ORA-12518 TNS:监听程序无法分发客户机连接 解决办法

查询的脚本:

select count(*) from v$process; --取得数据库目前的进程数。

select value from v$parameter where name = 'processes';     --取得进程数的上限。

-- 修改的脚本, 须用 system 用户或是 sys 用户进行修改

alter system set processes=1000 scope=spfile;

alter system set sessions=1100 scope=spfile;

我是用这一段来解决的

SQL> connect sys/test as sysdba

Was connected to an idle instance.

SQL> show parameters dispatchers;

ORA-01034: ORACLE not available

SQL> connect SYS/SYSADMIN as sysdba

Was connected to an idle instance.

SQL> select count(*) from v$session;

SQL> show parameter processes

SQL> alter system set processes=1000 scope=spfile;

SQL> alter system set sessions=1100 scope=spfile;

SQL> select  name, (busy/(busy + idle)) "dispatcher busy rate" from v$dispatcher ; 

　　重新登录就可以了

环境：windows XP +Oracle 10g R2

一、listener文件中的GLOBAL_DBNAME ,SID_NAME可能与实例名称不符，修改后，重启listener.

二、专有服务器模式下processes值设的过小。

　　可通过以下方法解决：

.cmd

.sqlplus

.connect sys/test as sysdba

.查看会话数、processes、sessions 

　　

SQL> select count(*) from v$session;

         COUNT(*)

        ----------

　　

SQL> show parameter processes

    NAME                                 TYPE        VALUE

    db_writer_processes                  integer     

    gcs_server_processes                 integer     

    job_queue_processes                  integer     

    log_archive_max_processes            integer     

    processes                            integer     

SQL> show parameter sessions

    NAME                                 TYPE        VALUE

    java_soft_sessionspace_limit         integer     0l

    icense_max_sessions                 integer     

    license_sessions_warning             integer     

    logmnr_max_persistent_sessions       integer     

    sessions                             integer     

    shared_server_sessions               integer 

　　.修改processes和sessions值:sessions=(1.1*process+)

  SQL> alter system set processes= scope=spfile;

 系统已更改。

SQL> alter system set sessions= scope=spfile;

   系统已更改。 

　　.重启数据库，使更改生效

　　（不过我没有重启）

三、共享模式下

.show parameters dispatchers;

show parameters dispatchers;

NAME TYPE VALUE

dispatchers string (protocol=tcp)(service=oracle10xdb)

max_dispatchers integer 

.确定是否有足够的dispatchers

SQL> select name, (busy/(busy + idle)) "dispatcher busy rate" from v$dispatcher ; 

NAME dispatcher busy rate

---- --------------------

D000 .

D001 .

D002 . 

如果超过50%，则需要考虑增加更多的dispatchers; 

.改变dispathchers:

SQL>alter system set dispatchers = '(protocol=tcp)(dispatchers=3)(service=oracle10xdb)';

system altered 

四、PGA内存设置太小

注：该方法没试过。

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按照如上我的解决方案：

cmd调出命令行窗口 

Microsoft Windows XP [Version 5.1.]
(C) Copyright - Microsoft Corp.

C:\Documents and Settings\Administrator>sqlplus /nolog

SQL*Plus: Release 10.2.0.1. - Production on 月 2月  :: 

Copyright (c) , , Oracle. All rights reserved.

SQL> connect sys/test as sysdba

Was connected to an idle instance.

SQL> show parameters dispatchers;

ORA-: ORACLE not available

SQL> connect SYS/SYSADMIN as sysdba

Was connected to an idle instance.

SQL> select count(*) from v$session;

SQL> show parameter processes

SQL> alter system set processes= scope=spfile;

SQL> alter system set sessions= scope=spfile;

SQL> select  name, (busy/(busy + idle)) "dispatcher busy rate" from v$dispatcher ; 

　　重新登录就可以了