I love the document record pattern. I use this on google app engine, which is a tad tricky to use as a relational db. It actually ends up being way simpler and faster. For instance, you can model an app with just one "table" (Kind). You can put say a user id primary key, then have blob binary data fields which store your serialized document records. The reason it's so fast is all you're doing is a simple index scan to lookup all the data you want. It also makes it really simple to store items into memcached/memcache.