For what it's worth, postgresql supports intervals (ranges) as of 9.1. http://www.postgresql.org/docs/9.2/static/rangetypes.html

There's also a fantastic ip4r extension for postgresql that lets you efficiently query IP ranges (which the article says was the motivation for adding interval sets to redis).

I use it for storing maxmind's IP database to figure out where our visitors come from in SQL queries -- given an IP address, I can find the city. zip code, lat/lon, etc. Which lets me easily figure out things like "what percentage of our users that purchased something this year are in this particular UPS shipping zone?"

This is a dupe of a post a long time ago, but if you haven't read it, it's a great read and shows how well-architected Redis is.

Original thread: http://news.ycombinator.com/item?id=5663727