Re: PostgreSQL vs. Oracle vs. Microsoft

Randolf Richardson wrote:
>         I'm looking for recent performance statistics on PostgreSQL vs. Oracle
> vs. Microsoft SQL Server.  Recently someone has been trying to convince my
> client to switch from SyBASE to Microsoft SQL Server (they originally wanted
> to go with Oracle but have since fallen in love with Microsoft).  All this
> time I've been recommending PostgreSQL for cost and stability (my own testing
> has shown it to be better at handling abnormal shutdowns and using fewer
> system resources) in addition to true cross-platform compatibility.
>

I'm not sure that you are going to get a simple answer to this one. It
really depends on what you are trying to do. The only way you will know
for sure what the performance of PostgreSQL is is to try it with samples
of your common queries, updates etc.

I have recently ported a moderately complex database from MS SQLServer
to Postgres with reasonable success. 70% selects, 20% updates, 10%
insert/deletes. I had to do a fair bit of work to get the best
performance out of Postgres, but most of the SQL has as good or better
performance then SQLServer. There are still areas where SQLServer
outperforms Postgres. For me these tend to be the larger SQL Statements
with correlated subqueries. SQLServer tends to optimise them better a
lot of the time. Updates tend to be a fair bit faster on SQLServer too,
this may be MS taking advantage of Windows specific optimisations in the
filesystem.

I did give Oracle a try out of curiosity. I never considered it
seriously because of the cost. The majority of my SQL was *slower* under
Oracle than SQLServer. I spent some time with it and did get good
performance, but it took a *lot* of work tuning to Oracle specific ways
of doing things.

My Summary:

SQLServer: A good all round database, fast, stable. Moderately expensive
to buy, cheap and easy to work with and program for (on Windows)

PostgreSQL: A good all rounder, fast most of the time, stable. Free to
acquire, more expensive to work with and program for. Client drivers may
be problematic depending on platform and programming language. Needs
more work than SQLServer to get the best out of it. Improving all the
time and worth serious consideration.

Oracle: A bit of a monstrosity. Can be very fast with a lot of work,
can't comment on stability but I guess it's pretty good. Very expensive
to acquire and work with. Well supported server and clients.

Cheers,
Gary.