Dedicated Server Configuration
Figure 9–4 illustrates Oracle running on two computers using the dedicated server
architecture. In this configuration, a user process runs the database application on one
computer, and a server process runs the associated Oracle database server on another
computer.
独占服务配置
图9-4列出了ORACLE运行在两台电脑上使用独占服务架构。在这个配置中，一个数据库应用
用户进程运行在一台电脑上，并且与ORACLE服务相关的服务进程运行在另一台电脑上。
Figure 9–4 Oracle Using Dedicated Server Processes
shadow process), because this server process acts only on behalf of the associated user
process.
用户和服务进程是分开的，唯一的进程。服务进程创建对应每个用户进程叫做是一个独占
服务进程（或者影子进程）,因为这个服务进程只服务于唯一一个相关的用户进程。
This configuration maintains a one-to-one ratio between the number of user processes
and server processes. Even when the user is not actively making a database request,
the dedicated server process remains (though it is inactive and can be paged out on
some operating systems).
这个配置维持在1：1的关系在用户与服务进程的数量上。尽管当用户是未活动的发出数据
库的请求，专用服务进程保留（如果它是未活动的在一些操作系统会被调出）
Figure 9–4 shows user and server processes running on separate computers connected
across a network. However, the dedicated server architecture is also used if the same
computer runs both the client application and the Oracle database server code but the
host operating system could not maintain the separation of the two programs if they
were run in a single process. UNIX is a common example of such an operating system.
In the dedicated server configuration, the user and server processes communicate
using different mechanisms:
图9-4显示了用户和服务进程运行在各自的电脑，它们连接通过网络。但是，在专用服务器
架构也是可用在当同一台电脑运行客户端应用和ORACLE数据库服务代码，但是主机上
的操作系统不能各自维护两个进程单独的如果它们运行在一个单独的进程上。UNIX是此类
操作系统的一个常见例子。在专用服务配置里，用户和服务进程通信使用不同的机制。
■ If the system is configured so that the user process and the dedicated server
process run on the same computer, the program interface uses the host operating
system’s interprocess communication mechanism to perform its job.
如果服务已经配置成用户进程和专用服务进程在同一台电脑上，编程接口使用主机操作系统
的内部进程通信机制去执行它们的任务。
■ If the user process and the dedicated server process run on different computers,
the program interface provides the communication mechanisms (such as the
network software and Oracle Net Services) between the programs.
如果用户进程和专用服务进程运行在不同的电脑上，那么程序接口提供了通信的机制（
比如网络软件和ONS）在不同的进程之间。
■ Dedicated server architecture can sometimes result in inefficiency. Consider an
order entry system with dedicated server processes. A customer places an order as
a clerk enters the order into the database. For most of the transaction, the clerk is
talking to the customer while the server process dedicated to the clerk’s user
process remains idle. The server process is not needed during most of the
transaction, and the system is slower for other clerks entering orders. For
applications such as this, the shared server architecture may be preferable.
专用服务架构有时候是有效的。假设一个订单输入系统使用专用的服务进程，一个
用户发送一个订单给业务员要求在数据库中输入订单。
对于大多数事务，这个业务与用户交流而这个过程中业务员的进程保持空闲。这个
服务进程在事务的大多时候是不需要的，并且系统对于其它业务输入订单
也是比较慢的，对于这样的应用，共享服务架构可能会更适宜。
