Validating date in oracle
Bitmap indexes are widely used in data warehousing environments.
The environments typically have large amounts of data and ad hoc queries, but a low level of concurrent DML transactions.
Moreover, unfortunately the change tracking file cannot be moved without shutting down the database, moving it with the appropriate ALTER DATABASE RENAME FILE command, and then restarting the database.
Oracle does recommend that this feature be activated for any database whose disaster recovery plan utilizes incremental backups of differing levels.
Oracle also notes that theirs is a small performance hit during normal operations, but that hit should be discounted against the need to avoid scans of datafiles during restoration and recovery operations.
This error message will identify the file that the corrupt block is in.Read the Block Change Tracking File to determine which blocks in the data file need to be read. Scan only the changed blocks in the data file and then back them up.The size of the block change tracking file is proportional to: - The database size in bytes: the block change tracking file contains data representing every data file block in the database.Therefore, performing an incremental backup on a very large database could take some time, even if only a few blocks were changed.You can create a block change tracking file that records the blocks modified since the last backup.