drop_index (7) - Linux Manuals

drop_index: remove an index

Command to display drop_index manual in Linux: $ man 7 drop_index

DROP INDEX - remove an index

DROP INDEX [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]

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

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.

This command will remove the index title_idx:

DROP INDEX title_idx;

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