Oracle数据库tnsnames.ora文件的作用和配置

#该文件用于配置数据库连接地址
#数据库访问地址别名（随便起）
ORCL=
(DESCRIPTION =
    (ADDRESS_LIST =
#通讯协议，主机，端口
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.10)(PORT = 1521))
    )
    (CONNECT_DATA =
#数据库实例名称
      (SERVICE_NAME = orcl)
    )
)

#配置多个数据库地址
#ORCL2=
#(DESCRIPTION =
#    (ADDRESS_LIST =
#      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.11)(PORT = 1521))
#    )
#    (CONNECT_DATA =
#      (SERVICE_NAME = orcl)
#    )
#)

view plain
LSNRCTL> help   
The following operations are available   
An asterisk (*) denotes a modifier or extended command:   
start stop status   
services version reload   
save_config trace change_password   
quit exit set*   
show*   
LSNRCTL> status   

C:/>tnsping orcl   
TNS Ping Utility for 32-bit Windows: Version 10.1.0.2.0 - Production on 16-8月 -   
2005 09:36:08   
Copyright (c) 1997, 2003, Oracle. All rights reserved.   
Used parameter files:   
E:/oracle/product/10.1.0/Db_2/network/admin/sqlnet.ora   
Used TNSNAMES adapter to resolve the alias   
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)   
(HOST = 127.0.0.1)(PORT = 1521))) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_   
NAME = orcl)))   
OK (20 msec)   

SQL> select open_mode from v$database; 查看数据库是打开还是mount状态。   
　　OPEN_MODE   
　　----------  
　　READ WRITE