centos man page for drop_index

DROP 
INDEX(7)						  PostgreSQL 9.2.7 Documentation					     DROP INDEX(7)

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
       CONCURRENTLY
	   Drop the index without locking out concurrent selects, inserts, updates, and deletes on the index's table. A normal DROP INDEX 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.

	   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.

       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.

       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 (CREATE_INDEX(7))

PostgreSQL 9.2.7						    2014-02-17							     DROP INDEX(7)