图中有八条箭线，因此需要设置八个信号量，按照从小到大的顺序分别是：P1→P2对应S1，P1→P3对应S2，P2→P3对应S3，P2→P3对应S3，P2→P4对应S4，P3→P4对应S5，P3→P5对应S6，P4→P6对应S7，P5→P6对应S8。每个进程开始的时候执行P操作（P1没有P操作，只有V操作），结束的时候执行V操作，如P2开始的时候执行P（S1）的操作，结束时执行V（S3）和V（S4）的操作，P3开始的时候执行P（S2）P（S3）的操作，结束时执行V（S5）和V（S6）的操作，其他同理。
Designing the data storage architecture is an important activity in system design. There are two main types of data storage formats： files and databases. Files are electronic of data that have been optimized to perform a particular transaction. There are several types of files that differ in the way they are used to support an application. （ ） store core information that is important to the business and , more specifically , to the application , such as order information or customer mailing information. （请作答此空） contain static values , such as a list of valid codes or the names of cities . Typically, the list is used for validation. A database is a collection of groupings of information that are related to each other in some way. There are many different types of databases that exist on the market today. （ ） is given to those databases which are based on older , sometimes outdated technology that is seldom used to develop new applications . （ ） are collections of records that are related to each other through pointers In relational database , （ ） can be used in ensuring that values linking the tables together through the primary and foreign keys are valid and correctly synchronized.
The service measurement metrics do not include （ ）。
The （ ） is the primary point of contact for users when there is a service disruption, for Service Requests, or even for some categories of Request for Change.
（ ） is pre-authorized by Change Management that has an accepted and established procedure to provide a specific change requirement.
The Service Design stage of the lifecycle starts with （ ） and ends with the development of a service solution designed to meet the documented needs of the business.
