You can use ROLLBACK or ROLLFORWARD utility commands to recover base tables with join indexes defined on them; however, the indexes are not rebuilt during the recovery process.
Instead, any such join index is marked as nonvalid, and you must drop and recreate it before the Optimizer can use it again in a query plan.
When a join index has been marked not valid, the SHOW JOIN INDEX statement displays a special status message to inform you that the index has been so marked.