Server Processes (112)

Oracle creates server processes to handle the requests of user processes connected to
the instance. In some situations when the application and Oracle operate on the same
computer, it is possible to combine the user process and corresponding server process
into a single process to reduce system overhead. However, when the application and
Oracle operate on different computers, a user process always communicates with
Oracle through a separate server process.
Server processes (or the server portion of combined user/server processes) created on
behalf of each user’s application can perform one or more of the following:
■ Parse and run SQL statements issued through the application
■ Read necessary data blocks from datafiles on disk into the shared database buffers
of the SGA, if the blocks are not already present in the SGA
■ Return results in such a way that the application can process the information

伺服器程式(使用者應用程式端)
1. 解析執行SQL語句
2. 將資料塊從SGA讀取到shared database buffers
3. 返回應用程式能處理的資訊

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