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Documentation of the system catalogs, directed toward PostgreSQL developers

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$Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.78 2003/11/02 12:53:57 petere Exp $

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<chapter id="catalogs">

A composite type is automatically created for each table in the database, to

represent the row structure of the table. It is also possible to create

composite types with <command>CREATE TYPE AS</command> and

derived types with <command>CREATE DOMAIN</command>.

domains with <command>CREATE DOMAIN</command>.

</para>

<table>

<entry></entry>

<entry>

<structfield>typtype</structfield> is <literal>b</literal> for

a base type, <literal>c</literal> for a composite type (i.e.,

atable's row type), <literal>d</literal> for aderived type (i.e.,

a domain), or<literal>p</literal> for a pseudo-type. See also

<structfield>typrelid</structfield>

and<structfield>typbasetype</structfield>.

a base type, <literal>c</literal> for a composite type (i.e., a

table's row type), <literal>d</literal> for adomain, or

<literal>p</literal> for a pseudo-type. See also

<structfield>typrelid</structfield> and

<structfield>typbasetype</structfield>.

</entry>

</row>

<entry><type>oid</type></entry>

<entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>

<entry><para>

If this is aderived type (see <structfield>typtype</structfield>),

If this is adomain (see <structfield>typtype</structfield>),

then <structfield>typbasetype</structfield> identifies

the type that this one is based on. Zero if not aderived type.

the type that this one is based on. Zero if not adomain.

</para></entry>

</row>