Write amplification.
also: read amplificationOne logical write causing many physical or downstream writes, such as one post fanned out to millions of feeds.
the two-minute refresher
- Feeds: one post → N follower-feed writes.
- Storage: LSM compaction rewrites data several times.
- Read amplification is the mirror image: one read triggering many reads.
- Every design trades one for the other; pick by your read/write ratio.