DROP INDEX
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 normalDROP 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 theCASCADE option is not supported. (Thus, an index that supports aUNIQUE orPRIMARY KEY constraint cannot be dropped this way.) Also, regularDROP INDEX commands can be performed within a transaction block, butDROP 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.