On Thu, 2003-01-09 at 14:02, Matthew Baird wrote: > so you are promoting using what?
No promotion I am afraid, merely an observation. Comparing CMP with persistent object frameworks is not really a fair comparison. Comparisons are odourous as Shakespeare once wrote. :-) In my mind, it is like comparing Macromedia Flash with HTML. Similar results can be achieved with both technologies, but their design philosophies are totally different. The confusion is that people assume CMP must map to a relational database through JDBC. This is not the case, CMP was designed to be an abstract concept handled by the EJB container. The confusion has no doubt been increased by the fact that relational mappings are by far the most common way of doing CMP. CMP could be implemented using flat files, or an XML file as other examples. I believe I read somewhere that JBoss 4.0 will make it much easier to have different CMP implementations. > Do you have an example of: > > Your code -> datastore That's an easy one. SQL is more or less an example of this. The code you write in SQL interacts directly with the datastore (ignoring transport and compilation issues). Similarly, I could see a technology where CMP takes the place of SQL and the concept of rows and tables vanishes completely. CMP would probably even have the edge over SQL, because most of the queries (finders and friends) could be compiled at deployment time whereas SQL is generally compiled on the fly. Additionally, indices could be automatically calculated. Getting back to the subject of the thread, I would say that in performance terms it seems likely that light-weight persistent object frameworks will out match CMP frameworks doing O/R mappings. However this is not a limitation of CMP, only the current implementations of it. It should be possible to have a CMP implementation that can outperform even raw JDBC. Writing a CMP application will give you the option of being able to upgrade it to more advanced technology later without code changes. A reliable, transactional, clusterable, native CMP store would rock. If it came with some supporting tools (such as a shell for doing ad-hoc operations) then it would eliminate the need for a relational database at all in many applications (including mine). -- Peter Beck BEng (hons) - Managing Director, Electrostrata Ltd. http://www.electrostrata.com --+-+-- Experts in e-business and e-commerce ------------------------------------------------------- This SF.NET email is sponsored by: SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! http://www.vasoftware.com _______________________________________________ JBoss-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-user
