问题1：ORA-12154: TNS: 无法解析指定的连接标识符

在一台服务器上部署了Oracle客户端，使用IP/SID的方式访问，老是报ORA-12154错误，而使用tnsnames访问却没有问题，对比了我本机的配置并查阅了一下资料，Easy Connect Naming Method这个东西是Oracle 10g推出的，需要在sqlnet.ora文件中添加EZCONNECT，如下：

# sqlnet.ora Network Configuration File: C:\app\Administrator\product\11.2.0\client_1\network\admin\sqlnet.ora
# Generated by Oracle configuration tools.

# This file is actually generated by netca. But if customers choose to 
# install "Software Only", this file wont exist and without the native 
# authentication, they will not be able to connect to the database on NT.

sqlNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH = (TNSNAMES,EZCONNECT)

问题2：ORA-12514: TNS: 监听程序当前无法识别连接描述符中请求的服务

1、通过重启服务的方式启动数据库和监听服务，再次连接仍无法连接服务器。

2、考虑检查监听listener.ora文件的配置

监听@R_301_382@listener.ora中可以不必指定监听的服务名（安装Oracle10g后也是没有指定的）。正常情况下一般只要数据库启动，客户端连接数据库也没有什么问题，但是有时重复启动关闭也会出现ORA-12514错误。

既然listener.ora中没有指定监听，我们可以在listener.ora文件中指定监听的实例名，这样该问题应该可以连接。

# listener.ora Network Configuration File: D:\app\Administrator\product\11.2.0\dbhome_1\NETWORK\ADMIN\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:\app\Administrator\product\11.2.0\dbhome_1)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:C:\app\Administrator\product\11.2.0\dbhome_1\bin\oraclr11.dll")
    )
    (SID_DESC =

 (GLOBAL_DBNAME = ora11r2)  (SID_NAME = ora11r2)

 )  
)

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.101)(PORT = 1521))
    )
  )

ADR_BASE_LISTENER = C:\app\Administrator

select t1.*,t2.CurrentValue
from (select t.NAME,t.VALUE 
      from v$parameter t 
      where t.name in ('processes',sessions')
     ) t1
     join (
       select ' as name,255); line-height:1.5!important">count(1) as CurrentValue from v$process
       union all
       from v$session
     ) t2 on t1.name = t2.name

sql> alter system set processes=1000 scope=spfile;
sqlset sessions1200 scope=spfile;