TopK is now Generally Available

Leaderboards, activity feeds, top-rated products. Most applications have at least a few queries that ask for the best K rows out of a large set.

Readyset has always been able to cache those queries. With TopK, it now does so much more efficiently by storing only the top K rows per key instead of every matching row.

TopK is now generally available. The new approach reduces memory usage by several orders of magnitude, keeps more keys resident in cache, and eliminates post-processing overhead on every read.

No application changes. No new flags. If your cached queries have the right shape, Readyset starts using the TopK operator automatically when you upgrade.

The full post covers what changed, how the buffer tuning works, and when to touch the defaults.