Re: Why does query planner choose slower BitmapAnd ?

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От Seamus Abshere
Тема Re: Why does query planner choose slower BitmapAnd ?
Дата
Msg-id 1456163618.1013318.528482610.2E35A103@webmail.messagingengine.com
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Ответ на Re: Why does query planner choose slower BitmapAnd ?  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: Why does query planner choose slower BitmapAnd ?  (Seamus Abshere <seamus@abshere.net>)
Список pgsql-general
On Mon, Feb 22, 2016, at 02:49 PM, Tom Lane wrote:
> Seamus Abshere <seamus@abshere.net> writes:
> > Inspired, I changed cpu_index_tuple_cost to 0.1 (default: 0.005). It "fixed" my problem by preventing the
BitmapAnd.
> > Is this dangerous?
>
> Use a gentle tap, man, don't swing the hammer with quite so much abandon.
> I'd have tried doubling the setting to start with.  Raising it 20X might
> cause other queries to change behavior undesirably.

Doubling it was enough :)


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