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> If the hinted queries changed performance for the worse, why wouldn't you expect unhinted queries to also change for the worse after migration? The hints can
by ric2b 7y ago
> If the hinted queries changed performance for the worse, why wouldn't you expect unhinted queries to also change for the worse after migration?
The hints can introduce wrong assumptions to the planner, which can lead to worse performance than if those wrong assumptions weren't there.
- viraptor 7y agoSame with lack of hints. We're not talking about simple queries which can be expected to just work. These were previously found to be badly optimised by the first engine, so we're in unknown territory either way.