Cassandra can be used as an alternative to Memcache for caching data from a database in order to improve performance. Cassandra offers advantages over Memcache like persistence of data, horizontal scaling, and simpler management as a single database tier rather than separate Memcache and database servers. While Memcache is faster for in-memory operations, Cassandra can serve data both from memory using caching as well as from disk, and offers different configuration options for balancing performance, consistency and fault tolerance.