Re: Weird explain output
От | wd |
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Тема | Re: Weird explain output |
Дата | |
Msg-id | CABexzmhRDSkGB+4sN+r7fsZHVQ+Otc77ybXy8CocHOJjW6HGnw@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Weird explain output (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-general |
Thanks for your reply. On Mon, Feb 4, 2013 at 3:48 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > You're worrying about the wrong thing entirely. The right thing to be > worrying about is why are some of those row estimates off by four orders > of magnitude, and what you can do to fix that. The planner will never > deliver sane plans when its estimates are so far off from reality. > > You mean the rows from explain is bigger then the rows real returned? It caused by a sub query with a filter like ( a and b ) or ( c and d ), I've tried to create a temp table for it, the explained rows and the real rows will similarly. Here is the full output, http://explain.depesz.com/s/M7oo > From my perspective, you snipped all the interesting parts of this > output, because the misestimation is evidently happening somewhere down > in there. > > regards, tom lane >
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