Horton
Menu

Re: pg_plan_advice

David G. Johnston <david.g.johnston@gmail.com>

View thread
From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Alexandra Wang <alexandra.wang.oss@gmail.com>, Richard Guo <guofenglinux@gmail.com>, Lukas Fittl <lukas@fittl.com>, Tom Lane <tgl@sss.pgh.pa.us>, Jacob Champion <jacob.champion@enterprisedb.com>, Dian Fay <di@nmfay.com>, Matheus Alcantara <matheusssilv97@gmail.com>, Jakub Wartak <jakub.wartak@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-03-02T04:10:52Z
Lists: pgsql-hackers

Attachments

On Fri, Feb 27, 2026 at 6:16 PM David G. Johnston <
david.g.johnston@gmail.com> wrote:

> On Fri, Feb 27, 2026 at 3:46 PM Robert Haas <robertmhaas@gmail.com> wrote:
>
>> On Thu, Feb 26, 2026 at 8:55 AM Robert Haas <robertmhaas@gmail.com>
>> wrote:
>> > Thanks, Alex, for the review.
>>
>> Here's v18. In addition to fixing the problems pointed out by Alex,
>> there are a couple of significant changes in this version.
>>
>>
> I have a mind to walk through the readmes and sgmls but its going to be in
> chunks.  Here's one for the readme for pg_plan_advice with a couple of
> preliminary sgml changes.
>
>
0003 sgml focus with some readme.

There is an inconsistency between readme and sgml regarding the "join
(strategy|method) advice" label.

The wording for partitionwise is better in the readme than the sgml.

I did make some bulkier suggestions - they do not contain proper markup.

There may be some repeated suggestions from my previous review - I didn't
try to match up what you did and did not take in.

I re-ordered semijoin to be alphabetical - which also had the benefit of
matching the layout of the paragraph.  Flipping the order of "former" and
"latter" is quite intentional.

I defined what "successfully enforced" means in the emit warning GUC.  That
was my unresearched guess after reading how "failed" behaves.

I found "negative join order constraint" challenging to parse.  I tried to
word it more like what is done in the readme.

I don't know if this conflicts with my previous diff of the same patch.  A
couple of overlap spots possibly but they were largely independent (readme
then, sgml now).

David J.

Commits

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

  1. pg_plan_advice: Fix another unique-semijoin bug.

  2. pg_plan_advice: Export feedback-related definitions.

  3. pg_plan_advice: Fix a bug when a subquery is pruned away entirely.

  4. pg_plan_advice: Add alternatives test to Makefile.

  5. pg_plan_advice: Handle non-repeatable TABLESAMPLE scans.

  6. pg_stash_advice: Allow stashed advice to be persisted to disk.

  7. Add pg_stash_advice contrib module.

  8. pg_plan_advice: Avoid assertion failure with partitionwise aggregate.

  9. pg_plan_advice: Invent DO_NOT_SCAN(relation_identifier).

  10. Add an alternative_plan_name field to PlannerInfo.

  11. pg_plan_advice: Refactor to invent pgpa_planner_info

  12. Respect disabled_nodes in fix_alternative_subplan.

  13. get_memoize_path: Don't exit quickly when PGS_NESTLOOP_PLAIN is unset.

  14. test_plan_advice: Set TAP test priority 50 in meson.build.

  15. pg_plan_advice: Avoid a crash under GEQO.

  16. Test pg_plan_advice using a new test_plan_advice module.

  17. pg_plan_advice: Always install pg_plan_advice.h, and in the right place

  18. pg_plan_advice: Fix failures to accept identifier keywords.

  19. Add pg_plan_advice contrib module.

  20. Allow extensions to mark an individual index as disabled.

  21. Replace get_relation_info_hook with build_simple_rel_hook.

  22. Store information about Append node consolidation in the final plan.

  23. Store information about elided nodes in the final plan.

  24. Store information about range-table flattening in the final plan.

  25. Pass cursorOptions to planner_setup_hook.

  26. Fix PGS_CONSIDER_NONPARTIAL interaction with Materialize nodes.

  27. Fix mistakes in commit 4020b370f214315b8c10430301898ac21658143f

  28. Allow for plugin control over path generation strategies.

  29. Update some comments for fasthash

  30. Allow passing a pointer to GetNamedDSMSegment()'s init callback.

  31. Don't reset the pathlist of partitioned joinrels.

  32. Treat number of disabled nodes in a path as a separate cost metric.