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>DROP INDEX</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN73908"
></A
><H2
>Name</H2
>DROP INDEX -- remove an index</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN73913"
></A
><H2
>Synopsis</H2
><PRE
CLASS="SYNOPSIS"
>DROP INDEX [ CONCURRENTLY ] [ IF EXISTS ] <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
> [, ...] [ CASCADE | RESTRICT ]</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73916"
></A
><H2
>Description</H2
><P
> <TT
CLASS="COMMAND"
>DROP INDEX</TT
> drops an existing index from the database
system. To execute this command you must be the owner of
the index.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73920"
></A
><H2
>Parameters</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>CONCURRENTLY</TT
></DT
><DD
><P
> Drop the index without locking out concurrent selects, inserts, updates,
and deletes on the index's table. A normal <TT
CLASS="COMMAND"
>DROP INDEX</TT
>
acquires exclusive lock on the table, blocking other accesses until the
index drop can be completed. With this option, the command instead
waits until conflicting transactions have completed.
</P
><P
> There are several caveats to be aware of when using this option.
Only one index name can be specified, and the <TT
CLASS="LITERAL"
>CASCADE</TT
> option
is not supported. (Thus, an index that supports a <TT
CLASS="LITERAL"
>UNIQUE</TT
> or
<TT
CLASS="LITERAL"
>PRIMARY KEY</TT
> constraint cannot be dropped this way.)
Also, regular <TT
CLASS="COMMAND"
>DROP INDEX</TT
> commands can be
performed within a transaction block, but
<TT
CLASS="COMMAND"
>DROP INDEX CONCURRENTLY</TT
> cannot.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>IF EXISTS</TT
></DT
><DD
><P
> Do not throw an error if the index does not exist. A notice is issued
in this case.
</P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
></DT
><DD
><P
> The name (optionally schema-qualified) of an index to remove.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>CASCADE</TT
></DT
><DD
><P
> Automatically drop objects that depend on the index.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>RESTRICT</TT
></DT
><DD
><P
> Refuse to drop the index if any objects depend on it. This is
the default.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73955"
></A
><H2
>Examples</H2
><P
> This command will remove the index <TT
CLASS="LITERAL"
>title_idx</TT
>:
</P><PRE
CLASS="PROGRAMLISTING"
>DROP INDEX title_idx;</PRE
><P></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73960"
></A
><H2
>Compatibility</H2
><P
> <TT
CLASS="COMMAND"
>DROP INDEX</TT
> is a
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> language extension. There
are no provisions for indexes in the SQL standard.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73965"
></A
><H2
>See Also</H2
><A
HREF="sql-createindex.html"
>CREATE INDEX</A
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