Re: Re: pgbench - add pseudo-random permutation function - Mailing list pgsql-hackers

From David Steele
Subject Re: Re: pgbench - add pseudo-random permutation function
Date
Msg-id be567349-f2ea-436f-faf0-bb5cc3b01c4a@pgmasters.net
Whole thread Raw
In response to Re: pgbench - add pseudo-random permutation function  (Fabien COELHO <coelho@cri.ensmp.fr>)
Responses Re: pgbench - add pseudo-random permutation function
List pgsql-hackers
Hi Hironobu,

On 3/3/19 12:55 PM, Fabien COELHO wrote:
> 
>> Indeed, the patch needs a rebase & conflit resolution. I'll do it. Later.
> 
> Here is an update:
> 
>   - take advantage of pg_bitutils (although I noted that the "slow"
>     popcount there could be speeded-up and shorten with a bitwise operator
>     implementation that I just removed from pgbench).
> 
>   - add comments about the bijective transformations in the code.
> 
> As already stated, this function makes sense for people who want to test 
> performance with pgbench using non uniform rands. If you do not want to 
> do that, you will probably find the function pretty useless. I can't 
> help it.
> 
> Also, non uniform rands is also a way to test pg lock contention behavior.

You have signed up as a reviewer for this patch.  Do you know when 
you'll have time to do the review?

Regards,
-- 
-David
david@pgmasters.net


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