ORA-12519, TNS:no appropriate service handler found [转]

错误现象：Oracle链接失败错误，报错日志如下：

Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found The Connection descriptor used by the client was:192.9.100.217:7001:wcm

问题分析：

可能是数据库上当前的连接数目已经超过了它能够处理的最大值.修改数据库允许的最大连接数即可解决

 

 

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知识扩展

 

select count(*) from v$process --当前的连接数
select value from v$parameter where name = 'processes' --数据库允许的最大连接数

修改最大连接数:
alter system set processes = 300 scope = spfile;

重启数据库:
shutdown immediate;
startup;

--查看当前有哪些用户正在使用数据
SELECT osuser, a.username,cpu_time/executions/1000000||'s', sql_fulltext,machine 
from v$session a, v$sqlarea b
where a.sql_address =b.address order by cpu_time/executions desc;