For InnoDB, OPTIMIZE TABLE is mapped to an ALTER TABLE … FORCE, which copies the whole table. The friendly name is the problem: it sounds like a maintenance…
The default flushes and syncs the log on every commit, which is the only setting that survives an operating system crash without losing transactions. Setting this to 2…
A deletion request arrives and the first question is where the data is, which is not a question anybody can answer from memory. The reason field is what…
Every autoloaded option is fetched and unserialised on every request, and a plugin storing a large structure in one turns a cache into a fixed cost. Tracking the…
MySQL 5.7 parses a CHECK constraint, stores it and never evaluates it, which is worse than rejecting it. A constraint that exists and does nothing is the worst…
A shared database with a single application user has no boundaries at all, whatever the code layout suggests. Separating the migration user from the application user is the…
Swapping a database’s buffer pool to disk turns a memory pressure problem into a latency problem that is much harder to diagnose. Setting swappiness to 1 rather than…