ORA-27100 shared memory realm already existsCause: An attempt was made to start duplicate instances, or tried to restart an instance
that had not been properly shut down.Action: Use a different instance name, or cleanup the failed instance's SGA.
that had not been properly shut down.Action: Use a different instance name, or cleanup the failed instance's SGA.
connect / as sysdba
shutdown abort
startup
此外,检查ORACLE_HOME环境变量。如何检查参考如下的命令: % echo $ORACLE_SID
% ps -ef |grep smon ->如果是Windows,一般都是因为系统中有多个实例造成的。 可以在命令行下 C:\>set ORACLE_SID=DEMO 把这里的DEMO换为你相应的实例名。 如果还不行的话,检查注册表中的ORACLE_HOME。
此外,在Windows环境下有的时候连接不上远程的数据库,会报告如此的错误。 解决办法是把sqlnet.ora文件中的
SQLNET.AUTHENTICATION_SERVICES = (NTS) NTS换为NONE