Re: PATCH: postpone building buckets to the end of Hash (in HashJoin) - Mailing list pgsql-hackers

From Tomas Vondra
Subject Re: PATCH: postpone building buckets to the end of Hash (in HashJoin)
Date
Msg-id 56732909.1070304@2ndquadrant.com
Whole thread Raw
In response to Re: PATCH: postpone building buckets to the end of Hash (in HashJoin)  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: PATCH: postpone building buckets to the end of Hash (in HashJoin)  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
List pgsql-hackers
Hi,

On 12/17/2015 07:20 PM, Robert Haas wrote:
...
>
> If this doesn't regress performance in the case where the number of
> buckets is estimated accurately to begin with, then I think this is
> a great idea. Can you supply some performance tests results for that
> case, and maybe some of the other cases also?

I don't see how it could regress performance, and the benchmarks I've 
done confirm that. I'll do more thorough benchmarking and post the 
results here, but not now as this patch is in 2016-01 CF and I want to 
put all my time into reviewing patches from the open commitfest.

regards

--
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



pgsql-hackers by date:

Previous
From: Mart Kelder
Date:
Subject: Re: [PoC] Asynchronous execution again (which is not parallel)
Next
From: Robert Haas
Date:
Subject: Re: Remove array_nulls?