Gaussian Pgbench v8 patch by Mitsumasa KONDO review & patch v9.
* The purpose of the patch is to allow a pgbench script to draw from normally distributed or exponentially distributed
integervalues instead of uniformly distributed.
This is a valuable contribution to enable pgbench to generate more realistic loads, which is seldom uniform in
practice.
* Very minor change
I have updated the patch (v9) based on Mitsumasa latest v8: - remove one spurious space in the help message.
* Compilation
The patch applies cleanly and compiles against current head.
* Check
I have checked that the aid values are skewed depending on the parameters by looking at the "aid" distribution in
the"pgbench_history" table after a run.
* Mathematical soundness
I've checked the mathematical soundness of the methods involved.
I'm fine with casting doubles to integers for having the expected distribution on integers.
Although there is a retry loop for finding a suitable, the looping probability is low thanks to the minimum
thresholdparameter required.
* Conclusion
I suggest to apply this patch which provide a useful and more realistic testing capability to pgbench.
--
Fabien.
