109 lines
2.4 KiB
Plaintext
109 lines
2.4 KiB
Plaintext
<!--
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$PostgreSQL: pgsql/doc/src/sgml/ref/discard.sgml,v 1.3 2008/11/14 10:22:46 petere Exp $
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PostgreSQL documentation
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-->
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<refentry id="SQL-DISCARD">
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<refmeta>
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<refentrytitle id="SQL-DISCARD-TITLE">DISCARD</refentrytitle>
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<manvolnum>7</manvolnum>
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<refmiscinfo>SQL - Language Statements</refmiscinfo>
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</refmeta>
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<refnamediv>
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<refname>DISCARD</refname>
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<refpurpose>discard session state</refpurpose>
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</refnamediv>
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<indexterm zone="sql-discard">
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<primary>DISCARD</primary>
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</indexterm>
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<refsynopsisdiv>
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<synopsis>
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DISCARD { ALL | PLANS | TEMPORARY | TEMP }
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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>DISCARD</> releases internal resources associated with a
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database session. These resources are normally released at the end
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of the session.
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</para>
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<para>
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<command>DISCARD TEMP</> drops all temporary tables created in the
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current session. <command>DISCARD PLANS</> releases all internally
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cached query plans. <command>DISCARD ALL</> resets a session to
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its original state, discarding temporary resources and resetting
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session-local configuration changes.
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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><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
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<listitem>
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<para>
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Drops all temporary tables created in the current session.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>PLANS</literal></term>
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<listitem>
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<para>
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Releases all cached query plans.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>ALL</literal></term>
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<listitem>
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<para>
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Releases all temporary resources associated with the current
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session and resets the session to its initial state. This has
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the same effect as executing the following sequence of
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statements:
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<programlisting>
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SET SESSION AUTHORIZATION DEFAULT;
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RESET ALL;
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DEALLOCATE ALL;
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CLOSE ALL;
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UNLISTEN *;
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DISCARD PLANS;
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DISCARD TEMP;
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</programlisting>
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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>DISCARD ALL</> cannot be executed inside a transaction block.
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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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<command>DISCARD</command> is a <productname>PostgreSQL</productname> extension.
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</para>
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</refsect1>
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</refentry>
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