Re: Bitmap reuse - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Bitmap reuse
Date
Msg-id 652080.1626831138@sss.pgh.pa.us
Whole thread Raw
In response to Re: Bitmap reuse  (David Rowley <dgrowleyml@gmail.com>)
Responses Re: Bitmap reuse  (David Rowley <dgrowleyml@gmail.com>)
List pgsql-hackers
David Rowley <dgrowleyml@gmail.com> writes:
> On Wed, 21 Jul 2021 at 11:25, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Uh .... it's not the "exact same bitmap each time", because the selected
>> rows vary depending on the value of g.i.

> I imagined Jeff was meaning the bitmap from the scan of foo_x_idx, not
> the combined ANDed bitmap from both indexes.

To re-use that, you'd need a way to prevent the upper node from
destructively modifying the tidbitmap.

            regards, tom lane



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