pg_conversion
   The catalog pg_conversion describes
   encoding conversion functions.  See CREATE CONVERSION
   for more information.
  
Table 52.14. pg_conversion Columns
Column Type Description  | 
|---|
        Row identifier  | 
        Conversion name (unique within a namespace)  | 
        The OID of the namespace that contains this conversion  | 
        Owner of the conversion  | 
        Source encoding ID  | 
        Destination encoding ID  | 
        Conversion function  | 
        True if this is the default conversion  |