The pg_description system catalog table stores optional descriptions (comments) for each database object. Descriptions can be manipulated with the COMMENT command and viewed with psql's \d meta-commands. Descriptions of many built-in system objects are provided in the initial contents of pg_description. See also pg_shdescription, which performs a similar function for descriptions involving objects that are shared across a Greenplum system.
|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|
|objsubid||int4||For a comment on a table column, this is the column number. For all other object types, this column is zero.|
|description||text||Arbitrary text that serves as the description of this object.|