Dropping any type of column from a transaction-time or bitemporal table requires the NONTEMPORAL privilege on the table, and the NONTEMPORAL qualifier to ALTER TABLE must be used.
Consider the following transaction-time table:
CREATE MULTISET TABLE Customer ( Customer_Name VARCHAR(40), Customer_ID INTEGER, Customer_Address VARCHAR(80), Customer_Phone VARCHAR(12), Customer_Duration PERIOD(TIMESTAMP(6) WITH TIME ZONE) NOT NULL AS TRANSACTIONTIME ) PRIMARY INDEX ( Customer_ID );
Assuming that you have the NONTEMPORAL privilege on the Customer table, the following ALTER TABLE statement drops the Customer_Duration column:
NONTEMPORAL ALTER TABLE Customer DROP Customer_Duration;
When a transaction-time column is dropped from a transaction-time or bitemporal table, all closed rows (all history rows in the transaction-time dimension) are physically deleted from the table.