DROP CAST
Description
DROP CAST removes a previously defined cast.
To be able to drop a cast, you must own the source or the target data type. These are the same privileges that are required to create a cast.
Parameters
- IF EXISTS
 - 
    
Do not throw an error if the cast does not exist. A notice is issued in this case.
 - source_type
 - 
    
The name of the source data type of the cast.
 - target_type
 - 
    
The name of the target data type of the cast.
 - 
    
     CASCADE
    
    
RESTRICT - 
    
These key words do not have any effect, since there are no dependencies on casts.