Sharding

As relational databases grow beyond millions to billions of rows, single-table query performance degrades due to massive B-Tree index sizes and memory swapping.…

A multi-tenant analytics platform partitions incoming events by tenant_id, hashed onto 16 shards — a design that looked perfectly balanced in every load test. T…

A team says "we need to shard the database" when the actual measured problem is a 200GB events table that scans slowly, or "let's add replication" when what the…