LATCH_KP
Occurs when waiting for a KP (keep) latch. This does not include buffer latches or transaction mark latches.
Detailed Description​
Latches are lightweight, fast methods of managing concurrency on a specific resource. This group of latches are seen in management of pages that have already been read into memory.
Books online says "Occurs when waiting for a KP (keep) latch. This does not include buffer latches or transaction mark latches. A listing of LATCH_* waits is available in sys.dm_os_latch_stats. Note that sys.dm_os_latch_stats groups LATCH_NL, LATCH_SH, LATCH_UP, LATCH_EX, and LATCH_DT waits together".
How to reduce this wait​
There is a great article in sqlskills.com under the LATCH_EX page which gives a breakdown of the steps needed to identify the latch which you are waiting on - as although the wait time is shown, it does not identify the specific latch being contended for.
Additional Links​
- Microsoft Docs - sys.dm_os_wait_stats (Transact-SQL)
- sqlskills.com - LATCH_SH
- sqlshack.com - All about latches
Search online​
If this article doesn't have the information you need you can try searching online. Remember, you can contribute suggestions to this page.