I have been greatly interested in object persistence databases like allegrocache and elephant. I work in data warehousing so my mind is greatly ingrained in the relational/dimensional model, but I was curious if others had experience with using these types of data stores in production applications. I was wondering in what problem domains one would typically use this type of a datastore. Would it make sense to look at using an object persistence model over an rdbms in areas one traditionally uses it (i.e reporting)? I'm not really interested in the downsides such as, it's hard to find people who can do that effectively, but more where the technology is and isn't useful.