[ijoshua]

"But I think they're inherently slower for things like reporting."

I wouldn't say the deficiency is _inherent_, but the powerful indexing ability of a relational DB that we take for granted seems to be necessarily _ad hoc_ in an object-oriented DB. From my understanding, the index in an OODB is just another object in the database, which may be a B-tree, a hash table, or a simple sequential list. So far, that's fairly similar to the RDB. However, the indices in the RDB are closely coupled to the table that stores the records. The RDB "knows" that it should update the index when the table is modified. On the other hand, there isn't a table of records in the OODB, so there isn't a close coupling of the index to the data store. It may be entirely up to the application to manage the integrity of the index.