Re: Benchmark comparing PostgreSQL, MySQL and Oracle

On Fri, Feb 20, 2009 at 2:48 PM, Jonah H. Harris <jonah.harris@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