Documentation / Object Identifier Types / Transaction and row identifiers
xid
xid
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.
Reading PostgreSQL 18.6.
Description
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.
- System columns
- xmin, xmax
Related entries
Documentation and source
Source build
- Version
- 18.6
- Build
- PostgreSQL 18.6 Documentation
- Source fingerprint
8b3360302225f08ae72716ce1804596de95b568e5d31f788cb4597427b28cc38
Related entries
Back to Object Identifier Types · Recorded in PostgreSQL 10 through 20; the first sample is not necessarily its introduction.