Re: Postgres vr.s Oracle

On Sun, Dec 14, 2008 at 10:47 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> 10-100x?
>
> I am confused because sometimes I hear that Postgres has bad performance
> from ex-Oracle users, but in general I hear that Oracle and Postgres
> have similar performance behavior from people porting applications.

It depends on the application, whether they had tuned Oracle or not,
and whether the performance of their application was really noticeable
to begin with. Many times at EDB, we ran into people who had stock,
untuned Oracle installs. Personally, I don't think that comparing a
tuned Postgres system to an untuned Oracle system is a very fair
comparison. Though, there were a couple customer applications that
did run faster on Postgres (due to ip4r or Postgres' native
integer/floating point data types not present in the customers version
of Oracle).

The OLTP cases where Oracle starts to outperform Postgres is usually
around 25 heavy concurrent sessions. When you start scaling into
hundreds of sessions, Oracle really starts to shine. If, however,
you're running 10 or so concurrent users, Postgres will generally be
faster simply because Oracle isn't optimized for small systems. This
statement obviously varies based on what those 10 people are actually
doing, because you could likely optimize lots of things using specific
Oracle features such as materialized views, more access paths,
parallelism, etc.

Of course, if an application works equally well on both Oracle and
Postgres, I'd say go with Postgres. There's no need to pay for Oracle
features you're not going to use.

Arrg! I feel like I'm bashing on Postgres when I'm simply trying to
defend Oracle from a poorly written benchmark blog. The fact is, both
systems are good and one should choose the tool that best fits their
need, be that Oracle, Postgres, SQL Server, or (yes, even) MySQL. I
know this is the advocacy list, and my only hope was that we have a
modicum of science behind a benchmark before putting too much into it.

-Jonah