[sjwright]

Sorry, but hard disagree. For all the failings of SQL systems, they work staggeringly well 99% of the time as long as the operator understands how they work. No-SQL systems do have their place, but all too often their choice stems from a failure to understand SQL-based databases. (And the hard truth: unless you’re doing something especially novel there’s a lot less difference between map/reduce and a bog standard table index than no-SQL proponents would have you believe.)

In my estimation, if you're not already intimately familiar with the intricacies of performant SQL, chances are you're not playing in a space where a no-SQL architecture is an appropriate fit anyway. And you're certainly not in a position to make an informed decision between SQL and no-SQL. It's a much better use of this hypothetical person's time to set up Mariadb or Sqlite and do a deep dive into the fundamentals query performance.

[m_mueller]

Just to clarify: I'm not saying there is a significant difference between map views and indices, I'm saying I prefer the directness of programming with them over trusting the query planner and table statistics. In couch, to do a table scan, I need to program it as such, otherwise I'm forced to use a view - things like forgotten indices for some edge cases are impossible. Sure takes longer to do things, but when performance issues arise it's easy to reason about while with SQL based DBs I've seen a lot of time being spent at that stage. They work well 99%, and then that remaining 1% takes 99% of your time.