Re: Optimizer improvements: to do or not to do?
От | Joshua Reich |
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Тема | Re: Optimizer improvements: to do or not to do? |
Дата | |
Msg-id | 450880ED.6040509@root.net обсуждение исходный текст |
Ответ на | Re: Optimizer improvements: to do or not to do? (Ron Mayer <rm_pg@cheapcomplexdevices.com>) |
Ответы |
Re: Optimizer improvements: to do or not to do?
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Список | pgsql-hackers |
Ron Mayer wrote: > Gregory Stark wrote: > >> Ron Mayer <rm_pg@cheapcomplexdevices.com> writes: >> >>> ...vastly overestimate the number of pages .. because postgresql's guess >>> at the correlation being practically 0 despite the fact that the distinct >>> values for any given column are closely packed on a few pages. >>> >> I think we need a serious statistics jock to pipe up with some standard >> metrics that do what we need. Otherwise we'll never have a solid footing for >> the predictions we make and will never know how much we can trust them. >> > > Do we know if any such people participate/lurk on this list, or > if the conversation should go elsewhere? > I lurk... I don't know if I'm a 'statistics jock', but I may be valuable if only I had a better understanding of how the optimizer works. I have been following this thread with interest, but could really do with a good pointer to background information beyond what I have read in the main postgres manual. Does such information exist, and if so, where ? Josh Reich
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