Even if you are doing this with redis, there are two far better methods of doing it - with lexical ranges, or with RediSearch's autocomplete, which is way more

Even if you are doing this with redis, there are two far better methods of doing it - with lexical ranges, or with RediSearch's autocomplete, which is way more powerful - uses a compact trie, has fuzzy matching with a Levenshtein automaton, scoring, payloads, etc. See http://redisearch.io/Commands/#ftsugget http://redisearch.io/Commands/#ftsugget (Full disclosure: I'm the author of that project)