In temporal databases, decision time is the time when a decision was made about a fact stored in a database.[citation needed] It is used to keep a history of decisions about valid times.
In a database table, the start and end time of the decision time interval can be represented by adding two table columns. This interval is closed [ in the lower bound, and open at the upper bound ). When a decision has not been replaced, the end time of the decision is unknown, and it can thus be considered valid "until changed" or infinite (∞).
Valid time and decision time are ways of modeling data, and is not applicable for all types of data,[1] and transaction time is hence the most used temporal functionality.[1] The concept of decision time can for example be used in bitemporal databases (together with valid time instead of transaction time), or in tritemporal databases.[2]