| 摘要 |
Computer programs embodied in computer-readable media that can use canonical schemas to persist data from non-temporal tables, effective-time tables, assertion-time tables, and bitemporal tables, and that can enforce temporal integrity constraints on those tables, are provided. In one embodiment, the canonical schemas are used by database tables. In another embodiment, they are used by the physical files which persist data from those tables. Temporal metadata is used to express temporal requirements. Thus, uni-temporal, bitemporal, and temporally-enabled non-temporal tables can be generated without altering existing data models or designing temporal features into new data models. Support is also provided for managing temporal data that exists in future assertion time, and for using episodes to enforce temporal referential integrity. |
