DROP INDEX

DROP INDEX

7

SQL - Language Statements

DROP INDEX

remove an index

DROP INDEX \[ CONCURRENTLY \] \[ IF EXISTS \]

name

\[, \...\] \[ CASCADE \| RESTRICT \]

Description
===========

`DROP INDEX` drops an existing index from the database system. To
execute this command you must be the owner of the index.

Parameters
==========

`CONCURRENTLY`

:   Drop the index without locking out concurrent selects, inserts,
    updates, and deletes on the index\'s table. A normal `DROP INDEX`
    acquires an `ACCESS 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.

    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
    `DROP INDEX` commands can be performed within a transaction block,
    but `DROP INDEX CONCURRENTLY` cannot. Lastly, indexes on partitioned
    tables cannot be dropped using this option.

    For temporary tables, `DROP INDEX` is always non-concurrent, as no
    other session can access them, and non-concurrent index drop is
    cheaper.

`IF EXISTS`

:   Do not throw an error if the index does not exist. A notice is
    issued in this case.

name

:   The name (optionally schema-qualified) of an index to remove.

`CASCADE`

:   Automatically drop objects that depend on the index, and in turn all
    objects that depend on those objects (see [???](#ddl-depend)).

`RESTRICT`

:   Refuse to drop the index if any objects depend on it. This is the
    default.

Examples
========

This command will remove the index `title_idx`:

    DROP INDEX title_idx;

Compatibility
=============

`DROP INDEX` is a PostgreSQL language extension. There are no provisions
for indexes in the SQL standard.

See Also
========
