[SiVal]

Somewhat similar to the difference between C/C++ or enterprise Java and various dynamic or "scripting" languages in terms of structure, the "S" in SQL or NoSQL. The former tends to require more up-front structural design to do anything, which is a nuisance at first when you're not sure what you will end up needing. The latter tends to be quicker to throw together and repeatedly rearrange in the early days of its evolution, which is a huge advantage to a small startup trying to figure out what business it's in, but often runs into trouble later, once the needs have stabilized and the structure becomes more of a benefit than a cost.

For areas other than structure, the difference can be more like the difference between a general purpose programming language and a domain-specific language. SQL databases are general purpose, so they offer a large, nicely integrated package of features, while NoSQL databases often sacrifice some of those features to optimize for some niche. From this perspective, the SQL database can be the best choice for a startup trying to find its niche with the NoSQL chosen as an optimization once that niche has been identified.

The fact that a new business can't be sure what its business will end up being is an argument both for and against using a SQL database.