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)