On Fri, Feb 20, 2009 at 2:48 PM, Jonah H. Harris <jonah.har...@gmail.com>wrote:
> Having this said, the benchmark is not as unfair as you thought. I've >> taken care to prepare all databases to meet similar values for their >> cache, buffers and I/O configuration (to what's possible given their >> differences), and the I've left the rest as comes by default (for >> Oracle I've used the OLTP template). > > > Oracle's buffer cache is different than Postgres'. And there are several > other tuning paramaters which control how the buffer cache and I/O between > cache and disk is performed. Making them the same size means nothing. And, > as I said, you still didn't mention other important tuning parameters in > MySQL, Postgres, or Oracle. So either you don't know about them, or you > didn't bother to tune them, which is odd if you were trying to run a truly > comparative benchmark. > Also forgot to ask, what block size did you use in Oracle? You mentioned tuning the shared pool, but you didn't specify db_cache_size or whether you were using automatic SGA tuning. Were those not tuned? -- Jonah H. Harris, Senior DBA myYearbook.com
