SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = zlm_SN)
(ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
(SID_NAME = zlm)
)
)
经过上面的tnsnames.ora和linstener.ora的配置，当我们查看监听状态的时候，就会发现不同：
$lsnrctl status
......
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "zlm_SN" has 1 instance(s).## 表示对应的SERVICE_NAME为zlm_SN
Instance "zlm", status UNKNOWN, has 1 handler(s) for this service... ##表示对应的INSTANCE_NAME为zlm，也即SID和ORACLE_SID
The command completed successfully
而通常情况下，我们会设置SERVICE_NAME和INSTANCE_NAME一致。这里还要注意的是，SERVICE_NAME虽然可以脱离INSTANCE_NAME搞别名，但是必须对应listener.ora里配置的GLOBAL_DBNAME，否则就算配好了静态监听，也是注册不了服务的
注意，数据库数据文件存放的路径，是根据DB_NAME来确定的，而对于单实例数据库而言，默认与SID和INSTANCE_NAME是一致的，当然，也可以不一致(有DB_DOMAIN的情况下)，DBCA的时候可以选择，通常这3个参数在DBCA的时候确认下来后，就基本不再去修改了，那么数据文件路径也就确定下来了，如我的环境中：
数据文件就放在/u01/app/oracle/oradata/zlm下面
而跟踪日志就放在/u01/app/oracle/admin/zlm/bdump下面
过了片刻以后，再查看监听状态，发现自动还是会去动态注册一个和INSTANCE_NAME(SID)一致的SERVICE_NAME
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.1.91)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "zlm" has 1 instance(s).
Instance "zlm", status READY, has 1 handler(s) for this service...
Service "zlmXDB" has 1 instance(s).
Instance "zlm", status READY, has 1 handler(s) for this service...
Service "zlm_SN" has 1 instance(s).
Instance "zlm", status UNKNOWN, has 1 handler(s) for this service...
Service "zlm_XPT" has 1 instance(s).
Instance "zlm", status READY, has 1 handler(s) for this service...
The command completed successfully
这样的话，我个人判断，如果不配置静态监听的话，pmon进程始终会去监听那里注册一个名字和INSTANCE_NAME(SID)一致的SERVICE_NAME，即便是已经在tnsnames.ora中修改了SERVICE_NAME=zlm_SN，而只有通过静态监听强制注册一个与INSTANCE_NAME(SID)不一致的SERVICE_NAME，才会被监听到