DDD: All content tagged as DDD in NoSQL databases and polyglot persistence
Wednesday, 17 August 2011
CouchDB and DDD
Bradley Holt:
I’ve found CouchDB to be a great fit for domain-driven design (DDD). Specifically, CouchDB fits very well with the building block patterns and practices found within DDD. Two of these building blocks include Entities and Value Objects. Entities are objects defined by a thread of continuity and identity. A Value Object is an object that describes some characteristic or attribute but carries no concept of identity. Value objects should be treated as immutable.
Aggregates are groupings of associated Entities and Value Objects. Within an Aggregate, one member is designated as the Aggregate Root. External references are limited to only the Aggregate Root. Aggregates should follow transaction, distribution, and concurrency boundaries. Guess what else is defined by transaction, distribution, and concurrency boundaries? That’s right, JSON documents in CouchDB.
The way I read this is the impedance mismatch between the object model and the document-based model is lower than what we’ve seen in object-relational world.
Original title and link: CouchDB and DDD (©myNoSQL)
via: http://bradley-holt.com/2011/08/couchdb-and-domain-driven-design/