(2014/03/17 22:37), Tom Lane wrote: > KONDO Mitsumasa <kondo.mitsum...@lab.ntt.co.jp> writes: >> (2014/03/17 18:02), Heikki Linnakangas wrote: >>> On 03/17/2014 10:40 AM, KONDO Mitsumasa wrote: >>> 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. > >> Well, I add only two options, and they are major distribution that are seen >> in >> real database system than uniform distiribution. I'm afraid, I think you are >> too >> worried and it will not be added hundreds of options. And pgbench is still >> simple. > > FWIW, I concur with Heikki on this. Adding new versions of \setrandom is > useful functionality. Embedding them in the "standard" test is not, > because that just makes it (even) less standard. And pgbench has too darn > many switches already. Hmm, I cooled down and see the pgbench option. I can understand his arguments, there are many sitches already and it will become more largear options unless we stop adding new option. However, I think that the man who added the option in the past thought the option will be useful for PostgreSQL performance improvement. But now, they are disturb the new option such like my feature which can create more real system benchmark distribution. I think it is very unfortunate and also tending to stop progress of improvement of PostgreSQL performance, not only pgbench. And if we remove command line option, I think new feature will tend to reject. It is not also good.
By the way, if we remove command line option, it is difficult to understand distirbution of gaussian, because threshold parameter is very sensitive and it is also very useful feature. It is difficult and taking labor that analyzing and visualization pgbench_history using SQL. What do you think about this problem? This is not disscussed yet. > [mitsu-ko@pg-rex31 pgbench]$ ./pgbench --gaussian=2 > ~ > access probability of top 20%, 10% and 5% records: 0.32566 0.16608 0.08345 > ~ > [mitsu-ko@pg-rex31 pgbench]$ ./pgbench --gaussian=4 > ~ > access probability of top 20%, 10% and 5% records: 0.57633 0.31086 0.15853 > ~ > [mitsu-ko@pg-rex31 pgbench]$ ./pgbench --gaussian=10 > ~ > access probability of top 20%, 10% and 5% records: 0.95450 0.68269 0.38292 > ~ Regards, -- Mitsumasa KONDO NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
