Re: Bitmap reuse - Mailing list pgsql-hackers

From David Rowley
Subject Re: Bitmap reuse
Date
Msg-id CAApHDvptE7BERTdygz78NdH-s6Ztbov6-iUgyzhhWOzj33M7hA@mail.gmail.com
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In response to Re: Bitmap reuse  (David Rowley <dgrowleyml@gmail.com>)
List pgsql-hackers
On Thu, 22 Jul 2021 at 01:54, David Rowley <dgrowleyml@gmail.com> wrote:
> Maybe the planner would need to be involved in making the decision of
> if the bitmap index scan should tuck away a carbon copy of the
> resulting TIDBitmap after the first scan.  That way on rescan we could
> just make a copy of the cached version and return that.  That saves
> having to modify the callers to tell them not to damage the returned
> TIDBitmap.

Oh but, meh. Caching could blow out work_mem...  We might end up using
work_mem * 2.

David



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