DROP CONVERSION removes a previously defined conversion.
To be able to drop a conversion, you must own the conversion.
The name of the conversion. The conversion name may be schema-qualified.
These key words do not have any effect, since there are no dependencies on conversions.
Use CREATE CONVERSION to create user-defined conversions.
The privileges required to drop a conversion may be changed in a future release.
DROP CONVERSION is a PostgreSQL extension. There is no DROP CONVERSION statement in SQL99.