How do you expire a field of a hash in Redis?

Question

I'd like to expires certain field of a hash after different amount of time. From the documentation it doesn't look to be possible: http://redis.io/commands/expire . Can I emulate this behavior somehow? Currently I'm just copying the hash name to be a prefix of all of its fields and adding expires to each. For the structure I'd like to store is:

"PEOPLE" : {
 "NICK" : 29
 "AMANDA" : 23
}

but I can't set an expire on "NICK", only on the whole hash "PEOPLE". So I convert it to and number of key, values:

"PEOPLE_NICK" : 29 (expire 2 hours)
"PEOPLE_AMANDA" 23 (expire 1 hour)

but there are many keys and it makes it very difficult to manage and more tedious to fetch as I have to fetch everything by the common prefix.

Answer 1

If the above example is an accurate representation, and depending on how exactly you'll consume the data, you could use a sorted set with the score of each person be a Unix timestamp. Then you'd use zremrangebyscore on an Cron job to clean out items which are beyond you acceptable window.