Oracle中的shared server

与shared server相关的参数
SHARED_SERVERS: Specifies the initial number of shared servers to start and the minimum number of shared servers to keep. This is the only required parameter for using shared servers.

MAX_SHARED_SERVERS: Specifies the maximum number of shared servers that can run simultaneously.

SHARED_SERVER_SESSIONS: Specifies the total number of shared server user sessions that can run simultaneously. Setting this parameter enables you to reserve user sessions for dedicated servers.

DISPATCHERS: Configures dispatcher processes in the shared server architecture.

MAX_DISPATCHERS: Specifies the maximum number of dispatcher processes that can run simultaneously. This parameter can be ignored for now. It will only be useful in a future release when the number of dispatchers is auto-tuned according to the number of concurrent connections.

CIRCUITS: Specifies the total number of virtual circuits that are available for inbound and outbound network sessions

使用shared server
alter system set shared_servers=5;

不使用shared server
alter system set shared_server=0;
ALTER SYSTEM SET DISPATCHERS = '';

当使用shared servers时 仍可以使用Dedicated mode, 只需要在tnsnames.ora中添加servers=dedicated即可.当为shared时说明使用shared server.
如果还不能使用 则要检查参数dispatchers.
典型的是 DISPATCHERS="(PROTOCOL=TCP)(DISPATCHERS=2)"
三个相关的view  V$QUEUE  V$DISPATCHER   V$DISPATCHER_RATE

查看dispatcher
SELECT NAME, NETWORK FROM V$DISPATCHER;
shutdown dispatcher
ALTER SYSTEM SHUTDOWN IMMEDIATE 'D002';