On 03/17/2014 10:40 AM, KONDO Mitsumasa wrote:
By the way, you seem to want to remove --gaussian=NUM and --exponential=NUM command options. Can you tell me the objective reason? I think pgbench is the benchmark test on PostgreSQL and default benchmark is TPC-B-like benchmark. It is written in documents, and default benchmark wasn't changed by my patch. So we need not remove command options, and they are one of the variety of benchmark options. Maybe you have something misunderstanding about my patch...
There is an infinite number of variants of the TPC-B test that we could include in pgbench. If we start adding every one of them, we're quickly going to have hundreds of options to choose the workload. I'd like to keep pgbench simple. These two new test variants, gaussian and exponential, are not that special that they'd deserve to be included in the program itself.
pgbench already has a mechanism for running custom scripts, in which you can specify whatever workload you want. Let's use that. If it's missing something you need to specify the workload you want, let's enhance the script language.
The features we're missing, which makes it difficult to write the gaussian and exponential variants as custom scripts, is the capability to create random numbers with a non-uniform distribution. That's the feature we should include in pgbench.
(Actually, you could do the Box-Muller transformation as part of the query, to convert the uniform random variable to a gaussian one. Then you wouldn't need any changes to pgbench. But I agree that "\setrandom ... gaussian" would be quite handy)
- Heikki -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
