Horton

Re: Optimizing nbtree ScalarArrayOp execution, allowing multi-column ordered scans, skip scan

Matthias van de Meent <boekewurm+postgres@gmail.com>

View thread
From: Matthias van de Meent <boekewurm+postgres@gmail.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Jeff Davis <pgsql@j-davis.com>, benoit <benoit@hopsandfork.com>, Alexander Korotkov <aekorotkov@gmail.com>
Date: 2023-11-07T12:20:39Z
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. Move nbtree preprocessing into new .c file.

  2. Fix nbtree lookahead overflow bug.

  3. Remove unneeded nbtree array preprocessing assert.

  4. Don't try to fix eliminated nbtree array scan keys.

  5. Remove redundant nbtree preprocessing assertions.

  6. Avoid extra lookups with nbtree array inequalities.

  7. Enhance nbtree ScalarArrayOp execution.

  8. Improvements and fixes for e0b1ee17dc

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

  10. Fix btmarkpos/btrestrpos array key wraparound bug.

  11. Add nbtree high key "continuescan" optimization.

  12. Consider secondary factors during nbtree splits.

  13. Make heap TID a tiebreaker nbtree index column.

  14. Fix planning of btree index scans using ScalarArrayOpExpr quals.

  15. Fix btree stop-at-nulls logic properly.

  16. Teach btree to handle ScalarArrayOpExpr quals natively.

On Tue, 7 Nov 2023 at 00:03, Peter Geoghegan <pg@bowt.ie> wrote:
>
> On Mon, Nov 6, 2023 at 1:28 PM Matthias van de Meent
> <boekewurm+postgres@gmail.com> wrote:
> > I'm planning on reviewing this patch tomorrow, but in an initial scan
> > through the patch I noticed there's little information about how the
> > array keys state machine works in this new design. Do you have a more
> > toplevel description of the full state machine used in the new design?
>
> This is an excellent question. You're entirely right: there isn't
> enough information about the design of the state machine.
>
> I should be able to post v6 later this week. My current plan is to
> commit the other nbtree patch first (the backwards scan "boundary
> cases" one from the ongoing CF) -- since I saw your review earlier
> today. I think that you should probably wait for this v6 before
> starting your review.

Okay, thanks for the update, then I'll wait for v6 to be posted.

Kind regards,

Matthias van de Meent
Neon (https://neon.tech)