Latch-Related Wait Types
In the previous chapter we took a pretty deep look at locking and blocking inside SQL Server, together with different Wait Types that indicate blocking is occurring. Latches look a lot like the locks we discussed earlier; in some cases they even appear to use the same modes as the locks we discussed in the previous chapter. Make no mistake though, latches are completely different than locks, even though they seem to share some features. While locks are used to guarantee transactions are isolated and consistent, latches are used to guarantee the consistency of in-memory objects.
Latches are, just like locking ...