SQL Server DBCC CHECKDB repair

The default DBCC CHECKDB only do database detection database is intact, do not actively do database repair, to repair the database, the database needs to set up a single mode.

1. Repair_allow_data_loss may result in loss of data.

2, Repair_fast did not perform any repair operation.

3, Repair_rebuild quick repair.

1, Repaire_allow_data_loss repair the three processes:

The first step is to re-mark pages that are marked as inaccessible as accessible, as if these errors never happened.

The second step is to restore the database with regular log recovery techniques.

In the third step, if the log file is corrupted and the recovery fails, the log will be rebuilt, which can cause transactional consistency to be not guaranteed.

2, Repaire_allow_data_loss not successful:

The first: Restore the database based on the previously backed-up files.

The second type: If the damage occurs only on an object, you can drop the object.

3, there is nothing to do DBCC CHECKDB it is very impact performance.

SQL Server DBCC CHECKDB repair