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

On Tue, Jul 2, 2024 at 9:30 AM Peter Geoghegan <pg@bowt.ie> wrote:
> > EXPLAIN [ANALYZE] SELECT COUNT(*) FROM test1 WHERE n > 900_000_000;
>
> For example, this first test query goes from needing a full index scan
> that has 5056 buffer hits to a skip scan that requires only 12 buffer
> hits.

Actually, looks like that's an invalid result. The "char" opclass
support function appears to have bugs.

My testing totally focussed on types like integer, date, and UUID. The
"char" opclass was somewhat of an afterthought. Will fix "char" skip
support for v2.

--
Peter Geoghegan