SYSTEM CATALOG · System catalog

pg_shdepend

PostgreSQL documentation ↗Source definition ↗

The catalog pg_shdepend records the dependency relationships between database objects and shared objects, such as roles. This information allows PostgreSQL to ensure that those objects are unreferenced before attempting to delete them. See also pg_depend, which performs a similar function for dependencies involving objects within a single database. Unlike most system catalogs, pg_shdepend is shared across all databases of a cluster: there is only one copy of pg_shdepend per cluster, not one per database.

First seen PG 9.0Last seen PG 19Columns 7

9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19^β3

Checked column by column against a PostgreSQL 18.6 instance · Raw measurement record ↗

Columns PostgreSQL 18

pg_shdepend

COLUMN	TYPE	DESCRIPTION
`dbid`	`oid`NOT NULL	The OID of the database the dependent object is in, or zero for a shared objectReferences:`pg_database.oid`
`classid`	`oid`NOT NULL	The OID of the system catalog the dependent object is inReferences:`pg_class.oid`
`objid`	`oid`NOT NULL	The OID of the specific dependent objectReferences:`any OID column`
`objsubid`	`integer`NOT NULLDocumented as:`int4`	For a table column, this is the column number (the objid and classid refer to the table itself). For all other object types, this column is zero.
`refclassid`	`oid`NOT NULL	The OID of the system catalog the referenced object is in (must be a shared catalog)References:`pg_class.oid`
`refobjid`	`oid`NOT NULL	The OID of the specific referenced objectReferences:`any OID column`
`deptype`	`"char"`NOT NULLDocumented as:`char`	A code defining the specific semantics of this dependency relationship; see text

Columns marked "implicit" are not included in SELECT *; some early statistics views are completed from same-version source, and the extra provenance is shown in the column description.

Common system columns 6

System attributes PostgreSQL provides, normally not expanded by SELECT *. Kept separately so they are not mixed in with ordinary columns.

Columns	Type	attnum
`tableoid`	`oid`	-6
`cmax`	`cid`	-5
`xmax`	`xid`	-4
`cmin`	`cid`	-3
`xmin`	`xid`	-2
`ctid`	`tid`	-1

Column evolution matrix

Hover a cell for the column type

PresentAdded / type or attribute changeRemoved

COLUMN	9.0	9.1	9.2	9.3	9.4	9.5	9.6	10	11	12	13	14	15	16	17	18	19
`dbid`
`classid`
`objid`
`objsubid`
`refclassid`
`refobjid`
`deptype`

9.0 is the coverage baseline; a column already present in the baseline is not marked as added. The matrix aligns columns by name, so a rename appears as the old column removed and a new column added.

Evolution timeline

Changes between adjacent majors

PostgreSQL 15 ← 14

3 column description updates

PostgreSQL 14 ← 13

3 column description updates

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