Oracle Database Design - Oracle 10g Database Administration Concepts and Implementation Made Simple - page 172

Figure 7-20: We will be running our oracle database server in
Dedicated Server Mode. Select the “Dedicated Server Mode” option.
You have been provided with two options whether you want to
run the Oracle Server in Dedicated Server Mode or Shared
Server Mode. In Dedicated Server Mode as explained before
there would be one server process per connected user whereas in
Shared Server Mode multiple users would be served by a single
server process. Select the Dedicated Server Mode if you want
high performance and if you have plenty of system resources
available otherwise go with Shared Server Mode.