Re: Adding skip scan (including MDAM style range skip scan) to nbtree - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Adding skip scan (including MDAM style range skip scan) to nbtree
Date
Msg-id CAH2-WzmdOETpceTr3wsTTTpu8jvNkYitw86uaGmiRZxJpL=p0A@mail.gmail.com
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In response to Re: Adding skip scan (including MDAM style range skip scan) to nbtree  (Peter Geoghegan <pg@bowt.ie>)
Responses Re: Adding skip scan (including MDAM style range skip scan) to nbtree
List pgsql-hackers
On Fri, May 9, 2025 at 9:59 AM Peter Geoghegan <pg@bowt.ie> wrote:
> I don't actually think that this kind of scan would have been affected
> by those known regressions -- since they don't use array keys. But it
> is definitely true that the queries that you're looking at very much
> rely on the optimization from commit 8a510275 (or its predecessor
> optimization, the "pstate.prechecked" optimization). As I said, my
> performance validation didn't target individual commits.

Wait, that's not it, either. Since the index scan that you use won't
find any matching tuples at all. It should land on the leftmost leaf
page, find that there are no tuples "WHERE bid = 0", ending the scan
before it ever really began.

--
Peter Geoghegan



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