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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>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><div xmlns="http://www.w3.org/TR/xhtml1/transitional" 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 11.5 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></hr></div><div class="sect1" id="INFOSCHEMA-DATATYPES"><div class="titlepage"><div><div><h2 class="title" style="clear: both">37.2. Data Types</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">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="information-schema.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="infoschema-information-schema-catalog-name.html">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">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>
