pg_shdescription

The pg_shdescription system catalog table stores optional descriptions (comments) for shared database objects. Descriptions can be manipulated with the COMMENT command and viewed with psql's \d meta-commands. See also pg_description, which performs a similar function for descriptions involving objects within a single database. Unlike most system catalogs, pg_shdescription is shared across all databases of a Greenplum system: there is only one copy of pg_shdescription per system, not one per database.

column	type	references	description
objoid	oid	any OID column	The OID of the object this description pertains to.
classoid	oid	pg_class.oid	The OID of the system catalog this object appears in
description	text		Arbitrary text that serves as the description of this object.

Parent topic: System Catalogs Definitions