pg_extension
   The catalog pg_extension stores information
   about the installed extensions.  See Section 38.17
   for details about extensions.
  
Table 53.22. pg_extension Columns
| Column Type Description | 
|---|
| 
        Row identifier | 
| 
        Name of the extension | 
| 
        Owner of the extension | 
| 
        Schema containing the extension's exported objects | 
| 
        True if extension can be relocated to another schema | 
| 
        Version name for the extension | 
| 
        
       Array of  | 
| 
        
       Array of  | 
   Note that unlike most catalogs with a “namespace” column,
   extnamespace is not meant to imply
   that the extension belongs to that schema.  Extension names are never
   schema-qualified.  Rather, extnamespace
   indicates the schema that contains most or all of the extension's
   objects.  If extrelocatable is true, then
   this schema must in fact contain all schema-qualifiable objects
   belonging to the extension.