The more I read/use non-sql databases, the more I love it.
It’s so for the OOP world and it’s easy to use, like Rails for Frameworks.
I know the disadvantages. The major concern seems to be the no-transaction and no-concurrency part. Am I correct?
Are these the only features making it hard for developers to choose to use non-sql databases entirely, even for transactions?
If these features were fixed, would it be more OK to only use document-based databases for an application?
Cause now it seems like you still have to use a RDBMS for customer billing data while your content could be in document-based databases like MongoDB/CouchDB/Cassandra.
Could someone shed a light on this.
Yes of course you can build entire applications on non-relational data models. As a general rule though most people don’t want to do that. The problem is that hierarchical/graph based data models (ie. any model that depends on navigational data structures) significantly increase the complexity and reduce the effectiveness of queries and data integrity in the database. The relational model was invented 40 years ago precisely to overcome those disadvantages inherent in navigation-based databases.