Horton

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

amit <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, 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: 2025-04-09T05:08:53Z
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. Update wording in optimizer/README for EquivalenceClasses

  2. Speedup child EquivalenceMember lookup in planner

  3. Allow planner to use Merge Append to efficiently implement UNION

  4. Remove trailing zero words from Bitmapsets

  5. Make Vars be outer-join-aware.

  6. Avoid making commutatively-duplicate clauses in EquivalenceClasses.

Hi David,

On Wed, Apr 9, 2025 at 5:12 AM David Rowley <dgrowleyml@gmail.com> wrote:
> On Wed, 9 Apr 2025 at 02:24, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >
> > David Rowley <dgrowleyml@gmail.com> writes:
> > > I've pushed the patch now. Thanks for all the reviews of my adjustments.
> >
> > Shouldn't the CF entry be marked committed?
>
> I've done that now.

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. These
    members are not full-fledged members of the EquivalenceClass and do not
    affect the class's overall properties at all. They are kept only to
    simplify matching of child-relation expressions to EquivalenceClasses.
    Most operations on EquivalenceClasses should ignore child members.

The part about these being in the EquivalenceClass might be worth
rewording now that we keep them in a separate array.

-- 
Thanks, Amit Langote