Re: gaussian distribution pgbench

> Please find attached 2 patches, which are a split of the patch discussed in 
> this thread.

Please find attached a very minor improvement to apply a code (variable 
name) simplification directly in patch A so as to avoid a change in patch 
B. The cumulated patch is the same as previous.

> (A) add gaussian & exponential options to pgbench \setrandom
>    the patch includes sql test files.
>
> There is no change in the *code* from previous already reviewed submissions, 
> so I do not think that it needs another review on that account.
>
> However I have (yet again) reworked the *documentation* (for Andres Freund & 
> Robert Haas), in particular both descriptions now follow the same structure 
> (introduction, formula, intuition, rule of thumb and constraint). I have 
> differentiated the concept and the option by putting the later in <literal> 
> tags, and added a link to the corresponding wikipedia pages.
>
>
> Please bear in mind that:
> 1. English is not my native language.
> 2. this is not easy reading... this is maths, to read slowly:-)
> 3. word smithing contributions are welcome.
>
> I assume somehow that a user interested in gaussian & exponential 
> distributions must know a little bit about probabilities...
>
>
>
> (B) add pgbench test variants with gauss & exponential.
>
> I have reworked the patch so as to avoid copy pasting the 3 test cases, as 
> requested by Andres Freund, thus this is new, although quite simple, code. I 
> have also added explanations in the documentation about how to interpret the 
> "decile" outputs, so as to hopefully address Robert Haas comments.

-- 
Fabien.