Business Continuity Manager does not allow sessions on an Unrecoverable database system. All tables automatically become unrecoverable when a database system is placed in the Unrecoverable state.
A database system or table automatically becomes unrecoverable when the following occurs:
- Adding a new database system to Business Continuity Manager.
- A database system in Active, Standby, or Restore state encounters a data inconsistency during a write request.
- Tables added to Business Continuity Manager through a dictionary deploy also come up as Unrecoverable. The only exception is when the table exists only on one system and that system is in the Active state. In this case, the table is auto activated once the dictionary deployment completes.
Business Continuity Manager automatically changes the state of tables based on a recovery mechanism if tables are in different states.
For example, you have Business Continuity Manager with an active system and a standby system. A transaction runs successfully on the active system where tables X and Y are in an Active state. On running the transaction on the standby system where table Y is in an Unrecoverable state, Business Continuity Manager changes the state of the table X to Unrecoverable.
To change a table or Teradata system to Active from Unrecoverable, use SYSTEM ACTIVATE command.