Parallel Query - Mailing list pgsql-performance

From Luís Roberto Weck
Subject Parallel Query
Date
Msg-id 732b7303-8b60-2f33-7f00-3b0cd70a7c5b@siscobra.com.br
Whole thread Raw
Responses Re: Parallel Query
Re: Parallel Query
List pgsql-performance
Hi!

Is there a reason query 3 can't use parallel workers? Using q1 and q2 
they seem very similar but can use up to 4 workers to run faster:

q1: https://pastebin.com/ufkbSmfB
q2: https://pastebin.com/Yt32zRNX
q3: https://pastebin.com/dqh7yKPb

The sort node on q3 takes almost 12 seconds, making the query run on 68  
if I had set enough work_mem to make it all in memory.

Running version 10.10.



pgsql-performance by date:

Previous
From: Marco Colli
Date:
Subject: Re: Slow "not in array" operation
Next
From: Jeff Janes
Date:
Subject: Re: Parallel Query