'\" t
.\"     Title: DROP INDEX
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.75.2 <http://docbook.sf.net/>
.\"      Date: 2016
.\"    Manual: PostgreSQL 9.5.2 Documentation
.\"    Source: PostgreSQL 9.5.2
.\"  Language: English
.\"
.TH "DROP INDEX" "5sql" "2016" "PostgreSQL 9.5.2" "PostgreSQL 9.5.2 Documentation"
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.SH "NAME"
DROP_INDEX \- remove an index
.SH "SYNOPSIS"
.sp
.nf
DROP INDEX [ CONCURRENTLY ] [ IF EXISTS ] \fIname\fR [, \&.\&.\&.] [ CASCADE | RESTRICT ]
.fi
.SH "DESCRIPTION"
.PP

\fBDROP INDEX\fR
drops an existing index from the database system\&. To execute this command you must be the owner of the index\&.
.SH "PARAMETERS"
.PP
CONCURRENTLY
.RS 4
Drop the index without locking out concurrent selects, inserts, updates, and deletes on the index\(aqs table\&. A normal
\fBDROP INDEX\fR
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\&.
.sp
There are several caveats to be aware of when using this option\&. Only one index name can be specified, and the
CASCADE
option is not supported\&. (Thus, an index that supports a
UNIQUE
or
PRIMARY KEY
constraint cannot be dropped this way\&.) Also, regular
\fBDROP INDEX\fR
commands can be performed within a transaction block, but
\fBDROP INDEX CONCURRENTLY\fR
cannot\&.
.RE
.PP
IF EXISTS
.RS 4
Do not throw an error if the index does not exist\&. A notice is issued in this case\&.
.RE
.PP
\fIname\fR
.RS 4
The name (optionally schema\-qualified) of an index to remove\&.
.RE
.PP
CASCADE
.RS 4
Automatically drop objects that depend on the index\&.
.RE
.PP
RESTRICT
.RS 4
Refuse to drop the index if any objects depend on it\&. This is the default\&.
.RE
.SH "EXAMPLES"
.PP
This command will remove the index
title_idx:
.sp
.if n \{\
.RS 4
.\}
.nf
DROP INDEX title_idx;
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP

\fBDROP INDEX\fR
is a
PostgreSQL
language extension\&. There are no provisions for indexes in the SQL standard\&.
.SH "SEE ALSO"
CREATE INDEX (\fBCREATE_INDEX\fR(5))