David.Poole (9/21/2014)

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Microsoft DocumentDB looks interesting but is only available in Azure. I'd love to know where the graph database outlined in the Trinity white paper is going to go.

I have some qualms about the scalability capability of NOSQL vs RDBMS. There is a scale point beyond which you cannot go with SQL Server. It is fundamental to the balance of the compromises that have to be made to make an RDBMS work. NOSQL allows a choice to be made to choose to discard or downgrade certain features in order to upweight others. Consider performance as an example, to obtain it we can discard schema enforcement , durability, consistency and a whole raft of other things.

I have a number of concerns with this

• Is there sufficient understanding in what is being traded to gain performance and alleged flexibility
• Is there a realistic sizing and capacity evaluation. Incumbent Tech A is 100x better than we need, Tech B is 1000x better than we need. Why go through the headache and heartache of adopting Tech B?
• Let us suppose you swap out a RDBMS for a document store. Swapping two technologies in a system means that the business has what they had before and not necessarily a step forward....yet. It is a promise of jam tomorrow

I am not sure how many performance issues are down to the DB platform and how many are down to coding problems. Will a tech swap end up enabling a "throw hardware at it" mentality to performance issues?

If I was a business startup I absolutely would try NOSQL first, either Couchbase or MongoDB for document store, REDIS for session state, Elastic Search as part of the ELK stack for log handling and search, NEO4J for graph capability.

In an existing enterprise I think certain NOSQL solutions offer compelling cases for their use. I'm not convinced that an argument for wholesale or majority abandonment of RDBMS stacks up. In an enterprise situation data has to flow between systems. Quite a few NOSQL solutions seem focussed on serving one particular system and not so much on system to system integration.