I walked into a client engagement where I really got stuck with a very interesting scenario with a client with PREEMPTIVE_OS_RSFXDEVICEOPS Wait Type.
SQL SERVER – Brief Note About RESOURCE_SEMAPHORE_QUERY_COMPILE Wait Type Resource
Today we will see Brief Note About RESOURCE_SEMAPHORE_QUERY_COMPILE Wait Type resource. I wrote a blog post about Enable Lock Pages in Memory LPIM.
Query Runs Slow Occasionally: Five Checks to Find Why
When a query runs slow occasionally, the cause sits around the query: a lock, a job, a file growth, tempdb or a shortage of worker threads. This post gives one tested T-SQL check for each and a small demo for blocking and file growth. It also says what to do when all five checks find nothing.
Signal Waits: Detect CPU Pressure With Wait Statistics
Signal waits are the part of every wait that a task spends in the queue for a free CPU. This post ranks the wait types by signal time, shows why timer waits ruin the total share, and samples the signal share into a small table so a whole working day can be read interval by interval.
THREADPOOL Waits: When Raising Max Worker Count Helps
THREADPOOL waits mean tasks waited for a worker thread. Five read-only queries separate real thread starvation from blocking and busy CPUs. The post lists five signs and shows how to raise the cap in small steps.
SQL SERVER – Query Specific Wait Statistics and Performance Tuning
Query Specific Wait Statistics helped explain a sudden customer-query slowdown. The remaining workload ran normally, and recompilation had not helped.
SQL SERVER – What is Wait Type Parallel Backup Queue?
Only official documentation which I could find was about wait statistics related to Parallel Backup Queue is very little available online.