@H_404_3@一、@H_404_3@listener@H_404_3@文件中的@H_404_3@GLOBAL_DBNAME,SID_NAME@H_404_3@可能与实例名称不符，修改后，重启@H_404_3@listener.
@H_404_3@二、专有服务器模式下@H_404_3@processes@H_404_3@值设的过小。
@H_404_3@1.cmd
@H_404_3@3.connect sys/testas sysdba
@H_404_3@4.@H_404_3@查看会话数、processes、sessions
@H_404_3@sql> selectcount(*) from v$session;
@H_404_3@ COUNT(*)
@H_404_3@
@H_404_3@ ----------
@H_404_3@ 45
@H_404_3@sql> showparameter processes
@H_404_3@ NAME TYPE VALUE
@H_404_3@ db_writer_processes integer 1
@H_404_3@ gcs_server_processes integer 0
@H_404_3@ job_queue_processes integer 10
@H_404_3@ log_archive_max_processes integer 2
@H_404_3@ processes integer 50
@H_404_3@sql> showparameter sessions
@H_404_3@ NAME TYPE VALUE
@H_404_3@ java_soft_sessionspace_limit integer 0l
@H_404_3@ icense_max_sessions integer 0
@H_404_3@ license_sessions_warning integer 0
@H_404_3@ logmnr_max_persistent_sessions integer 1
@H_404_3@ sessions integer 60
@H_404_3@ shared_server_sessions integer
@H_404_3@5.@H_404_3@修改@H_404_3@processes@H_404_3@和@H_404_3@sessions@H_404_3@值@H_404_3@:sessions=(1.1*process+5)
@H_404_3@ sql> alter system set processes=300scope=spfile;
@H_404_3@ sql> alter system set sessions=335scope=spfile;
@H_404_3@6.@H_404_3@重启数据库，使更改生效
@H_404_3@ （不过我没有重启）
@H_404_3@三、共享模式下
@H_404_3@1.show parameters dispatchers;
@H_404_3@show parametersdispatchers;
@H_404_3@NAME TYPE VALUE
@H_404_3@dispatchers string(protocol=tcp)(service=oracle10xdb)
@H_404_3@max_dispatchersinteger
@H_404_3@2.@H_404_3@确定是否有足够的@H_404_3@dispatchers
@H_404_3@sql> selectname,(busy/(busy + idle)) "dispatcher busy rate" from v$dispatcher ;
@H_404_3@NAME dispatcherbusy rate
@H_404_3@------------------------
@H_404_3@D000 .000121704
@H_404_3@D001 .000042597
@H_404_3@D002 .004935402
@H_404_3@如果超过50%，则需要考虑增加更多的dispatchers;
@H_404_3@3.@H_404_3@改变@H_404_3@dispathchers:
@H_404_3@sql>alter systemset dispatchers = '(protocol=tcp)(dispatchers=3)(service=oracle10xdb)';
@H_404_3@system altered
@H_404_3@四、@H_404_3@PGA@H_404_3@内存设置太小
@H_404_3@------------------------------------------------------------------------------------------------------------------------------------------------
