Re: The planner hates me.
От | Scott Marlowe |
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Тема | Re: The planner hates me. |
Дата | |
Msg-id | dcc563d10809250906n3e90e3b1r602db291de8594e@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: The planner hates me. (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: The planner hates me.
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Список | pgsql-general |
On Thu, Sep 25, 2008 at 9:38 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > The problem you've got here is that the planner has got absolutely no > visibility into the behavior of get_dates(). In particular it doesn't > realize that the values being generated are close to the end of the > range of dates that are in the table, and thus the date1 >= dates.date > condition is far more selective than the date2 < dates.date condition. > If you look closely at the rowcount estimates you'll see that those are > actually being estimated the same, to within roundoff error. So looking > at two indexes instead of one doesn't look like a win to it. Couldn't they make a simple immutable function and index on that?
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