Could anyone help me to understand the below points.
- How to select this time plan basing on what cost information which optimizer examined in advanve of the execution,
- and whether the selected plan is determined as much lower cost by optimizer,
- or whether there were any other plan which will cause the error and not so different as the cost value.
Thanks in Advance.
Not sure I understand all of your question, especially the part about an error occurring.
- the optimizer selects the plan not the user. The choice is based primarily on cost of alternate plans (with a few heuristics for special cases).
- There is not visibility into alternate plans and costs that the optimizer considered.