Johannes Ernst has a blog post of notes from a presentation by Dan Pritchett and Randy Shoup of eBay, where they discuss the architecture of their huge high-volume system. Some interesting highlights:
- They use no stored procedures and very simple triggers in their databases.
- All of the intensive data handling such as referential integrity, joins and sorting are handled in the application layer! rather than in the database. They figure that application servers are cheaper, and databases are the bottleneck. (That may be because they're using Oracle, though)
- They use J2EE, but only for the database connection and such, nothing else.
So next time people try to sell you on the 'Enterprise' features of J2EE, remember that eBay doesn't even use them.