Database tempdb

Even if database tempdb seems to be a regular database like many others, it plays a very special role in every SQL Server instance. This database is used by SQL Server itself as well as by developers to save temporary data such as table variables or static cursors. As this database is intended for a short lifespan (temporary data only, which can be stored during execution of stored procedure or until session is disconnected), SQL Server clears this database by truncating all data from it or by dropping and recreating this database every time when it's started.

As the tempdb database will never contain durable data, it has some special internal behavior and it's the reason why accessing data in this database is several times faster than accessing durable data in other databases. If this database is corrupted, restart SQL Server.