Use Derby or DB2 for best performance?
One answer
there is a clear statement in the download pages not to use derby for anything serious. You can and should only use it for demos and for development testing or even for simple test servers. Don't use it for real work, especially since DB2 is a free download.
I have been told derby does not scale. I have no numbers, but I was told not to try to use it for production even with less than 10 users.
DB2 might require more resources e.g. a separate machine as DB server, but should be faster and more reliable provided it has the resources it needs and the connection between DB server and App server is not a bottle neck.
Comments
Thanks Ralph. The VMWare image is only to be used for demo purposes, with 1 user logged in simultaneously and only the 10 or so MTM sample users created. Based on your reply, I think it would not be worthwhile to change to DB2, if DB2 requires more resources of the VMWare.
Sandra, actually in that case I would not switch to DB2 (if you don't need RRDI).
In fact I have a small tool that I and a couple of other IBM users use to maintain backups of demo environments. It is called CLM Confiuration Manager and available on IRAM. I can not yet publish it externally, and it can only be used by IBM users so far, but it is most useful and allows to manage several versions of Derby/Tomcat based demo environments. Backup, deployment etc. is fully automated. I don't use VMWares, a backup is around 400 MB instead of GB's. The tool also allows sharing of the demo configurations and easy adjustment if you move to a different machine.
So for this usage, I always use Derby.
PS: If you see performance issue in VMWare with 4.0 you might see https://jazz.net/jazz/web/projects/Jazz%20Foundation#action=com.ibm.team.workitem.viewWorkItem&id=216290 the work item contains a work around.