Comparison
NormalisationvsNormalised state
Normalisation
you store the customer's address in exactly one table so that changing it cannot leave four stale copies behind.
Structuring tables so each fact is stored once, with relationships expressed by keys rather than repetition. It makes writes correct by construction: there is no second copy to forget. The cost is joins on the read path, which is why every normalised schema eventually meets a report that needs six of them.
Full entry →Normalised state
you store each record once by id and keep lists as arrays of ids rather than nested copies.
Flattening client-side data into a lookup table keyed by identifier, with relationships expressed as ids. It means an update touches one place rather than every list the record appears in, which is what makes editing a shared entity behave. The cost is indirection at read time and a good deal of ceremony, which is why per-query caching has largely replaced it for server data.
Full entry →