Re: [HACKERS] Priorities for 6.6
От | wieck@debis.com (Jan Wieck) |
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Тема | Re: [HACKERS] Priorities for 6.6 |
Дата | |
Msg-id | m10qhwl-0003kGC@orion.SAPserv.Hamburg.dsh.de обсуждение исходный текст |
Ответ на | Re: [HACKERS] Priorities for 6.6 (Hannu Krosing <hannu@trust.ee>) |
Список | pgsql-hackers |
> > Tom Lane wrote: > > > > Don Baccus <dhogaza@pacifier.com> writes: > > > While I don't doubt your analysis is correct for the case you've > > > uncovered, it doesn't explain why surrounding a bunch of selects > > > with a begin/end block greatly descreases disk activity for tables > > > that don't change. > > > > Hmm, I'm not sure why that should be, either. Anyone? > > >From a recent discussion I remember that every block that is read > in is marked as dirty, regardless of weather it is modified or not. > > It is not a genuine bug (as it only slows thong down instead of > getting wrong results), but still a misfeature. > > It is most likely an ancient quickfix for some execution path that > failed to set the dirty mark when it should have. Can't believe that this is true - uhhhhhh! If it is, then it's surely a severe BUG! Jan -- #======================================================================# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #========================================= wieck@debis.com (Jan Wieck) #
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