validtime

Validtime, in database and information modeling, refers to the temporal dimension that records when a fact is true in the real world. It represents the period during which a statement or data item is valid, regardless of when it is stored or observed. This is distinct from transaction time, which tracks when a fact was stored or observed by the database system.

A validtime value is typically an interval with a start and end timestamp. Intervals can be closed or open-ended, and end points may sometimes be infinite to denote ongoing validity. In many implementations, validtime is modeled with two columns (valid_from and valid_to) or with a dedicated period data type, and may be used in combination with transaction time to support bi-temporal databases.

Bi-temporal databases retain both validtime and transaction time, enabling queries about what was true in the real world at a given date, what the database believed at a given time, and how data changed over time. This supports historical analysis, auditing, and regulatory compliance.

Common use cases include tracking address histories, product availability, or any domain where facts evolve over time. Typical queries involve retrieving the fact valid at a specific date, consolidating overlapping intervals, or projecting the most recent valid record for each entity.

Standards and implementations vary. SQL-based systems have introduced temporal features to support validtime, including period semantics and temporal predicates. Practical considerations include handling overlapping intervals, time zones, and performance when indexing temporal data.