pg_transform

The pg_transform catalog provides information about data type transforms.

Column name Data type Description
oid oid A unique row identifier.
trftype oid (references pg_type.oid) The OID of the data type for which this transform is defined.
trflang oid (references pg_language.oid) The OID of the procedural language for which this transform is defined.
trffromsql regproc (references pg_proc.oid) The OID of the function used to convert the data type for input into the procedural language. For example, function parameters.
0 – The default behavior is used.
trftosql regproc (references pg_proc.oid) The OID of the function used to convert output from the procedural language (e.g., return values) back into the data type.
0 – The default behavior is used.