[pas]

It's a trade off between updates per sec and latency.

Maybe simply using a timeout per job type is a better way. (That of course trades off simplicity.)

[shrimpx]

I agree. Frequency of updates also becomes more of an issue as you add workers. Say you have 1000 workers each updating every 2 seconds. That's ~500 timestamp update statements per second which is not trivial in terms of added load on the DB.