能使在同一轴心线上的两根轴，在机器运转过程中接合或分离的叫（） 联轴器。 制动器。 离合器。 控制器。
有效竞争理论是由（）提出 克拉克。 爱德华·H.张伯伦。 乔安·罗宾逊夫人。 霍夫曼。
Identify three scenarios in which you would recommend the use of SQL Performance Analyzer to analyzeimpact on the performance of SQL statements.（） Change in the Oracle Database version。 Change in your network infrastructure。 Change in the hardware configuration of the database server。 Migration of database storage from non-ASM to ASM storage。 Database and operating system upgrade。
所谓“首因心理”，就是人在相互认识的活动中，最初获得的关于对象的信息，在评价对象时起着重要的作用。（）
Which two statements are true about Oracle Real Applications Insight ？（） it provides enhanced visibility across the entire application infrastructure 。 it provides a set of management tools that enable automation of configuraion。 it significantly increases the performance of Web-based applications with no code change。 it dramatically reduces costs associated with diagnostics， configuration， and deployment on production servers&e。
Users complain about the slow response time of queries. While investigating the cause you find that the Oracle Instance is not configured to cache all of the data blocks to satisfy the users’queries. Which component of the Oracle Instance would you change to improve performance？（）
