pg_description
pg_description
is a system catalogue table storing comments for database objects.
pg_description
was added in PostgreSQL 6.3.
Purpose
pg_description
stores arbitrary user-defined descriptions for objects in the current database defined by the COMMENT ON
command.
For comments on global objects (roles, tablespaces etc.), see pg_shdescription
.
Definition by PostgreSQL version
pg_description (PostgreSQL 15)
Table "pg_catalog.pg_description" Column | Type | Collation | Nullable | Default -------------+---------+-----------+----------+--------- objoid | oid | | not null | classoid | oid | | not null | objsubid | integer | | not null | description | text | C | not null | Indexes: "pg_description_o_c_o_index" PRIMARY KEY, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 14)
Table "pg_catalog.pg_description" Column | Type | Collation | Nullable | Default -------------+---------+-----------+----------+--------- objoid | oid | | not null | classoid | oid | | not null | objsubid | integer | | not null | description | text | C | not null | Indexes: "pg_description_o_c_o_index" PRIMARY KEY, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 13)
Table "pg_catalog.pg_description" Column | Type | Collation | Nullable | Default -------------+---------+-----------+----------+--------- objoid | oid | | not null | classoid | oid | | not null | objsubid | integer | | not null | description | text | C | not null | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 12)
Table "pg_catalog.pg_description" Column | Type | Collation | Nullable | Default -------------+---------+-----------+----------+--------- objoid | oid | | not null | classoid | oid | | not null | objsubid | integer | | not null | description | text | C | not null | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 11)
Table "pg_catalog.pg_description" Column | Type | Collation | Nullable | Default -------------+---------+-----------+----------+--------- objoid | oid | | not null | classoid | oid | | not null | objsubid | integer | | not null | description | text | | not null | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 10)
Table "pg_catalog.pg_description" Column | Type | Collation | Nullable | Default -------------+---------+-----------+----------+--------- objoid | oid | | not null | classoid | oid | | not null | objsubid | integer | | not null | description | text | | not null | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.6)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | not null Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.5)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | not null Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.4)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.3)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.2)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.1)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 9.0)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 8.4)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 8.3)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
pg_description (PostgreSQL 8.2)
Table "pg_catalog.pg_description" Column | Type | Modifiers -------------+---------+----------- objoid | oid | not null classoid | oid | not null objsubid | integer | not null description | text | Indexes: "pg_description_o_c_o_index" UNIQUE, btree (objoid, classoid, objsubid)
Documentation: pg_description
Change history
- PostgreSQL 9.5
- column
description
set toNOT NULL
(commit 82a532b3)
- column
- PostgreSQL 7.2
- following columns added (commit bf56f075):
classoid
objsubid
- following columns added (commit bf56f075):
- PostgreSQL 6.3
- added (commit 5071ae29)
Examples
Add a comment to a table:
postgres=# COMMENT ON TABLE foo IS 'Store all the things'; COMMENT postgres=# SELECT * FROM pg_description WHERE objoid = 'foo'::REGCLASS; objoid | classoid | objsubid | description --------+----------+----------+---------------------- 16470 | 1259 | 0 | Store all the things (1 row)
Remove a comment from a table:
postgres=# COMMENT ON TABLE foo IS NULL; COMMENT postgres=# SELECT * FROM pg_description WHERE objoid = 'foo'::REGCLASS; objoid | classoid | objsubid | description --------+----------+----------+------------- (0 rows)
References
- PostgreSQL documentation: pg_description