Ask HN: How to Pick the Right Database?

There are so many options when picking a database, and I haven’t found anything close to a definitive guide (except MongoDB stealth marketing on Quora) on this topic.

To ask the simplest version of this question, what is the best choice of database for a read heavy, low write application?

How about a high write, low read one? Similar read and write volumes?

Is read/write latency a different consideration than throughput? How does that affect your choice?

Finally, are there benchmarks or objective comparisons I can find somewhere?

Thank you