Re: Benchmark comparing PostgreSQL, MySQL and Oracle

On Fri, Feb 20, 2009 at 2:35 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> > First of all, you need to do some research on the benchmark kit itself,
> > rather than blindly downloading and using one. BenchmarkSQL has
> significant
> > bugs in it which affect the result. I can say that authoritatively as I
> > worked on/with it for quite awhile. Don't trust any result that comes
> from
> > BenchmarkSQL. If you fix the bugs, Oracle (out of the box in OLTP
> config)
> > will come out 60%.
>
> 60% what?

Faster than PG 8.3-dev with 100 warehouses (when I last tested it).

> > Oracle comes out twice as fast as PG on Linux. And, unless you're using
> a
> > significant number of warehouses, MySQL+InnoDB will come out better than
> PG
> > as well.
>
> I can believe that MySQL could come out faster than PG because I've
> had previous experience with it being blindingly fast. Of course I've
> also had experience with it having amazingly poor data integrity.

That was MySQL+InnoDB. I haven't really had any integrity problems in that
configuration.

> I would be pretty surprised if Oracle were in general twice as fast as
> PG - what are they doing that much better than what we're doing? I
> could certainly imagine it being true in cases that rely on specific
> features we lack (e.g. join removal)?

DIO + AIO + multiple DBWR processes + large buffer cache + properly sized
logs/log buffers makes a big difference. There are also several other
concurrency-related tunables which contribute to it as well.

--
Jonah H. Harris, Senior DBA
myYearbook.com