In addition to the regular rules for use of derived period columns with SELECT described in Teradata Vantage™ - SQL Data Manipulation Language, B035-1146, the following rules and restrictions apply to the use of derived VALIDTIME and TRANSACTIONTIME columns in temporal tables.
- Component columns of derived VALIDTIME and TRANSACTIONTIME columns are not projected for CURRENT and SEQUENCED SELECT * requests.
- Component columns of derived VALIDTIME and TRANSACTIONTIME columns are projected for NONSEQUENCED SELECT * requests.
- The system generated VALIDTIME column that is projected for a SEQUENCED VALIDTIME query will be a true period data type column, even if the valid-time column of the queried table is a derived period column.