You have a point, as do a lot of the other folks. However, keeping the KISS principle in mind, you can create a benchmark that simply sets up a sample database and forks off a bunch of processes to do random updates for an hour, say. Dead simple. In fact, it's so simple that I've already written the code and have it running against Postgres now. A Perl DBI script runs in a loop updating, and later prints out the number of transactions it completed in the given time frame. At the end I just tally up the numbers and I have the Will Rutherdale benchmark number for Postgres. It will give me a simple number in units of transactions per second. When I get time I'll set up an equivalent MySQL database on the same machine and run it against that. I have 'top' running in one screen and can see all the copies of my script and all the copies of postmaster and the CPU they're using. The degree to which I got excoriated just for asking the question convinced me that I was onto something and had to do it myself. -Will -----Original Message----- From: Scott Ribe [mailto:scott_ribe@xxxxxxxxxxxxxxx] Sent: 20 March 2009 11:27 To: Will Rutherdale (rutherw); pgsql-general@xxxxxxxxxxxxxx Subject: Re: Is there a meaningful benchmark? > That's why I was looking for a more balanced benchmark that exercises > said capabilities. OK, here's the thing, I will give you *one* sample issue to think about, as an illustration of the kinds of differences there are. - PostgresQL uses MVCC instead of row or page locking, which means only writer vs writer locks, which means in many situations less contention and better throughput as your concurrent load goes up. - But it also means slower count(*) and no covering indexes. (Keeping multiple versions of index pages would be too slow for many other operations, so PG has go to the table pages to check which rows are actually visible in the current transaction.) See? Overall, PG performs very well and is certainly comparable to the "big boys" on the same hardware. But the strengths & weaknesses can be *very* specific to particular queries. -- Scott Ribe scott_ribe@xxxxxxxxxxxxxxx http://www.killerbytes.com/ (303) 722-0567 voice -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
