THE LIFECYCLE OF A SHARDED POSTGRES QUERY

Summary from the TLDR DevOps newsletter

PlanetScale's Neki router makes a sharded Postgres deployment appear as a single database by handling authentication, protocol parsing, shard-aware planning, connection pooling, and distributed execution across many Postgres nodes. Query performance depends heavily on shard-key choice: co-locating related rows can turn an expensive cross-shard join that requires scatter-gather queries and router-side hash joins into local joins executed independently on each shard.