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<?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>37.2. Data Types</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="infoschema-schema.html" title="37.1. The Schema" /><link rel="next" href="infoschema-information-schema-catalog-name.html" title="37.3. information_schema_catalog_name" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">37.2. Data Types</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="infoschema-schema.html" title="37.1. The Schema">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="information-schema.html" title="Chapter 37. The Information Schema">Up</a></td><th width="60%" align="center">Chapter 37. The Information Schema</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="infoschema-information-schema-catalog-name.html" title="37.3. information_schema_catalog_name">Next</a></td></tr></table><hr /></div><div class="sect1" id="INFOSCHEMA-DATATYPES"><div class="titlepage"><div><div><h2 class="title" style="clear: both">37.2. Data Types <a href="#INFOSCHEMA-DATATYPES" class="id_link">#</a></h2></div></div></div><p> The columns of the information schema views use special data types that are defined in the information schema. These are defined as simple domains over ordinary built-in types. You should not use these types for work outside the information schema, but your applications must be prepared for them if they select from the information schema. </p><p> These types are: </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="type">cardinal_number</code></span></dt><dd><p> A nonnegative integer. </p></dd><dt><span class="term"><code class="type">character_data</code></span></dt><dd><p> A character string (without specific maximum length). </p></dd><dt><span class="term"><code class="type">sql_identifier</code></span></dt><dd><p> A character string. This type is used for SQL identifiers, the type <code class="type">character_data</code> is used for any other kind of text data. </p></dd><dt><span class="term"><code class="type">time_stamp</code></span></dt><dd><p> A domain over the type <code class="type">timestamp with time zone</code> </p></dd><dt><span class="term"><code class="type">yes_or_no</code></span></dt><dd><p> A character string domain that contains either <code class="literal">YES</code> or <code class="literal">NO</code>. This is used to represent Boolean (true/false) data in the information schema. (The information schema was invented before the type <code class="type">boolean</code> was added to the SQL standard, so this convention is necessary to keep the information schema backward compatible.) </p></dd></dl></div><p> Every column in the information schema has one of these five types. </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="infoschema-schema.html" title="37.1. The Schema">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="information-schema.html" title="Chapter 37. The Information Schema">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="infoschema-information-schema-catalog-name.html" title="37.3. information_schema_catalog_name">Next</a></td></tr><tr><td width="40%" align="left" valign="top">37.1. The Schema </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"> 37.3. <code class="literal">information_schema_catalog_name</code></td></tr></table></div></body></html>