DROP INDEX — remove an index
DROP INDEX [ CONCURRENTLY ] [ 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.
CONCURRENTLY
Drop the index without locking out concurrent selects, inserts, updates,
and deletes on the index's table. A normal DROP INDEX
acquires an ACCESS 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.
Lastly, indexes on partitioned tables cannot be dropped using this
option.
For temporary tables, DROP INDEX is always
non-concurrent, as no other session can access them, and
non-concurrent index drop is cheaper.
IF EXISTSDo not throw an error if the index does not exist. A notice is issued in this case.
nameThe name (optionally schema-qualified) of an index to remove.
CASCADEAutomatically drop objects that depend on the index, and in turn all objects that depend on those objects (see Section 5.14).
RESTRICTRefuse 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
LightDB language extension. There
are no provisions for indexes in the SQL standard.