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_RX_U?

1 Answer


Occurs when a task is waiting to acquire an Update lock on the current key value, and an Exclusive range lock between the current and previous key. Information from Microsoft®


This wait has never occurred recently

LCK_M_RX_U has not occurred recently on 4207 instances checked.

Prevalence of LCK_M_RX_U across the Spotlight Population