Can anyone explain to me what the difference between 'An average SQL queue size' and 'An average disk queue size' is? I've asked all of our DBAs and only one of them knew that there was a difference. We can find the Avg Disk Queue Length in Perfmon, but don't know which counter outlines the 'SQL queue size'. Any suggestions welcome! Thanks.
I've never heard of a SQL queue. Queuing is simply the measure of processes waiting on resources. There isn't a 'SQL' resource. You'll see queuing for CPU, disk and memory. Measuring the size of those through the performance counters gives you an indication of load and possibly bottlenecks on the system.