The aggregate boundary is not a modelling preference — it is the answer to which invariants must hold at every instant, and everything else can be eventually consistent.…
It means unlimited, and it is fine on a development site with forty posts. The site it eventually runs on has forty thousand. fields => ‘ids’ changes the…
Expand-migrate-contract is correct and takes three releases, which is two weeks on a fortnightly cadence — and occasionally the change cannot wait that long. A multi-table RENAME is…
Seconds_Behind_Master reports how far behind the SQL thread is on the events it has received, which is not the same as how stale the data is. The long-ALTER…
Truncating every table between tests costs a statement per table per test; a transaction and a rollback is one of each. The second-connection case produces a genuinely confusing…
The optimiser chooses a plan from statistics it samples, and a table whose distribution has changed since the last sample gets a plan chosen for the old data.…
8.0 changed the default collation, and a table created after an upgrade sorts differently from one converted before it — silently, and in a way that only shows…