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> The basic promise of a query optimizer is that it picks a good plan most of the time and does it quickly and efficiently. Hum, no. The basic promise of a que
by marcosdumay 1y ago
> The basic promise of a query optimizer is that it picks a good plan most of the time and does it quickly and efficiently.
Hum, no. The basic promise of a query optimizer is that it picks a good plan all of the time. Otherwise it's worse than useless and you would be better with a DB where you can pin the plan for every query.
But yes, the goal is on "good", not "optimal".
- RaftPeople 1y ago> The basic promise of a query optimizer is that it picks a good plan all of the time. The poster you responded to is correct, it's a combinatorial problem that can't be expected to pick a good plan all of the time within the normal data and time constraints.