I'm not sure how to efficiently implement redis-style sorted sets using SQL, but the fact that I have to think about it at all means it's easier to use redis.

I'm not sure how to efficiently implement redis-style sorted sets using SQL, but the fact that I have to think about it at all means it's easier to use redis. A lot of the other things could probably be done with the right combination of stored procedures and clever SQL but again, redis makes it so much easier as to make things qualitatively different. It's just a bunch of C files with no real external dependencies (I don't even have to run ./configure before building it!). Operationally, for a generic non-db-expert kind of person like me, redis is much simpler to manage than PostgreSQL. With redis I don't need to worry about vacuuming, write ahead logs, archiving, query tuning & statistics, lock management, etc (to name a few things from the config file).