Re: [PoC] Reducing planning time when tables have many partitions

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: Amit Langote <amitlangote09@gmail.com>

Cc: David Rowley <dgrowleyml@gmail.com>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Yuya Watari <watari.yuya@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Dmitry Dolgov <9erthalion6@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>, jian he <jian.universality@gmail.com>, Alena Rybakina <lena.ribackina@yandex.ru>, Andrei Lepikhov <a.lepikhov@postgrespro.ru>, Thom Brown <thom@linux.com>, Zhang Mingli <zmlpostgres@gmail.com>

Date: 2025-04-09T05:19:45Z

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 →

Update wording in optimizer/README for EquivalenceClasses
- d7c04db27aeb 18.0 landed
Speedup child EquivalenceMember lookup in planner
- d69d45a5a956 18.0 landed
Allow planner to use Merge Append to efficiently implement UNION
- 66c0185a3d14 17.0 cited
Remove trailing zero words from Bitmapsets
- a8c09daa8bb1 17.0 cited
Make Vars be outer-join-aware.
- 2489d76c4906 16.0 cited
Avoid making commutatively-duplicate clauses in EquivalenceClasses.
- a5fc46414deb 16.0 cited

Amit Langote <amitlangote09@gmail.com> writes:
> Should the following paragraph in src/backend/optimizer/README be
> updated to reflect the new reality after recent changes?

>     An EquivalenceClass can contain "em_is_child" members, which are copies
>     of members that contain appendrel parent relation Vars, transposed to
>     contain the equivalent child-relation variables or expressions.

Hm.  They still are "in" the EquivalenceClass in a very real sense;
there is no other data structure that links to them.  So this isn't
incorrect.  I do get your feeling that maybe some rewording is
warranted, but I'm not sure what.

			regards, tom lane