In my chalk/talk at TechEd yesterday, I asked the crowd “what’s the purpose of repair?” One person got it right. The purpose is not to save data. Surprised? The purpose is to get the database back to a structurally and transactionally consistent state so that processing can safely continue.

We chose the name of this repair option very carefully and it’s pretty obvious what you’re implying when you use it – “please fix up my database and if you have to delete some data to do that then – ok”.

When CHECKDB reports that the recommended repair option is REPAIR_ALLOW_DATA_LOSS, that’s because it’s going to have to delete something to repair the damaged database. We’re not talking about damaged non-clustered indexes here, we’re talking about heap or clustered index data records or pages being deleted.