The OPTIMIZER_USE_PLAN_BASELINES parameter is set to TRUE. The optimizer generates a plan for a SQL statement but does not find a matching plan in the SQL plan baseline. Which two operations are performed by the optimizer in this scenario?()
A. The optimizer adds the new plan to the plan history.
B. The optimizer selects the new plan for the execution of the SQL statement.
C. The optimizer adds the new plan to the SQL plan baseline as an accepted plan.
D. The optimizer adds the new plan to the SQL plan baseline but not in the ENABLED state.
E. The optimizer costs each of the accepted plans in the SQL plan baseline and picks the one with the lowest cost.
查看答案
根据腐蚀机理,可以将金属分为()。
A. 化学腐蚀和电化学腐蚀
B. 全腐蚀和局部腐蚀
C. 磨损腐蚀和小孔腐蚀
D. 晶间腐蚀和电偶腐蚀