tempdb
So what is tempdb? Well… it’s is a system database that is used by queries that contain: joins, aggregations, cursors, xml variables, triggers, online index builds, sorting, hash matching, temp tables or table variables. There are other bits that use tempdb, but they’re beyond me right now…
How should it be configured?
8 tempdb files, 1024mb initial size, 256mb auto growth (unlimited), all located in the same directory.
The files must be evenly sized, otherwise more traffic will go to the largest file.