Track · 2:30 · Liner note
TTL, or Time to Lounge
TTL, time to live, is a rule that automatically deletes or moves data after a set period, which bounds storage cost and helps meet retention policies.
Data does not have to live forever. A TTL, time to live, tells the system to delete or move rows after a set period, so storage stays bounded without anyone writing a cleanup job. TTL, or Time to Lounge, is the retirement party: the rows did their work, and now they rest.
Set it from a retention policy, not a hunch. In some engines, ClickHouse included, expiry is applied during background merges, so rows can outlive their deadline briefly. Test on a copy first, since an eager TTL on the wrong column is an efficient way to lose data.