Search Postgresql Archives

Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Subject: Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
From: David Rowley <dgrowleyml@xxxxxxxxx>
Date: Sat, 11 May 2024 13:37:10 +1200
Cc: Dimitrios Apostolou <jimis@xxxxxxx>, pgsql-general@xxxxxxxxxxxxxxxxxxxx
In-reply-to: <1685688.1715391218@sss.pgh.pa.us>
References: <7886a68f-b466-2131-1747-f69f0fb71a37@gmx.net> <69077f15-4125-2d63-733f-21ce6eac4f01@gmx.net> <559b0e40-63e6-fa9a-6b03-d1eba10f30f8@gmx.net> <1629463.1715372568@sss.pgh.pa.us> <6a2f3906-3d7a-6924-7403-8f77d57a18e4@gmx.net> <1685688.1715391218@sss.pgh.pa.us>

On Sat, 11 May 2024 at 13:33, Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
> I do kind of wonder why it's producing both a hashagg and a Unique
> step --- seems like it should do one or the other.

It still needs to make the duplicate groups from parallel workers unique.

David

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Follow-Ups:
- Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Dimitrios Apostolou

References:
- SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Dimitrios Apostolou
- Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Dimitrios Apostolou
- Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Dimitrios Apostolou
- Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Tom Lane
- Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Dimitrios Apostolou
- Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
  - From: Tom Lane

Prev by Date: Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
Next by Date: Unnecessary buffer usage with multicolumn index, row comparison, and equility constraint
Previous by thread: Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
Next by thread: Re: SELECT DISTINCT chooses parallel seqscan instead of indexscan on huge table with 1000 partitions
Index(es):
- Date
- Thread

[Index of Archives] [Postgresql Jobs] [Postgresql Admin] [Postgresql Performance] [Linux Clusters] [PHP Home] [PHP on Windows] [Kernel Newbies] [PHP Classes] [PHP Databases] [Postgresql & PHP] [Yosemite]