Waitopedia is a comprehensive resource of information about SQL Server waits.

The description shown below is the top answer as voted by the Spotlight community.

The charts are based on 2.1 TB of data collected from 4207 instances uploaded by 323 Spotlight users over an 8 week period.


Category: Memory
SQL Server versions: 2005, 2008, 2008 R2, 2012, 2014, 2016, 2017


1 Answer


Occurs when the number of concurrent query compilations reaches a throttling limit. High waits and wait times may indicate excessive compilations, recompiles, or uncachable plans. Information from Microsoft®

Very rare

This wait never occurs for most instances

For each of 4207 instances, we ranked RESOURCE_SEMAPHORE_QUERY_COMPILE on how frequent it is compared to all other recent waits. The chart shows the total of all rankings.

Prevalence of RESOURCE_SEMAPHORE_QUERY_COMPILE across the Spotlight Population

For 65 % of hours with this wait, average wait time is less than 130 ms

For each instance, we found all the recent hours when it had a RESOURCE_SEMAPHORE_QUERY_COMPILE wait. We found the average latency for each of those hours.

285 instances contributed data to this chart

Latency Distribution of RESOURCE_SEMAPHORE_QUERY_COMPILE across the Spotlight Population