Re: gaussian distribution pgbench - Mailing list pgsql-hackers

From Fabien COELHO
Subject Re: gaussian distribution pgbench
Date
Msg-id alpine.DEB.2.10.1403030845060.20310@sto
Whole thread Raw
In response to Re: gaussian distribution pgbench  (KONDO Mitsumasa <kondo.mitsumasa@lab.ntt.co.jp>)
Responses Re: gaussian distribution pgbench
List pgsql-hackers
>>    \setrandom foo 1 10 [uniform]
>>    \setrandom foo 1 :size gaussian 3.6
>>    \setrandom foo 1 100 exponential 7.2
> It's good design. I think it will become more low overhead at part of parsing 
> in pgbench, because comparison of strings will be redeced(maybe). And I'd 
> like to remove [uniform], beacause we have to have compatibility for old 
> scripts, and random function always gets uniform distribution in common sense 
> of programming.

I just put "uniform" as an optional default, hence the brackets.

Otherwise, what I would have in mind if this would be designed from 
scratch:
  \set foo 124  \set foo "string value" (?)  \set foo :variable  \set foo 12 + :shift

And then
  \set foo uniform 1 10  \set foo gaussian 1 10 4.2  \set foo exponential 1 100 5.2

or maybe functions could be repended with something like "&uniform".
But that would be for another life:-)

> However, new grammer is little bit long in user script. It seems trade-off 
> that are visibility of scripts and user writing cost.

Yep.

-- 
Fabien.



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