You can reimplement 95% of the "document model" with a relational database just fine, and you'll actually come out ahead given all its advantages. Unstructured

You can reimplement 95% of the "document model" with a relational database just fine, and you'll actually come out ahead given all its advantages. Unstructured documents are very rare. Querying arbitrarily against them even more so. For the fields that do need querying in a document, put them apart and add a few indexes and you're good. That's been my experience and I've been around a while.