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diff --git a/doc/src/sgml/html/catalog-pg-collation.html b/doc/src/sgml/html/catalog-pg-collation.html new file mode 100644 index 0000000..65e8e82 --- /dev/null +++ b/doc/src/sgml/html/catalog-pg-collation.html @@ -0,0 +1,93 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!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>53.12. pg_collation</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-class.html" title="53.11. pg_class" /><link rel="next" href="catalog-pg-constraint.html" title="53.13. pg_constraint" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">53.12. <code class="structname">pg_collation</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="catalog-pg-class.html" title="53.11. pg_class">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 15.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="catalog-pg-constraint.html" title="53.13. pg_constraint">Next</a></td></tr></table><hr /></div><div class="sect1" id="CATALOG-PG-COLLATION"><div class="titlepage"><div><div><h2 class="title" style="clear: both">53.12. <code class="structname">pg_collation</code></h2></div></div></div><a id="id-1.10.4.14.2" class="indexterm"></a><p> + The catalog <code class="structname">pg_collation</code> describes the + available collations, which are essentially mappings from an SQL + name to operating system locale categories. + See <a class="xref" href="collation.html" title="24.2. Collation Support">Section 24.2</a> for more information. + </p><div class="table" id="id-1.10.4.14.4"><p class="title"><strong>Table 53.12. <code class="structname">pg_collation</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_collation 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">oid</code> <code class="type">oid</code> + </p> + <p> + Row identifier + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collname</code> <code class="type">name</code> + </p> + <p> + Collation name (unique per namespace and encoding) + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collnamespace</code> <code class="type">oid</code> + (references <a class="link" href="catalog-pg-namespace.html" title="53.32. pg_namespace"><code class="structname">pg_namespace</code></a>.<code class="structfield">oid</code>) + </p> + <p> + The OID of the namespace that contains this collation + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collowner</code> <code class="type">oid</code> + (references <a class="link" href="catalog-pg-authid.html" title="53.8. pg_authid"><code class="structname">pg_authid</code></a>.<code class="structfield">oid</code>) + </p> + <p> + Owner of the collation + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collprovider</code> <code class="type">char</code> + </p> + <p> + Provider of the collation: <code class="literal">d</code> = database + default, <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"> + <code class="structfield">collisdeterministic</code> <code class="type">bool</code> + </p> + <p> + Is the collation deterministic? + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collencoding</code> <code class="type">int4</code> + </p> + <p> + Encoding in which the collation is applicable, or -1 if it + works for any encoding + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collcollate</code> <code class="type">text</code> + </p> + <p> + <code class="symbol">LC_COLLATE</code> for this collation object + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collctype</code> <code class="type">text</code> + </p> + <p> + <code class="symbol">LC_CTYPE</code> for this collation object + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">colliculocale</code> <code class="type">text</code> + </p> + <p> + ICU locale ID for this collation object + </p></td></tr><tr><td class="catalog_table_entry"><p class="column_definition"> + <code class="structfield">collversion</code> <code class="type">text</code> + </p> + <p> + Provider-specific version of the collation. This is recorded when the + collation is created and then checked when it is used, to detect + changes in the collation definition that could lead to data corruption. + </p></td></tr></tbody></table></div></div><br class="table-break" /><p> + Note that the unique key on this catalog is (<code class="structfield">collname</code>, + <code class="structfield">collencoding</code>, <code class="structfield">collnamespace</code>) not just + (<code class="structfield">collname</code>, <code class="structfield">collnamespace</code>). + <span class="productname">PostgreSQL</span> generally ignores all + collations that do not have <code class="structfield">collencoding</code> equal to + either the current database's encoding or -1, and creation of new entries + with the same name as an entry with <code class="structfield">collencoding</code> = -1 + is forbidden. Therefore it is sufficient to use a qualified SQL name + (<em class="replaceable"><code>schema</code></em>.<em class="replaceable"><code>name</code></em>) to identify a collation, + even though this is not unique according to the catalog definition. + The reason for defining the catalog this way is that + <span class="application">initdb</span> fills it in at cluster initialization time with + entries for all locales available on the system, so it must be able to + hold entries for all encodings that might ever be used in the cluster. + </p><p> + In the <code class="literal">template0</code> database, it could be useful to create + collations whose encoding does not match the database encoding, + since they could match the encodings of databases later cloned from + <code class="literal">template0</code>. This would currently have to be done manually. + </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="catalog-pg-class.html" title="53.11. pg_class">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-constraint.html" title="53.13. pg_constraint">Next</a></td></tr><tr><td width="40%" align="left" valign="top">53.11. <code class="structname">pg_class</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 53.13. <code class="structname">pg_constraint</code></td></tr></table></div></body></html>
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