DROP COLLATION — remove a collation
DROP COLLATION [ IF EXISTS ] name [ CASCADE | RESTRICT ]DROP COLLATION removes a previously defined collation. To be able to drop a collation, you must own the collation.
IF EXISTSDo not throw an error if the collation does not exist. A notice is issued in this case.
nameThe name of the collation. The collation name can be schema-qualified.
CASCADEAutomatically drop objects that depend on the collation, and in turn all objects that depend on those objects (see Section 5.13).
RESTRICTRefuse to drop the collation if any objects depend on it. This is the default.
To drop the collation named german:
DROP COLLATION german;
The DROP COLLATION command conforms to the SQL standard, apart from the IF EXISTS option, which is a PostgreSQL extension.