Notes on how data is structured, stored, and read efficiently.
Capture only what you need — collect the minimum data necessary, no more.
Notes
Normalisation
Organising data to remove redundancy so each fact lives in exactly one place — and the trade-offs against denormalising for read performance.
Database Sharding
Splitting a database horizontally across servers to scale writes and reads beyond a single machine.
Indexes and Query Planning
An index is a suggestion to the query optimizer, not a guarantee — the execution plan is the decision.
N+1 Queries and Batching
A loop around a remote call costs one round trip per item; batch the keys and ask once.