I am planning and researching my switch from MySQL to MongoDB right now and I just had an interesting thought... I have a bunch of hierarchical objects that I need to store in the database. My current method is to have a bunch of embedded documents in a collection. They will never need to be searched for. Would it possibly make sense just to serialize the PHP objects, stick them in the DB, and then unserialize them back into PHP objects when I want to use them? The alternative is using Doctrine as my ORM.

My programming intuition tells me that this is bad design and is limiting, but I feel like serializing and unserializing would be very fast and eliminate the need for an ORM.

What's your opinion? Good design or bad design?