The server process is not shared by any other client. PMON registers information about dedicated server processes with the listener. This enables the listener to start a dedicated server process when a client request arrives and forward the request to it. The following two figures show the basic difference between the shared server connection model and the traditional dedicated server connection model.
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This is a knowledge sharing forum, not a help, how-to, or homework forum, and such questions are likely to be removed. Dedicated server and shared server in oracle 19c self. To keep from typing a lot of text here's a link to an Oracle document that describes the two connection architectures, however there is a statement in it that I, and I believe most Oracle DBAs, would consider to be dated. In my 25 years of DBA work across a wide variety of applications, I've only configured shared server once, and that was in All dedicated server tasks allocate their PGA memory, which holds the working memory for client tasks, out of the system heap. Since the memory from the heap is attached directly to the dedicated task, no other tasks need to be able to access that memory.
Dedicated Server Processes
Dedicated vs. Oracle Database Tips by Donald Burleson. The Oracle multithreaded server MTS, later renamed "shared servers" was developed way-back in the days of Oracle7 when RAM was very expensive and RAM region sizes were severely limited by bit technology. Oracle shared servers are also inappropriate for ERP packages that spawn and hold database connections within the application server layer.
This chapter discusses the processes in an Oracle database system and the different configurations available for an Oracle system. All connected Oracle users must run two modules of code to access an Oracle database instance. Oracle database server code: Each user has some Oracle database code executing on his or her behalf, which interprets and processes the application's SQL statements.