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

On Thu, Feb 27, 2025 at 1:23 PM Peter Geoghegan <pg@bowt.ie> wrote:
> Attached is v26, which has no functional changes. This is just to fix
> yet more bitrot.

Attached is v27, which fixes bitrot. It also has some notable changes:

* New approach to "Index Searches: N" instrumentation patch, following
the recent revert of the original approach following
"debug_parallel_query=regress" buildfarm failures.

This is being discussed over on the thread that I started to discuss
the EXPLAIN ANALYZE instrumentation work:

https://www.postgresql.org/message-id/CAH2-Wzk%2BcXBD1tnhQ-oagHuY9Fw5uArJE%2BLxfAP2VjZmDawbeQ%40mail.gmail.com

* New patch that makes BTMaxItemSize not require a "Page" arg, so that
it can be used in contexts where a page image isn't close at hand.
This is preparation for the approach taken to parallel index scans,
where we apply a conservative "1/3 of a page" worst case limit on the
size of a datum, but don't have a page to pass to BTMaxItemSize.

I plan on committing this one soon. It's obviously pretty pointless to
make the BTMaxItemSize operate off of a page header, and not requiring
it is more flexible.

--
Peter Geoghegan