51.56. pg_transform
  The catalog
  
   pg_transform
  
  stores information about
   transforms, which are a mechanism to adapt data types to procedural
   languages.  See
  
   
    CREATE TRANSFORM
   
  
  for more information.
 
   
    Table 51.56. 
    
     pg_transform
    
    Columns
   
  
| Name | Type | References | Description | 
|---|---|---|---|
| 
        trftype
        | 
        oid
        | 
        
          | OID of the data type this transform is for | 
| 
        trflang
        | 
        oid
        | 
        
          | OID of the language this transform is for | 
| 
        trffromsql
        | 
        regproc
        | 
        
          | The OID of the function to use when converting the data type for input to the procedural language (e.g., function parameters). Zero is stored if this operation is not supported. | 
| 
        trftosql
        | 
        regproc
        | 
        
          | The OID of the function to use when converting output from the procedural language (e.g., return values) to the data type. Zero is stored if this operation is not supported. |