This method:
- requires that the executor have the NONTEMPORAL privilege in the database, and that the database be enabled to recognize that privilege. For more information on the NONTEMPORAL privilege, see Teradata Vantage™ - Temporal Table Support, B035-1182.
- cannot be used if the transaction-time table is row partitioned on the beginning or ending bound of the transaction-time.
- Note all the constraints on the transaction-time table.
- Drop all the constraints from the transaction-time table.
- Use NONTEMPORAL ALTER TABLE to drop the existing transaction-time column. Use the WITHOUT DELETE option to preserve the historical closed rows, which would otherwise be deleted automatically when you drop the transaction-time column:
ALTER TABLE transaction_time_table_name DROP transaction_time_column WITHOUT DELETE
- Use ALTER TABLE to create the SYSTEM_TIME derived period column and to add attributes to the set the sys_start and sys_end columns in the same ALTER TABLE statement:
ALTER TABLE new_table_name ADD PERIOD FOR SYSTEM_TIME(sys_start,sys_end) ADD sys_start TIMESTAMP(6) WITH TIME ZONE NOT NULL GENERATED ALWAYS AS ROW START ADD sys_end TIMESTAMP(6) WITH TIME ZONE NOT NULL GENERATED ALWAYS AS ROW END; - Add system versioning to make the new table an ANSI system-time temporal table:
ALTER TABLE new_table_name ADD SYSTEM VERSIONING; - Recreate all the constraints that were dropped in step 2. Note that ANSI constraints behave as NONSEQUENCED constraints.