因子分析的作用是（）。 寻求数据的基本结构。 划分类型。 数据化简。 解释变量之间的因果关系。 描述变量之间的差异。
You have two database servers SEMP and SACCT. The database in the SEMP server maintains the employeeinformation and the database in the SACCT server maintains the accounts payable information. The employeessubmit the expense reports to the accounts payable department. A user of the accounts payable databasewants to extract the employee information from the database in the SEMP server for cross-verification. Whichschema object enables the user to access the information from the remote database（） Cluster。 Database link。 Mapping table。 Materialized view。
在我国，由货物运输部门代理货物运输保险业务，由航空人身意外伤害保险等的兼业代理形式，属于（） 银行代理。 机关代理。 行业代理。 社区代理。
原发性血小板减少性紫癜，下列哪种血小板抗体特异性较强（） PAIgA。 PAIgG。 PAIgM。 PAC3。
From the V$SESSION_LONGOPS view， you find that some of the database users have longrunning queries and are consuming a lot of CPU time. This causes problems for you when you try to log on as the system user and perform small maintenance tasks. You would like to ensure that users SYS and SYSTEM get priority over all other users. Which method would you use to achieve this objective？（） create a plan directive in the SYS_GROUP。 create the pending area for the consumer group。 activate the provided SYSTEM_PLAN in Resource Manager。 set the TIMED_STATISTICS parameter to TRUE in the parameter file。 set the execution time limit for all users， except SYS and SYSTEM， in their profile。
A team of programmers is reviewing a proposed API for a new utility class. After some discussion,they realize that they can reduce the number of methods in the API without losing any functionality.If they implement the new design, which two OO principles will they be promoting?（）
