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Re: ozone & modularity

On Tue, 6 Feb 2001 03:07:34 +0100
Andreas Monitzer <a@blackbox.net> wrote:
> On Monday, February 5, 2001, at 05:05 PM, Falko Braeutigam wrote:
> > 200 RMI calls per mouse click are indeed to slow. This issue has been
> discussed 
> > several times here on the list. In my opinion the Lightweight Objects
> (see 
> > http://ozone-db.org/ozone-users/11-2000/msg00141.html ff.) are the
> best 
> > approach 
> > to display database objects in the GUI (tree, list, etc.) 
> I've now implemented it (took me two days of debugging %-( ), but the
> problem is still there:
> Reading the list takes forever, but display is now ok.
> I integrated some simple profiling code, and the results are the
> following:
> 92 objects
> Time to read object from database: 0.4-0.8 sec (= 1.25-2.5 obj per sec)
> Time for further processing: 0.05 sec
> Total time: 77 sec
> Which is rather slow for a 300MHz G3. A regular database would get about
> 1000 entries per sec, not 2...

Sounds like your'e querying your objects one by one (get member of object
1, get member of object 2,...) from the client side. This is of course
slow (like Falko said, discussed multiple times), because each Ozone
object access from client side is a RMI (each inluding the overhead added
by Ozone for e.g. the transactional environement).

If you query a relational database (I think this is what you mean with a
'regular' database) you don't do it like that. Mostly you have _one_ query
and get a set of entries matching the query. You get your result with only
_one_ database call.

This is somewhat similar to the Lightweight Objects approach discussed in
<http://ozone-db.org/ozone-users/11-2000/msg00141.html>. You really should
read this mail and the discussion that followed.

Conny Krappatsch

Conny Krappatsch                              mailto:conny@smb-tec.com
SMB GmbH                                        http://www.smb-tec.com