## 51.55. `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 51.55. `pg_transform` Columns

Column Type Description
`oid` `oid` Row identifier
`trftype` `oid` (references `pg_type`.`oid`) OID of the data type this transform is for
`trflang` `oid` (references `pg_language`.`oid`) OID of the language this transform is for
`trffromsql` `regproc` (references `pg_proc`.`oid`) 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` (references `pg_proc`.`oid`) 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.