The optimization trick is outlined here: http://redis.io/topics/memory-optimization http://redis.io/topics/memory-optimization If your sets and zsets are boun

The optimization trick is outlined here: http://redis.io/topics/memory-optimization http://redis.io/topics/memory-optimization If your sets and zsets are bounded within a certain limit then they will be compressed and take up quite a bit less space. Updating your configuration obviously requires a restart so that will need to be kept in mind (ie: if your data fragmentation is high then restarting will eliminate the fragmentation, so space savings will be apparent but they're not actually indicative of any changes).