Bryan Pendleton <[email protected]> writes: <good explanation of optimizer workings>
Doesn't this still leave the question why the test is unstable?: What could make the optimizer choice vary from test run to test run? I can think of the maximum time the optimizer would spend before it gives up looking for further plans, and that this could lead to different choice depending on machine performance, load etc. Does this test involve a large join? If not, what else could make the optimizer choice non-predictable? Dag
