当线圈的匝数，电压不变时，电源频率增高，铁芯中磁通会（）。 减少。 增加。 不变。
You notice a performance change in your production Oracle 12c database. You want to know which change caused this performance difference. Which method or feature should you use?（） Compare Period ADDM report。 AWR Compare Period report。 Active Session History (ASH) report。 Taking a new snapshot and comparing it with a preserved snapshot。
An index called ORD_CUSTNAME_IX has been created on the CUSTNAME column in the ORDERS table using the following command： SQL>CREATE INDEX ord_custname_ix ON orders（custname）； The ORDERS table is frequently queried using the CUSTNAME column in the WHERE clause. You want to check the impact on the performance of the queries if the index is not available. You do not want the index to be dropped or rebuilt to perform this test. Which is the most efficient method of performing this task？（） disabling the index。 making the index invisible。 making the index unusable。 using the MONITORING USAGE clause for the index。
简述Edit组件这几个属性的用途：Font、Hint、Name、ReadOnly、Text
我国刑罚中，主刑包括（）。 罚金。 罚款。 拘役。 管制。
You want to use the SQL Tuning Advisor to generate recommendations for badly written SQL statements in your development environment. Which three sources can you select for the advisor to analyze？（）
