Horton

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

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Yuya Watari <watari.yuya@gmail.com>
Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, 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>, David Rowley <dgrowleyml@gmail.com>, Thom Brown <thom@linux.com>, Zhang Mingli <zmlpostgres@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2024-12-13T10:53:17Z
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.

Hello,

On 2024-Dec-13, Yuya Watari wrote:

> Thank you for your reply, and I'm sorry if my previous emails caused
> confusion or made it seem like I was ignoring more important issues.

Not to worry!

> > Memory usage and planning time in production builds [are] important.
> > You can better spend your energy there.
> 
> As you said, we have another big problem, which is memory usage. I
> will focus on the memory usage problem first, as you suggested.

That's great, thanks.

BTW I forgot to mention it yesterday, but I was surprised that you
attached Ashutosh's old patch for planner memory usage reporting.
This feature is already in EXPLAIN (MEMORY), so you don't need any patch
to measure memory consumption ... or does your patch add some detail
that isn't already in the code?

> After fixing those problems, we can revisit the assert-enabled build
> regressions as a final step if necessary. What do you think about this
> approach?

Sounds good.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"I can't go to a restaurant and order food because I keep looking at the
fonts on the menu.  Five minutes later I realize that it's also talking
about food" (Donald Knuth)