Databases involve lots of IO. When you have a lot of IO, you inherently run the risk of corruption. Your primary defense against database corruption is to take regular backups of your database and to periodically test that these backups can be restored. You need to look out for database corruption, however, and SQL Server provides tools you can use to check the consistency of your database, as well as to resolve consistency issues if backups are not available. This chapter will look at the options you have for both checking and fixing consistency issues.