Bitemporal algebras; Historical algebras; Transaction-time algebras; Valid-time algebras
Temporal algebra is a generic term for an algebra defined for a data model that organizes temporal data. A temporal data model may support valid-time (the time over which a data value is valid), transaction-time (time when a data value is recorded in the database), or both (bitemporal). So an algebra can be defined for each case, a valid-time relational algebra, a transaction-time relational algebra, or a bitemporal relational algebra, respectively. For the relational data model, temporal algebras include the temporal versions of relational algebra operations in addition to new operations for manipulating temporal data like time-slice, rollback, temporal coalesce, temporal restructuring operations, and others. For a temporal algebra, it is desirable to be closed (common algebras are closed), a consistent extension of the relational algebra, and to reduce to relational algebra...
- 2.Böhlen MH, Snodgrass RT, Soo MD. Coalescing in temporal databases. In: Proceedings of the 22nd International Conference on Very Large Data Bases; 1996. p. 180–91.Google Scholar
- 3.Clifford J, Croker A. The historical relational data model (HRDM) and algebra based on lifespans. In: Proceedings of the 3rd International Conference on Data Engineering; 1987. p. 528–37.Google Scholar
- 17.Tuzhilin A, Clifford J. A temporal relational algebra as basis for temporal relational completeness. In: Proceedings of the 16th International Conference on Very Large Data Bases; 1990. p. 13–23.Google Scholar