- All new rows that have transaction-time columns are assigned transaction-time periods with end bounds of UNTIL_CLOSED. UNTIL_CLOSED is only associated with transaction-time columns.
- New rows that have valid-time columns can be assigned valid-time periods with end bounds of UNTIL_CHANGED to represent that the information in the row is valid indefinitely.
UNTIL_CLOSED has a data type of TIMESTAMP(6) WITH TIME ZONE and a value of TIMESTAMP '9999-12-31 23:59:59.999999+00:00'.
The value of UNTIL_CHANGED depends on the data type and precision of the valid-time column. If the type is PERIOD(DATE), UNTIL_CHANGED is the value DATE '9999-12-31'. If the type is PERIOD(TIMESTAMP), UNTIL_CHANGED is the value of TIMESTAMP '9999-12-31 23:59:59.999999+00:00', with precision and time zone matching that specified for the valid-time data type.
For more information on UNTIL_CHANGED and UNTIL_CLOSED, see the discussion of Period data types in Teradata Vantage™ - Data Types and Literals, B035-1143.