Backend & systems·Caching and invalidation
every write goes into the cache and the database in the same call, so the cached copy is never behind the row.
Write-through cache
Writes are applied to the cache and the backing store synchronously before the call returns. It keeps the cache consistent with the store and makes subsequent reads cheap, at the cost of adding the cache write to every write's latency. It also caches things nobody will read, which on a write-heavy table is pure waste.