Re: [PLUG] Can Open Source Replace Oracle?

["William H. Magill" <magill@mcgillsociety.org>]

On Thursday, April 10, 2003, at 04:51  PM, gabriel rosenkoetter wrote:
> On Wed, Apr 09, 2003 at 09:52:47PM -0400, Chris Hedemark wrote:
> > production systems that currently run against PostgreSQL.  If
> > PostgreSQL is going to eat with the dogs for its poor performance, at
> > least it should be because of true product suckage and not poor
> > configuration.
>
> Postgres's poor performance isn't just a tuning issue. In fact, it's
> mostly not a tuning issue. It's mostly a (historical, don't know if
> it's still the case) completely braindamaged (lack of) optimization
> of SQL statements. Oracle kicks everything else's ass at doing this.
>
> Postgres sucks worse than sapdb, last I heard, for the kinds of
> queries Barry describes. I'd be glad to know that wasn't true any
> more... but if it is, no amount of SHMMAX tweaking is going to fix
> the underlying lack of code optimization. It'd be like building
> everything in a system statically with -O0 with gcc targeting a
> 64-bit, big-endian architecture. Performance would suck no matter
> how many cycles you ran the processor at.

I don't know Postgres, but back in the days when there was Ingres and 
Oracle, (10+ years ago) there were some very significant design 
differences between the two data base engines.

Ingres was optimized (and I do mean optimized) to handle small 
databases... on the order of megabytes of data.  Oracle on the other 
hand was optimized to handle gigabytes of data. Ingres grew out of the 
original database engine that was used as a teaching tool as part of 
BSD. It had a very different reason for existing than did Oracle.

There are some significant issues effecting performance which relate to 
the way in which a database is updated and accessed (nominally 
sequential access vs random access). Historically, one could optimize 
performance to be fast at one or the other, but not both. If you shot 
for both, you got mediocre performance in both operations. The Oracle 
engine design tackled this problem and made significant improvements in 
the art.

There used to be some Computer Science white papers floating around 
that analyzed the differences between the two. There were two 
performance curves, both essentially knee curves. One which showed 
Ingress with good performance up to a point and then falling off 
rapidly, and the other almost an mirror image, showing Oracle with 
lousy performance up to a point, and then shooting up dramatically.

Granted, that was then and this is now, and both engines have been 
completely re-written since that time (at least twice.) However, I 
don't know if they have been re-designed.

People like to dump on Ellison and Oracle, but the fact is, Oracle 
represented a significant improvement at the time. That was how they 
captured the market, it WAS a better mousetrap. Today, that may or may 
not still be true. However, I suspect that it is. (One "feature," which 
I know Oracle has which Postgres does not have is the Digital/Compaq 
Tru64 Unix/VMS cluster technology. This was licensed for 9iRAC.)

T.T.F.N.
William H. Magill
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magill@mcgillsociety.org
magill@acm.org
magill@mac.com

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