Horton

Re: Adding skip scan (including MDAM style range skip scan) to nbtree

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Masahiro Ikeda <ikedamsh@oss.nttdata.com>, Tomas Vondra <tomas@vondra.me>, Masahiro.Ikeda@nttdata.com, pgsql-hackers@lists.postgresql.org, Masao.Fujii@nttdata.com
Date: 2025-03-08T16:43:33Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. nbtree: Always set skipScan flag on rescan.

  2. meson: Build numeric.c with -ftree-vectorize.

  3. Fix "variable not found in subplan target lists" in semijoin de-duplication.

  4. Revert "nbtree: Remove useless row compare arg."

  5. nbtree: Remove useless row compare arg.

  6. Prevent premature nbtree array advancement.

  7. nbtree: tighten up array recheck rules.

  8. Avoid treating nonrequired nbtree keys as required.

  9. Adjust overstrong nbtree skip array assertion.

  10. Make NULL tuple values always advance skip arrays.

  11. Avoid extra index searches through preprocessing.

  12. Improve nbtree skip scan primitive scan scheduling.

  13. Further optimize nbtree search scan key comparisons.

  14. Add nbtree skip scan optimization.

  15. Improve nbtree array primitive scan scheduling.

  16. nbtree: Make BTMaxItemSize into object-like macro.

  17. Show index search count in EXPLAIN ANALYZE, take 2.

  18. Make parallel nbtree index scans use an LWLock.

  19. Show index search count in EXPLAIN ANALYZE.

  20. Avoid nbtree parallel scan currPos confusion.

  21. nbtree: Remove useless 'strat' local variable.

  22. Normalize nbtree truncated high key array behavior.

  23. Refactor handling of nbtree array redundancies.

  24. Fix nbtree pgstats accounting with parallel scans.

  25. Avoid parallel nbtree index scan hangs with SAOPs.

  26. Show Parallel Bitmap Heap Scan worker stats in EXPLAIN ANALYZE

  27. Enhance nbtree ScalarArrayOp execution.

  28. Skip checking of scan keys required for directional scan in B-tree

  29. Instead of using a numberOfRequiredKeys count to distinguish required

Attachments

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