pg_transform — PostgreSQL system catalog

The PostgreSQL pg_transform system catalog: full column reference (names, types, descriptions), catalog relationships and version support.

The Sev-1 Admin
The Sev-1 Admin  ·  2 min read

Summary

The catalog pg_transform stores information about transforms, which are a mechanism to adapt data types to procedural languages. See createtransform for more information.

(Description quoted from the official PostgreSQL documentation.)

Columns

The pg_transform system catalog exposes the following columns (names, types and descriptions are taken verbatim from the PostgreSQL documentation):

  • 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 the default behavior should be used.
  • 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 the default behavior should be used.

Related catalogs

This object references the following other system catalogs:

Version applicability

Present in PostgreSQL 17, 18, 19 (verified against each release’s documentation). This is a long-standing system object that also exists in earlier PostgreSQL releases.

Related & references

Reference: PostgreSQL documentation — pg_transform.