Re: HOT synced with HEAD - Mailing list pgsql-patches

From Pavan Deolasee
Subject Re: HOT synced with HEAD
Date
Msg-id 2e78013d0709170032u64b0c898sf2b7ad386fb661d8@mail.gmail.com
Whole thread Raw
In response to Re: HOT synced with HEAD  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: HOT synced with HEAD  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-patches


On 9/17/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Yeah.  As the code stands, anything that's XMIN_INVALID will be
considered not-HotUpdated (look at the macro...).  So far I've seen no
place where there is any value in following a HOT chain past such a
tuple --- do you see any? 

No, I don't think we would ever need to follow a HOT chain past
the aborted tuple. The only thing that worries about this setup though
is the dependency on hint bits being set properly. But the places
where this would be used right now for detecting aborted dead tuples,
apply HeapTupleSatisfiesVacuum on the tuple before checking
for HeapTupleIsHotUpdated, so we are fine. Or should we just check
for XMIN_INVALID explicitly at those places ?


Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB     http://www.enterprisedb.com

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