Re: Benchmark comparing PostgreSQL, MySQL and Oracle

On Fri, Feb 20, 2009 at 2:48 PM, Jonah H. Harris <jonah(dot)harris(at)gmail(dot)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