Splitting data across servers Day 121 of 149 👉 Full deep-dive with code examples The Library Card Catalog Analogy One huge card catalog is hard to use: Long lines at one catalog If it breaks, no one can find books Split by letters: A-F catalog in room 1 G-M catalog in room 2 N-Z catalog in room 3 Search is faster, and if one catalog goes down, you can still use the others (but you lose access to that section until it comes back). Sharding splits your database into pieces across servers! Why Shard? One server has limits: Storage → Runs out of disk space Speed → Too many queries to handle Memory → Can't fit all data in RAM Sharding spreads the load across multiple servers. How It Works Split data by some key: Users A-H → Server 1 Users I-P → Server 2 Users Q-Z → Server 3 Enter fullscreen mode Exit fullscreen mode Each piece is a "shard." Each shard handles its portion.…