throwaway204

Sure, keep the SQL. Just make it a field in a JSON POST payload, and send the results back as JSON.

The "drivers in almost every language" suck. They all suck. I've never seen a SQL driver and wire protocol that was not awful in some way. The statefulness is part of what makes them awful. We have better ways to keep track of state now.

ES grew out of Lucene, which provided an inverted index of all the text in a document, with a bunch of NLP related features bolted onto that. While ostensibly designed to be developer friendly, ES had and still has a horribly hacked together API with bugs and mis-documented misfeatures all over the place. In my experience it's anything but developer friendly. But if all you need is a text index on a document store with a static schema, it does its job reasonably well.

Mongo started as a very developer-friendly data store with lots of overstated claims to being a database. While earlier versions of Mongo were wildly dangerous to use as a business critical database, it has since matured and is now quite good at being a developer-friendly document-centric database. In my experience Mongo truly is developer-friendly as long as you don't try to use it as a full-blown transactional database with lots of complex data shapes and indexes.

I would not trust ES with anything but text search on a document store, and I would not trust Mongo with anything resembling multi-document transactions. With that said, they are both good at specific, different things.

MySQL and Postgres have their own baggage that makes them pretty terrible in some aspects. IMHO a JSON-over-HTTP API should really be table stakes for a database to be considered developer-friendly nowadays. (But please don't butcher HTTP like ES did and then claim to have that.)