Wednesday, September 29, 2010

Partition offset and allocation unit size of a disk for SQL Server

SQL Server performance is dependent on the server resources available and disk performance is probably the most important resource.  To maximize disk performance for SQL Server, I've always been told that the drive's partition offset must be set to 32K and the allocation unit size set to 64K for partitions that hold data and 8K for partitions that hold logs.  How do I find out the allocation unit size and partition offset for my drives?.

Thursday, September 2, 2010

How Old Are Your Database Statistics?

Unlike fine wine, database statistics do not improve with age. I recently helped out with a client who was having issues with poor query performance on a SQL Server 2005 instance on very good hardware. After having them run my standard SQL Server 2005 Diagnostic Information queries, nothing glaringly obvious was jumping out at me. Sure, there were a couple of missing indexes that needed to be added, but overall query performance was still pretty bad. The server as a whole was not under obvious CPU, memory, or IO pressure.