Re: Erroneous cost estimation for nested loop join - Mailing list pgsql-hackers

From KAWAMICHI Ryoji
Subject Re: Erroneous cost estimation for nested loop join
Date
Msg-id 1696266773.13042205.1447316511952.JavaMail.zimbra@tkl.iis.u-tokyo.ac.jp
Whole thread Raw
In response to Re: Erroneous cost estimation for nested loop join  (Gavin Flower <GavinFlower@archidevsys.co.nz>)
List pgsql-hackers

<GavinFlower@archidevsys.co.nz> wrote:
> 
> More knowledgeable people are sure to reply in more detail!
> 
> However, they would probably appreciate it if you can run with 9.4.5
> (the latest released version).  Running it with the beta of 9.5 would be
> a bonus!
> 
> Note that I don't know enough to say for sure that later versions would
> make any difference in this case, but at least using later later
> versions would kill lots of Red Herrings!  :-)
> 

Difference between minor versions does not matter in this case. I confirmed 
the cost calculation logic regarding this problem was not changed between 
Postgres 9.4.1 and 9.4.5.

I heard there are some performance improvements on 9.5. It might change 
something regarding this problem. so I will try these queries on 9.5!

Thanks
Ryoji



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