研究幼儿园管理的常用方法，主要有以下几种（） 调查法。 文献法。 实验法。 案例法。
Manually， you set the consumer group of all of the newly created users to MYDB_GRP. You want the users to be able to change their consumer groups as per the application requirement. What was the first step that was needed in the process to achieve this objective？（） The user must have been granted the DBA role.。 The user must have been granted the switch privilege as a part of a role.。 The user must have been granted the Resource Manager administrator privilege.。 The user must have been granted the switch privilege by using the DBMS_RESOURCE_MANAGER_PRIVS package.。
病毒的化学组成及各组成，它们各自的作用是什么？
A customer is experiencing a performance bottleneck. The server is performing sequential I/O requests with large block sizes of 64KB. Improving which of the following storage subsystem characteristics has the biggest impact on this bottleneck？（） Seek Time。 Drive RPM。 Data Transfer Rate。 Rotational Latency。
步进电动机的转速（）。 与电源脉冲幅值成正比。 与电源脉冲数成正比。 与电源脉冲宽度成正比。 与电源脉冲频率成正比。
水灾、火灾是造成计算机网络安全隐患的（）
