Description
Latches are used to guarantee consistency of non-buffer pool memory structures. This wait accumulates while SQL Server is waiting to process latch operations in Null mode. This mode is used internally and is not documented by Microsoft. Note that high values in this wait do not always mean a problem (e.g. in the case of parallelism)
Resolved by
DBAs and Developers
Suggested solutions
- If this wait is experienced further details will need to be retrieved from sys.dm_os_latch_stats
- If parallelism is a common latch wait consider optimizing heavy parallel queries via indexing
Additional research
Most common latch classes and what they mean
Diagnosing and Resolving Latch Contention on SQL Server