SHARED_SERVERS

Parameter type	Integer
Default value	If you are using shared server architecture, then the value is 1. If you are not using shared server architecture, then the value is 0.
Parameter class	Dynamic: ALTER SYSTEM
Range of values	Operating system-dependent

SHARED_SERVERS specifies the number of server processes that you want to create when an instance is started up. If system load decreases, this minimum number of servers is maintained. Therefore, you should take care not to set SHARED_SERVERS too high at system startup.