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, Teradata 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” on page 20.