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bb4eefe7bf
DocBook XML is superficially compatible with DocBook SGML but has a slightly stricter DTD that we have been violating in a few cases. Although XSLT doesn't care whether the document is valid, the style sheets don't necessarily process invalid documents correctly, so we need to work toward fixing this. This first commit moves the indexterms in refentry elements to an allowed position. It has no impact on the output.
134 lines
3.3 KiB
Plaintext
134 lines
3.3 KiB
Plaintext
<!--
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doc/src/sgml/ref/drop_index.sgml
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PostgreSQL documentation
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-->
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<refentry id="SQL-DROPINDEX">
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<indexterm zone="sql-dropindex">
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<primary>DROP INDEX</primary>
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</indexterm>
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<refmeta>
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<refentrytitle>DROP INDEX</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>DROP INDEX</refname>
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<refpurpose>remove an index</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<synopsis>
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DROP INDEX [ CONCURRENTLY ] [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
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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>DROP INDEX</command> drops an existing index from the database
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system. To execute this command you must be the owner of
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the index.
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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>CONCURRENTLY</literal></term>
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<listitem>
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<para>
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Drop the index without locking out concurrent selects, inserts, updates,
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and deletes on the index's table. A normal <command>DROP INDEX</>
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acquires exclusive lock on the table, blocking other accesses until the
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index drop can be completed. With this option, the command instead
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waits until conflicting transactions have completed.
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</para>
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<para>
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There are several caveats to be aware of when using this option.
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Only one index name can be specified, and the <literal>CASCADE</> option
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is not supported. (Thus, an index that supports a <literal>UNIQUE</> or
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<literal>PRIMARY KEY</> constraint cannot be dropped this way.)
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Also, regular <command>DROP INDEX</> commands can be
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performed within a transaction block, but
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<command>DROP INDEX CONCURRENTLY</> cannot.
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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>IF EXISTS</literal></term>
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<listitem>
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<para>
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Do not throw an error if the index does not exist. A notice is issued
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in this case.
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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><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 an index to remove.
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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>CASCADE</literal></term>
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<listitem>
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<para>
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Automatically drop objects that depend on the index.
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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>RESTRICT</literal></term>
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<listitem>
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<para>
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Refuse to drop the index if any objects depend on it. This is
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the default.
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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>Examples</title>
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<para>
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This command will remove the index <literal>title_idx</literal>:
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<programlisting>
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DROP INDEX title_idx;
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</programlisting></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>DROP INDEX</command> is a
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<productname>PostgreSQL</productname> language extension. There
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are no provisions for indexes in the SQL standard.
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</para>
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</refsect1>
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<refsect1>
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<title>See Also</title>
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<simplelist type="inline">
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<member><xref linkend="sql-createindex"></member>
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</simplelist>
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</refsect1>
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</refentry>
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