Is there something like Redis DB, but not limited with RAM size? [closed]

Answer 1

Yes, SSDB(https://github.com/ideawu/ssdb), it has very similar APIs to Redis: http://www.ideawu.com/ssdb/docs/php/

SSDB supports hash, zset. It use leveldb as storage engine, most data is stored on disk, RAM is used for cache. On our SSDB instance with 300GB data, it only uses 800MB RAM.