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105 lines
2.3 KiB
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105 lines
2.3 KiB
Plaintext
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$PostgreSQL: pgsql/doc/src/sgml/ref/truncate.sgml,v 1.16 2003/11/29 19:51:39 pgsql Exp $
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PostgreSQL documentation
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-->
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<refentry id="SQL-TRUNCATE">
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<refmeta>
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<refentrytitle id="SQL-TRUNCATE-TITLE">TRUNCATE</refentrytitle>
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<refmiscinfo>SQL - Language Statements</refmiscinfo>
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</refmeta>
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<refnamediv>
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<refname>TRUNCATE</refname>
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<refpurpose>empty a table</refpurpose>
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</refnamediv>
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<indexterm zone="sql-truncate">
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<primary>TRUNCATE</primary>
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</indexterm>
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<refsynopsisdiv>
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<synopsis>
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TRUNCATE [ TABLE ] <replaceable class="PARAMETER">name</replaceable>
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</synopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>
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<command>TRUNCATE</command> quickly removes all rows from a
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table. It has the same effect as an unqualified
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<command>DELETE</command> but since it does not actually scan the
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table it is faster. This is most useful on large tables.
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</para>
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</refsect1>
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<refsect1>
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<title>Parameters</title>
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<variablelist>
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<varlistentry>
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<term><replaceable class="PARAMETER">name</replaceable></term>
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<listitem>
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<para>
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The name (optionally schema-qualified) of the table to be truncated.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>Notes</title>
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<para>
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<command>TRUNCATE</> cannot be used if there are foreign-key references
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to the table from other tables. Checking validity in such cases would
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require table scans, and the whole point is not to do one.
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</para>
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<para>
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<command>TRUNCATE</> will not run any user-defined ON DELETE triggers
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that might exist for the table.
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</para>
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</refsect1>
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<refsect1>
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<title>Examples</title>
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<para>
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Truncate the table <literal>bigtable</literal>:
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<programlisting>
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TRUNCATE TABLE bigtable;
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</programlisting>
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</para>
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</refsect1>
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<refsect1>
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<title>Compatibility</title>
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<para>
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There is no <command>TRUNCATE</command> command in the SQL standard.
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</para>
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</refsect1>
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</refentry>
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<!-- Keep this comment at the end of the file
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Local variables:
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mode: sgml
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sgml-omittag:t
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sgml-shorttag:t
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sgml-minimize-attributes:nil
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sgml-always-quote-attributes:t
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sgml-indent-step:1
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sgml-indent-data:t
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sgml-parent-document:nil
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sgml-default-dtd-file:"../reference.ced"
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sgml-exposed-tags:nil
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sgml-local-catalogs:"/usr/lib/sgml/catalog"
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sgml-local-ecat-files:nil
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End:
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-->
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