Re: General purpose hashing func in pgbench

Hello Fabien,


26/01/2018 09:28, Fabien COELHO пишет:
>
> Hello Ildar,
>
> Applies, compiles, runs.
>
> I still have a few very minor comments, sorry for this (hopefully)
> last iteration from my part. I'm kind of iterative...
>
> The XML documentation source should avoid a paragraph on one very long
> line, but rather be indented like other sections.
>
> I'd propose simplify the second part:
>
>   Hash functions can be used, for example, to modify the distribution of
>   <literal>random_zipfian</literal> or
> <literal>random_exponential</literal>
>   functions in order to obtain scattered distribution.
>   Thus the following pgbench script simulates possible real world
> workload
>   typical for social media and blogging platforms where few accounts
>   generate excessive load:
>
> ->
>
>   Hash functions can be used to scatter the distribution of random
>   functions such as <literal>random_zipfian</literal> or
>   <literal>random_exponential</literal>.
>   For instance, the following pgbench script simulates possible real
>   world workload typical for social media and blogging platforms where
>   few accounts generate excessive load:
>
> Comment the Assert(0) as an internal error that cannot happen.
>
> I'd suggest to compact the execution code by declaring int64 variable
> and coerce to int in one go, like the integer bitwise functions. I'm
> in favor to keeping them in their own case and not reuse this one.
>
I did everything you mention here and attached a new version on the patch.
Thank you!

-- 
Ildar Musin
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company