What do you have in mind? This is extremely vague.
I have already an existing database structure which is built similarly to orchard:
I got products (aka ContentItem in Orchard) and their properties.
All properties are stored in one table with a relation to the product. The properties of a product are also defined by a product type (aka Content Type).
Every ContentPartRecord would be a ContentType with it's properties and every ContentType would be a bunch of ContentPartRecords and the Fields on the ContentItem itself.
The very huge difference is that we wouldn't have a table per model, but one table with all properties.
All other models could be as tables in the database, but the content Items and it's part records and fields in our already existing structure.
Thank you very much for your commitment.