </p>39      <p>40       The OID of the specific dependent object41      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">42       <code class="structfield">objsubid</code> <code class="type">int4</code>43      </p>44      <p>45       For a table column, this is the column number (the46       <code class="structfield">objid</code> and <code class="structfield">classid</code> refer to the47       table itself).  For all other object types, this column is zero.48      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">49       <code class="structfield">refclassid</code> <code class="type">oid</code>50       (references <a class="link" href="catalog-pg-class.html" title="53.11. pg_class"><code class="structname">pg_class</code></a>.<code class="structfield">oid</code>)51      </p>52      <p>53       The OID of the system catalog the referenced object is in54       (must be a shared catalog)55      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">56       <code class="structfield">refobjid</code> <code class="type">oid</code>57       (references any OID column)58      </p>59      <p>60       The OID of the specific referenced object61      </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">62       <code class="structfield">deptype</code> <code class="type">char</code>63      </p>64      <p>65       A code defining the specific semantics of this dependency relationship; see text66      </p></td></tr></tbody></table></div></div><br class="table-break" /><p>67   In all cases, a <code class="structname">pg_shdepend</code> entry indicates that68   the referenced object cannot be dropped without also dropping the dependent69   object.  However, there are several subflavors identified by70   <code class="structfield">deptype</code>:71 72   </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="symbol">SHARED_DEPENDENCY_OWNER</code> (<code class="literal">o</code>)</span></dt><dd><p>73       The referenced object (which must be a role) is the owner of the74       dependent object.75      </p></dd><dt><span class="term"><code class="symbol">SHARED_DEPENDENCY_ACL</code> (<code class="literal">a</code>)</span></dt><dd><p>76       The referenced object (which must be a role) is mentioned in the77       ACL (access control list, i.e., privileges list) of the78       dependent object.  (A <code class="symbol">SHARED_DEPENDENCY_ACL</code> entry is79       not made for the owner of the object, since the owner will have80       a <code class="symbol">SHARED_DEPENDENCY_OWNER</code> entry anyway.)81      </p></dd><dt><span class="term"><code class="symbol">SHARED_DEPENDENCY_POLICY</code> (<code class="literal">r</code>)</span></dt><dd><p>82       The referenced object (which must be a role) is mentioned as the83       target of a dependent policy object.84      </p></dd><dt><span class="term"><code class="symbol">SHARED_DEPENDENCY_TABLESPACE</code> (<code class="literal">t</code>)</span></dt><dd><p>85       The referenced object (which must be a tablespace) is mentioned as86       the tablespace for a relation that doesn't have storage.87      </p></dd></dl></div><p>88 89   Other dependency flavors might be needed in future.  Note in particular90   that the current definition only supports roles and tablespaces as referenced91   objects.92  </p><p>93   As in the <code class="structname">pg_depend</code> catalog, most objects94   created during <span class="application">initdb</span> are95   considered <span class="quote">“<span class="quote">pinned</span>”</span>.  No entries are made96   in <code class="structname">pg_shdepend</code> that would have a pinned97   object as either referenced or dependent object.98  </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="catalog-pg-sequence.html" title="53.47. pg_sequence">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="catalogs.html" title="Chapter 53. System Catalogs">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="catalog-pg-shdescription.html" title="53.49. pg_shdescription">Next</a></td></tr><tr><td width="40%" align="left" valign="top">53.47. <code class="structname">pg_sequence</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 53.49. <code class="structname">pg_shdescription</code></td></tr></table></div></body></html>