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From Bryan Pendleton <bpendle...@amberpoint.com>
Subject Re: Releasing latches when waiting for locks. When and why?
Date Sat, 18 Nov 2006 00:12:15 GMT
> When this method is used, the specified latch will be
> released if the lock cannot be obtained immediately, and that page
> will be re-latched when the lock has been obtained.

I'm just guessing here ...

I think that there are some fairly advanced Btree traversal algorithms,
in particular situations in which you are reading backward through a
Btree which may be undergoing concurrent structural modifications by
others, in which a primitive operation like the one you describe is crucial.

So perhaps this method was included in the Store in preparation for some
access method techniques which haven't yet been implemented?



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