Re: Why does query planner choose slower BitmapAnd ?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Seamus Abshere <seamus(at)abshere(dot)net>
Cc: Stephen Frost <sfrost(at)snowman(dot)net>, pgsql-general(at)postgresql(dot)org
Subject: Re: Why does query planner choose slower BitmapAnd ?
Date: 2016-02-22 17:25:28
Message-ID: 25689.1456161928@sss.pgh.pa.us
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Seamus Abshere <seamus(at)abshere(dot)net> writes:
> On Mon, Feb 22, 2016, at 02:14 PM, Tom Lane wrote:
>> IOW, almost certainly we *don't* realize that the query will involve scanning through gigabytes of index pages. But btree indexes are much simpler and easier to make that estimate for...

> Isn't this the crux of my issue, at least?

Not unless you are using a GIST index for booleans, which I sure hope you
ain't.

regards, tom lane

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