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: Lock
SQL Server versions: 2000, 2005, 2008, 2008 R2, 2012, 2014, 2016, 2017

What is LCK_M_S?

1 Answer


Occurs when a task is waiting to acquire a Shared lock. Information from Microsoft®

Somewhat common

This wait is somewhat common for most instances

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

Prevalence of LCK_M_S across the Spotlight Population

For 83 % of hours with this wait, average wait time is less than 55 ms

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

2745 instances contributed data to this chart

Latency Distribution of LCK_M_S across the Spotlight Population