pg_shdescription
A system table recording comments for shared database objects
pg_shdescription is a system catalogue table recording comments for shared database objects
pg_shdescription was added in PostgreSQL 8.2.
This table is shared across all databases in a cluster.
Definition by PostgreSQL version
pg_shdescription (PostgreSQL 14)
Table "pg_catalog.pg_shdescription"
Column | Type | Collation | Nullable | Default
-------------+------+-----------+----------+---------
objoid | oid | | not null |
classoid | oid | | not null |
description | text | C | not null |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 13)
Table "pg_catalog.pg_shdescription"
Column | Type | Collation | Nullable | Default
-------------+------+-----------+----------+---------
objoid | oid | | not null |
classoid | oid | | not null |
description | text | C | not null |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 12)
Table "pg_catalog.pg_shdescription"
Column | Type | Collation | Nullable | Default
-------------+------+-----------+----------+---------
objoid | oid | | not null |
classoid | oid | | not null |
description | text | C | not null |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 11)
Table "pg_catalog.pg_shdescription"
Column | Type | Collation | Nullable | Default
-------------+------+-----------+----------+---------
objoid | oid | | not null |
classoid | oid | | not null |
description | text | | not null |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 10)
Table "pg_catalog.pg_shdescription"
Column | Type | Collation | Nullable | Default
-------------+------+-----------+----------+---------
objoid | oid | | not null |
classoid | oid | | not null |
description | text | | not null |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.6)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text | not null
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.5)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text | not null
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.4)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.3)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.2)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.1)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 9.0)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 8.4)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 8.3)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
pg_shdescription (PostgreSQL 8.2)
Table "pg_catalog.pg_shdescription"
Column | Type | Modifiers
-------------+------+-----------
objoid | oid | not null
classoid | oid | not null
description | text |
Indexes:
"pg_shdescription_o_c_index" UNIQUE, btree (objoid, classoid), tablespace "pg_global"
Tablespace: "pg_global"
Documentation: pg_shdescription
Change history
This table has remained unchanged since its introduction in PostgreSQL 8.2.
Examples
Add a comment to a tablespace:
postgres=# COMMENT ON TABLESPACE tblspc_1 IS 'Store some of the things'; COMMENT postgres=# SELECT * FROM pg_shdescription WHERE objoid = (SELECT oid FROM pg_tablespace WHERE spcname = 'tblspc_1'); objoid | classoid | description --------+----------+-------------------------- 16385 | 1213 | Store some of the things (1 row)
Remove a comment from a tablespace:
postgres=# COMMENT ON TABLESPACE space_1 IS NULL; COMMENT postgres=# SELECT * FROM pg_shdescription WHERE objoid = (SELECT oid FROM pg_tablespace WHERE spcname = 'tblspc_1'); objoid | classoid | description --------+----------+------------- (0 rows)
References
- PostgreSQL documentation: pg_shdescription