2.8 Rankings and Time Indexed Data

Five players are on the board: eve with 50 points, alice with 100, carol with 150, and bob and dave with 200 each. The previous lesson built that leaderboard and showed how a sorted set keeps it in order: a skip list and a hash table for large sets, a listpack for small ones, O(log N) for updates and ranks, and ZRANGE with BYSCORE, REV, and LIMIT for reads.

This lesson uses those commands for two families of designs. The first is rankings, from a basic leaderboard to ties, periodic boards, and very large boards