Modifications to temporal tables can be current, sequenced, or nonsequenced. These operations apply to the valid-time dimension. The system automatically determines which rows are to be modified based on the interaction between the period of validity of each row and the period of applicability of the modification SQL.
With respect to the transaction-time dimension of transaction-time and bitemporal tables, a row is considered either open or closed. Open rows participate in database operations. Closed rows are historical snapshots of rows that have been deleted or modified subsequent to a prior state. After a row has been closed, it no longer participates in normal SQL operations, but can be viewed using temporal SQL.
Rows that have been closed in the transaction-time dimension remain as a permanent log of database operations on these rows. They are not available to be deleted or modified. However, these rows can be deleted and modified by users having the special NONTEMPORAL privilege, provided that capability is enabled in the database.