pg_transform stores information about transforms, which are a mechanism to adapt data types to procedural languages. See CREATE TRANSFORM for more information.
|OID of the data type this transform is for|
|OID of the language this transform is for|
|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.|
|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.|