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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>52.15. pg_database</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-conversion.html" title="52.14. pg_conversion" /><link rel="next" href="catalog-pg-db-role-setting.html" title="52.16. pg_db_role_setting" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">52.15. <code class="structname">pg_database</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="catalog-pg-conversion.html" title="52.14. pg_conversion">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-db-role-setting.html" title="52.16. pg_db_role_setting">Next</a></td></tr></table><hr /></div><div class="sect1" id="CATALOG-PG-DATABASE"><div class="titlepage"><div><div><h2 class="title" style="clear: both">52.15. <code class="structname">pg_database</code> <a href="#CATALOG-PG-DATABASE" class="id_link">#</a></h2></div></div></div><a id="id-1.10.4.17.2" class="indexterm"></a><p>
   3    The catalog <code class="structname">pg_database</code> stores information about
   4    the available databases.  Databases are created with the <a class="link" href="sql-createdatabase.html" title="CREATE DATABASE"><code class="command">CREATE DATABASE</code></a> command.
   5    Consult <a class="xref" href="managing-databases.html" title="Chapter 22. Managing Databases">Chapter 22</a> for details about the meaning
   6    of some of the parameters.
   7   </p><p>
   8    Unlike most system catalogs, <code class="structname">pg_database</code>
   9    is shared across all databases of a cluster: there is only one
  10    copy of <code class="structname">pg_database</code> per cluster, not
  11    one per database.
  12   </p><div class="table" id="id-1.10.4.17.5"><p class="title"><strong>Table 52.15. <code class="structname">pg_database</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_database Columns" border="1"><colgroup><col /></colgroup><thead><tr><th class="catalog_table_entry"><p class="column_definition">
  13        Column Type
  14       </p>
  15       <p>
  16        Description
  17       </p></th></tr></thead><tbody><tr><td class="catalog_table_entry"><p class="column_definition">
  18        <code class="structfield">oid</code> <code class="type">oid</code>
  19       </p>
  20       <p>
  21        Row identifier
  22       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  23        <code class="structfield">datname</code> <code class="type">name</code>
  24       </p>
  25       <p>
  26        Database name
  27       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  28        <code class="structfield">datdba</code> <code class="type">oid</code>
  29        (references <a class="link" href="catalog-pg-authid.html" title="52.8. pg_authid"><code class="structname">pg_authid</code></a>.<code class="structfield">oid</code>)
  30       </p>
  31       <p>
  32        Owner of the database, usually the user who created it
  33       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  34        <code class="structfield">encoding</code> <code class="type">int4</code>
  35       </p>
  36       <p>
  37        Character encoding for this database
  38        (<a class="link" href="functions-info.html#PG-ENCODING-TO-CHAR"><code class="function">pg_encoding_to_char()</code></a> can translate
  39        this number to the encoding name)
  40       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  41        <code class="structfield">datlocprovider</code> <code class="type">char</code>
  42       </p>
  43       <p>
  44        Locale provider for this database: <code class="literal">b</code> = builtin,
  45        <code class="literal">c</code> = libc, <code class="literal">i</code> = icu </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  46        <code class="structfield">datistemplate</code> <code class="type">bool</code>
  47       </p>
  48       <p>
  49        If true, then this database can be cloned by
  50        any user with <code class="literal">CREATEDB</code> privileges;
  51        if false, then only superusers or the owner of
  52        the database can clone it.
  53       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  54        <code class="structfield">datallowconn</code> <code class="type">bool</code>
  55       </p>
  56       <p>
  57        If false then no one can connect to this database.  This is
  58        used to protect the <code class="literal">template0</code> database from being altered.
  59       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  60        <code class="structfield">dathasloginevt</code> <code class="type">bool</code>
  61       </p>
  62       <p>
  63         Indicates that there are login event triggers defined for this database.
  64         This flag is used to avoid extra lookups on the
  65         <code class="structname">pg_event_trigger</code> table during each backend
  66         startup.  This flag is used internally by <span class="productname">PostgreSQL</span>
  67         and should not be manually altered or read for monitoring purposes.
  68       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  69        <code class="structfield">datconnlimit</code> <code class="type">int4</code>
  70       </p>
  71       <p>
  72        Sets maximum number of concurrent connections that can be made
  73        to this database.  -1 means no limit, -2 indicates the database is
  74        invalid.
  75       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  76        <code class="structfield">datfrozenxid</code> <code class="type">xid</code>
  77       </p>
  78       <p>
  79        All transaction IDs before this one have been replaced with a permanent
  80        (<span class="quote">“<span class="quote">frozen</span>”</span>) transaction ID in this database.  This is used to
  81        track whether the database needs to be vacuumed in order to prevent
  82        transaction ID wraparound or to allow <code class="literal">pg_xact</code> to be shrunk.
  83        It is the minimum of the per-table
  84        <a class="link" href="catalog-pg-class.html" title="52.11. pg_class"><code class="structname">pg_class</code></a>.<code class="structfield">relfrozenxid</code> values.
  85       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  86        <code class="structfield">datminmxid</code> <code class="type">xid</code>
  87       </p>
  88       <p>
  89        All multixact IDs before this one have been replaced with a
  90        transaction ID in this database.  This is used to
  91        track whether the database needs to be vacuumed in order to prevent
  92        multixact ID wraparound or to allow <code class="literal">pg_multixact</code> to be shrunk.
  93        It is the minimum of the per-table
  94        <a class="link" href="catalog-pg-class.html" title="52.11. pg_class"><code class="structname">pg_class</code></a>.<code class="structfield">relminmxid</code> values.
  95       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
  96        <code class="structfield">dattablespace</code> <code class="type">oid</code>
  97        (references <a class="link" href="catalog-pg-tablespace.html" title="52.56. pg_tablespace"><code class="structname">pg_tablespace</code></a>.<code class="structfield">oid</code>)
  98       </p>
  99       <p>
 100        The default tablespace for the database.
 101        Within this database, all tables for which
 102        <a class="link" href="catalog-pg-class.html" title="52.11. pg_class"><code class="structname">pg_class</code></a>.<code class="structfield">reltablespace</code> is zero
 103        will be stored in this tablespace; in particular, all the non-shared
 104        system catalogs will be there.
 105       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
 106        <code class="structfield">datcollate</code> <code class="type">text</code>
 107       </p>
 108       <p>
 109        LC_COLLATE for this database
 110       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
 111        <code class="structfield">datctype</code> <code class="type">text</code>
 112       </p>
 113       <p>
 114        LC_CTYPE for this database
 115       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
 116        <code class="structfield">datlocale</code> <code class="type">text</code>
 117       </p>
 118       <p>
 119        Collation provider locale name for this database. If the
 120        provider is <code class="literal">libc</code>,
 121        <code class="structfield">datlocale</code> is <code class="literal">NULL</code>;
 122        <code class="structfield">datcollate</code> and
 123        <code class="structfield">datctype</code> are used instead.
 124       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
 125        <code class="structfield">daticurules</code> <code class="type">text</code>
 126       </p>
 127       <p>
 128        ICU collation rules for this database
 129       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
 130        <code class="structfield">datcollversion</code> <code class="type">text</code>
 131       </p>
 132       <p>
 133        Provider-specific version of the collation.  This is recorded when the
 134        database is created and then checked when it is used, to detect
 135        changes in the collation definition that could lead to data corruption.
 136       </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition">
 137        <code class="structfield">datacl</code> <code class="type">aclitem[]</code>
 138       </p>
 139       <p>
 140        Access privileges; see <a class="xref" href="ddl-priv.html" title="5.8. Privileges">Section 5.8</a> for details
 141       </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-conversion.html" title="52.14. pg_conversion">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-db-role-setting.html" title="52.16. pg_db_role_setting">Next</a></td></tr><tr><td width="40%" align="left" valign="top">52.14. <code class="structname">pg_conversion</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"> 52.16. <code class="structname">pg_db_role_setting</code></td></tr></table></div></body></html>