Documentation / Object Identifier Types
PostgreSQL Object Identifier Types
Object identifiers, reg* name aliases, and the transaction, command and row identifiers documented alongside them.
Reading PostgreSQL 18.6.
18 entries; 16 recorded in PostgreSQL 18.6.
| Name and purpose | Group | Version history |
|---|---|---|
| oidoid numeric object identifier. |
Object identifiers | |
| oid8oid8 Not recorded in the selected version. |
Object identifiersNot recorded | |
| regclassregclass relation name. |
Object name aliases | |
| regcollationregcollation collation name. |
Object name aliases | |
| regconfigregconfig text search configuration. |
Object name aliases | |
| regdatabaseregdatabase Not recorded in the selected version. |
Object name aliasesNot recorded | |
| regdictionaryregdictionary text search dictionary. |
Object name aliases | |
| regnamespaceregnamespace namespace name. |
Object name aliases | |
| regoperregoper operator name. |
Object name aliases | |
| regoperatorregoperator operator with argument types. |
Object name aliases | |
| regprocregproc function name. |
Object name aliases | |
| regprocedureregprocedure function with argument types. |
Object name aliases | |
| regroleregrole role name. |
Object name aliases | |
| regtyperegtype data type name. |
Object name aliases | |
| cidcid A third identifier type used by the system is cid , or command identifier. This is the data type of the system columns cmin and cmax . Command identifiers are also 32-bit quantities. |
Transaction and row identifiers | |
| tidtid A final identifier type used by the system is tid , or tuple identifier (row identifier). This is the data type of the system column ctid . A tuple ID is a pair (block number, tuple index within block) that identifies the physical location of the row within its table. |
Transaction and row identifiers | |
| xidxid Another identifier type used by the system is xid , or transaction (abbreviated xact ) identifier. This is the data type of the system columns xmin and xmax . Transaction identifiers are 32-bit quantities. In some contexts, a 64-bit variant xid8 is used. Unlike xid values, xid8 values increase strictly monotonically and cannot be reused in the lifetime of a database cluster. See Section 67.1 for more details. |
Transaction and row identifiers | |
| xid8xid8 Another identifier type used by the system is xid , or transaction (abbreviated xact ) identifier. This is the data type of the system columns xmin and xmax . Transaction identifiers are 32-bit quantities. In some contexts, a 64-bit variant xid8 is used. Unlike xid values, xid8 values increase strictly monotonically and cannot be reused in the lifetime of a database cluster. See Section 67.1 for more details. |
Transaction and row identifiers |
RecordedFirst recordedInterface or attribute changeNo longer recorded
Squares indicate presence in sampled builds, not first introduction. Select a square for the same-version definition and sources.
Reading this collection
Name aliases resolve catalog objects. Bare OIDs are not persistent identities across databases or clusters; transaction identifiers and physical row locations have different lifetimes.