We have been using Alfresco over Oracle for the past year. We have performance issues, and we only have a few thousand documents loaded (mostly PDF and HTML). Simple operations like keyword queries take several seconds when they ought to take milliseconds.
We're currently investigating the potential causes of these performance issues, and one possible culprit is that perhaps the Alfresco DB schema isn't tuned as well for Oracle as it is for MySQL. For example with Alfresco 1.3.X, there were oracle FK indexes that were completely missing, and we had to run a custom script to generate them. Also, MySQL is known to be faster for certain types of operations than Oracle due to the fact that it's more lightweight. We also suspect the RDBMS platform because we have done other things that would make the system performant, such as moving indexes onto a fast local drive, making sure caching is turned on, etc. Our colleagues in another group have been using Alfresco as long as we have, but they've deployed it on top of MySQL on lesser hardware, loaded tens of thousands of documents, and get lightening fast performance.
FWIW, that's been my experience, and I'm currently trying to get Alfresco up and running with MySQL to see if it makes a difference. There could be other factors involved that I'm not aware of, and it would be nice to hear from one of the alfresco engineers as to the level of performance tuning for Oracle vs. MySQL…
