Hello Robert,

Sure, and I would have looked at that patch and complained that you
were implementing a modulo operator with different semantics than C.
And then we'd be right back where we are now.


To be clear about my intent, which is a summary of what you already know: I would like to be able to generate a reasonable non uniform throttled workload with pgbench.

I do think such a feature is worth having for anybody who would like to do something realistic with pgbench, and that it is in the "general interest" of postgresql to have such features.

In particular, given the current state of abysmal performance under some trivial load with pg, I really think that it is really worth having a better tool, and I think that my effort with rate and progress helped to put these hidden problems into the light, and I do hope that they are going to be solved quickly.

Now if I submitted a big patch with all the necessary features in it, someone would ask to break it into pieces. So they are submitted one by one (progress, throttling, limit, modulo, ...).

Note I did not start with the non uniform stuff, but Mitsumasa-san sent a gaussian distribution patch and I jumped onto the wagon to complement it with an exponential distribution patch. I knew when doing it that is was not enough, but as I said "one piece at a time", given the effort required to pass simple patch.

What is still needed for the overall purpose is the ability to scatter the distribution. This is really:

 (1) a positive remainder modulo, which is the trivial patch under

 (2) a fast but good quality for the purpose hash function
     also a rather small patch, not submitted yet.

 (3) maybe the '|' operator to do a TP*-like non-uniform load,
     which is really periodic so I do not like it.
     a trivial patch, not submitted yet.

If you do not want one of these pieces (1 & 2), basically the interest of gaussian/exponential addition is much reduced, and this is just a half baked effort aborted because you did not want what was required to make it useful. Well, I can only disagree, but you are a committer and I'm not!


Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:

Reply via email to