Why are queries slower in sql 2012 with Vmware than 2008 without Vmware
My queries are slower since we upgraded to SQL 2012 with vwmare. I have the same query but different environments. Here is the Parallelism for both servers Cost Threshold for Parallelism = 5 Max Degree of Parallelism = 0
There are huge numbers of reasons why you could have differences. Your starting from two different versions of SQL Server. That alone could cause differences in execution plans due to changes in how the optimizer works between versions. Then you need to take into account that you're going from, assuming, dedicated hardware to a shared environment within VMWare. There are a large number of settings within the VM environment that can negatively impact SQL Server. I suggest doing a search on the VMWare web site. They have a document on how to configure VMWare optimally for SQL Server. You didn't even get into the differences in memory and CPU between the VM and the hardware. Even if they are the same, they could still be different because within a VM environment those may be, usually are, share resources. And, they can be affected by those settings within VMWare that I mentioned earlier. Parallelism is not the only way to adjust query behavior. But, one thing I would suggest, on all your servers, change the default value for the Cost Threshold from 5 to something much higher. I usually recommend 40 as a starting point.