Because temporal tables track information in a time-aware fashion, any new information inserted into temporal tables must be associated with at least one time period: the system time or valid time. Rows in bitemporal tables include both kinds of time periods.
- When you insert a row into a system-time table, the database manages the system-time period for you. The start of the system-time period is automatically set to the time the row was inserted into the table, and the end of the system-time period is set to UNTIL-CLOSED. The row is considered open and actively participates in SQL operations until the row is deleted or until a modification to the row causes the original information to become obsolete.
- When you insert a row into a valid-time table, you must specify the start and end of the valid-time period for the row, the period for which the information in the row is in effect. This could be a period in the past, one that includes the current time, or can be a period in the future. The valid-time period can span from history to future times. If you are inserting a row containing information that is valid indefinitely, set the end value of the valid-time period to UNTIL_CHANGED.
For more information about inserting rows into temporal tables, see Modifying Temporal Tables.