Hi,

Sure that Sybase has not all the nice features Oracle
has but I'm a bit surprised that you find it way too
slow, do you have Sybase 12.5 ? 
12.5 has interesting new features compare to 11.9
version.

"20 users doing ad hoc queries ..."
I supposed you have a tool like Business Objects or
Cognos and you're hiding the tables behind a user
layer.

"Some typical queries involve joining 2 tables each
holding 2 Million rows."
Are you using dimensionnal modeling ? You can have a
dimension with a million lines but it's very rare.

Have you built aggregates ?
The only good way to speed up queries in a DW is to
pre-calculate the data.

Have you investigate to see what is the bottleneck in
your application ?
Depending on it you may or may not solve it by using
Oracle DW features : partitionnning, star join, ,...


HTH

 --- "Sackwitz, Antje" <[EMAIL PROTECTED]> a
�crit�: > > Hi, Stephane,
> > actually we have the database running on Sybase
> but there it is way too
> > slow ( as  I 
> > told everyone here before). The application has
> about 25 small and about
> > 10 large 
> > tables. Data comes in every night about 100-250MB.
> We have just about 20
> > users 
> > doing  'ad hoc' queries to the database via a
> commercial tool.  At the
> > moment we 
> > have a test installation running on an IBM
> computer having 2 processors a
> > 2Ghz, 2 
> > Gig RAM. Some typical queries involove joing 2
> tables each holding
> > 2Million rows.
> > Test situation will represent data warehouse after
> being 3 years in
> > production.
> > Well, now the query takes about 15-20 Mintues
> which is too slow for our
> > sales 
> > people. I calculated, the machine scans about
> 800000-1Mio rows per second.
> > I thought, there are a lot of tuning possibilites
> in Oracle that are not
> > available in 
> > Sybase. Our system can run on both RDBMS. So as we
> are buying a new
> > machine 
> > for our database test environment I thought  I
> better find out which is
> > best equipment 
> > for Oracle as I expect people to learn that Sybase
> is not your number one
> > when you 
> > go for a fdata warehouse. Overall we calculated,
> that we add new muodules
> > over 
> > next couple of years so finally DW will hold 20
> Gig data.
> > Windows is chosen as sales folk here says Windows
> machines are a lot
> > cheaper 
> > than UNIX and the commercial tool needs some
> server processes available
> > not for 
> > Linux....
> > Any further recommendations?
> > Regards,
> > Antje
> -- 
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> -- 
> Author: Sackwitz, Antje
>   INET: [EMAIL PROTECTED]
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=====
St�phane Paquette
DBA Oracle, consultant entrep�t de donn�es
Oracle DBA, datawarehouse consultant
[EMAIL PROTECTED]

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