Re: pg_plan_advice

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Jakub Wartak <jakub.wartak@enterprisedb.com>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-11-04T19:54:44Z

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 →

Add pg_plan_advice contrib module.
- 5883ff30b02c 19 (unreleased) landed
Store information about Append node consolidation in the final plan.
- 7358abcc6076 19 (unreleased) landed
Store information about elided nodes in the final plan.
- 0d4391b265f8 19 (unreleased) landed
Store information about range-table flattening in the final plan.
- adbad833f3d9 19 (unreleased) landed
Allow for plugin control over path generation strategies.
- 4020b370f214 19 (unreleased) landed
Allow passing a pointer to GetNamedDSMSegment()'s init callback.
- 48d4a1423d2e 19 (unreleased) cited
Don't reset the pathlist of partitioned joinrels.
- 014f9a831a32 19 (unreleased) cited

Attachments

v2-0005-Allow-for-plugin-control-over-path-generation-str.patch (application/octet-stream) patch v2-0005
v2-0003-Store-information-about-Append-node-consolidation.patch (application/octet-stream) patch v2-0003
v2-0002-Store-information-about-elided-nodes-in-the-final.patch (application/octet-stream) patch v2-0002
v2-0001-Store-information-about-range-table-flattening-in.patch (application/octet-stream) patch v2-0001
v2-0004-Temporary-hack-to-unbreak-partitionwise-join-cont.patch (application/octet-stream) patch v2-0004
v2-0006-WIP-Add-pg_plan_advice-contrib-module.patch (application/octet-stream) patch v2-0006

On Fri, Oct 31, 2025 at 5:59 AM Jakub Wartak
<jakub.wartak@enterprisedb.com> wrote:
> My gcc-13 was nitpicking a little bit (see
> compilation_warnings_v1.txt), so attached is just a tiny diff to fix
> some of those issues. After that, clang-20 run was clean too.

Here's v2. Change log:

- Attempted to fix the compiler warnings. I didn't add elog() before
pg_unreachable() as you suggested; instead, I added a dummy return
afterwards. Let's see if that works. Also, I decided after reading the
comment for list_truncate() that what I'd done there was not going to
be acceptable, so I rewrote the code slightly. It now copies the list
when adding to it, instead of relying on the ability to use
list_truncate() to recreate the prior tstate.

- Deleted the SQL-callable pg_parse_advice function and related code.
That was useful to me early in development but I don't think anyone
will need it at this point; if you want to test whether an advice
string can be parsed, just try setting pg_plan_advice.advice.

- Fixed a couple of dumb bugs in pgpa_trove.c.

- Added a few more regression test scenarios.

- Fixed a couple of typos/thinkos.

-- 
Robert Haas
EDB: http://www.enterprisedb.com