database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-20 15:22:23 +03:00
Code Activity

Add CASCADE option to TRUNCATE. Joachim Wieland

Browse Source
This commit is contained in:
Tom Lane
2006-03-03 03:30:54 +00:00
parent 2a0ba3f8dd
commit 984a6ced3e
12 changed files with 252 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
doc/src/sgml/ref/truncate.sgml
View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/truncate.sgml,v 1.19 2005/02/22 19:06:18 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/truncate.sgml,v 1.20 2006/03/03 03:30:52 tgl Exp $
PostgreSQL documentation
-->
@ -20,7 +20,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...]
TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@ -47,6 +47,27 @@ TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...]
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>CASCADE</literal></term>
<listitem>
<para>
Automatically truncate all tables that have foreign-key references
to any of the named tables, or to any tables added to the group
due to <literal>CASCADE</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>RESTRICT</literal></term>
<listitem>
<para>
Refuse to truncate if any of the tables have foreign-key references
from tables that are not to be truncated. This is the default.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
@ -61,7 +82,10 @@ TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...]
<command>TRUNCATE</> cannot be used on a table that has foreign-key
references from other tables, unless all such tables are also truncated
in the same command. Checking validity in such cases would require table
scans, and the whole point is not to do one.
scans, and the whole point is not to do one. The <literal>CASCADE</>
option can be used to automatically include all dependent tables &mdash;
but be very careful when using this option, else you might lose data you
did not intend to!
</para>
<para>
@ -78,10 +102,20 @@ TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable> [, ...]
<programlisting>
TRUNCATE TABLE bigtable, fattable;
</programlisting>
</para>
<para>
Truncate the table <literal>othertable</literal>, and cascade to any tables
that are referencing <literal>othertable</literal> via foreign-key
constraints:
<programlisting>
TRUNCATE othertable CASCADE;
</programlisting>
</para>
</refsect1>
<refsect1>
<title>Compatibility</title>