PostgreSQL Review

HStore is a data type in PostgreSQL database that gives the flexibility for storing sets of key/value pairs which is quite an awesome feature.

Slow count. As the number of rows exceed a couple million, the count query and queries which get to the depth of the data (like FTS) start taking too much time even with all the right indexes in place.

I've used it for two and a half years.

We use RDS Multi - AZ deployment which takes care of it all for us.

We've had no stability issues.

There have been no issues with scalability.

I've never had an issue with the product, and therefore never had to reach out.

We tried RethinkDB a couple of years back, and it was unstable at that time. Also, MySQL didn't have a JSON type back then. We switched to PostgreSQL and never looked back.

I do remember facing problems with the initial setup, but the overall documentation and SO answers has increased since then. New users face much less problem now. But there is still scope for improvement here.

I'd recommend reading Greg Smith's PostgreSQL High Performance.