New Article: VMware CPU Hot Plug vNUMA Effects on SQL Server

My latest article on SQLPerformance.com was published today and highlights the potential for performance problems while using the hot-add vCPU feature in ESX 5+ with wide VMs for SQL Server.

http://www.sqlperformance.com/2013/12/system-configuration/vmware-cpu-hot-plug-vnuma-effects-on-sql-server

This is a potentially hidden problem with serious performance implications that should be checked for if you are using VMware to run wide VMs with greater than 8 vCPUs on NUMA hardware.

New Article – How expensive are column-side Implicit Conversions?

Last week I blogged about Implicit Conversions that cause Index Scans, and showed two charts for where implicit conversions could result in an index scan operation instead of an index seek during query execution.  As a part of writing that blog post I thought it would be interesting to also look at the performance overhead of the column-side implicit conversion occurring, given that I’ve seen it’s effects a number of times in the last few weeks.  Today my article How expensive are column-side Implicit Conversions? went live on the SQLPerformance.com site to show using Performance Monitor information on CPU usage and batch requests per second, the effect of the performance overhead when column-side implicit conversions occur that cause index scans during query execution.

New Article: Performance Problems with SQL Server 2012 Enterprise Edition Under CAL Licensing

My latest article on SQLPerformance.com was published yesterday and highlights the potential for performance problems while using the default configuration of SQL Server 2012 using the Enterprise Server+CAL upgrade licensing under Software Assurance.

http://www.sqlperformance.com/2012/11/system-configuration/2012-cal-problems