Horton

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

Andrei Lepikhov <a.lepikhov@postgrespro.ru>

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From: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
To: Yuya Watari <watari.yuya@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, David Rowley <dgrowleyml@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2022-11-08T11:31:04Z
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.

On 2/11/2022 15:27, Yuya Watari wrote:
> I noticed that the previous patch does not apply to the current HEAD.
> I attached the rebased version to this email.
Looking into find_em_for_rel() changes I see that you replaced
if (bms_is_subset(em->em_relids, rel->relids)
with assertion statement.
According of get_ecmember_indexes(), the em_relids field of returned 
equivalence members can contain relids, not mentioned in the relation.
I don't understand, why it works now? For example, we can sort by t1.x, 
but have an expression t1.x=t1.y*t2.z. Or I've missed something? If it 
is not a mistake, maybe to add a comment why assertion here isn't failed?

-- 
regards,
Andrey Lepikhov
Postgres Professional