PostgreSQL 9.2.1 Documentation
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# DROP INDEX

## Name

DROP INDEX -- remove an index

## Synopsis

    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

`IF EXISTS`

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

`CONCURRENTLY`

  When this option is used, PostgreSQL will drop the index without taking any locks that prevent concurrent selects, inserts, updates, or deletes on the table; whereas a standard index drop waits for a lock that locks out everything on the table until it's done. Concurrent drop index is a two stage process. First, we mark the index both invalid and not ready then commit the change. Next we wait until there are no users locking the table who can see the index.

  There are several caveats to be aware of when using this option. Only one index name can be specified if the `CONCURRENTLY` parameter is specified. Regular `DROP INDEX` command can be performed within a transaction block, but `DROP INDEX CONCURRENTLY` cannot. The CASCADE option is not supported when dropping an index concurrently.

`name`

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

`CASCADE`

  Automatically drop objects that depend on the index.

`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

CREATE INDEX

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