登录到远程上的结果：
net97>show parameters global_name
NAME TYPE VALUE
global_names boolean FALSE
net97>
net97>drop database link jinhua;
数据库链接已丢弃。
net97>create database link jinhua
2 connect to username identified by password
3 using 'jinhua';
数据库链接已创建。
net97>select * from so@jinhua;
select * from so@jinhua
*
ERROR 位于第 1 行:
ORA-12154: TNS:不能分解服务名称.
net97>conn username/password@jinhua;
已连接。
net97>
///////////////////////////////////////////////////
登录到本地的NTserver 上面的ORacle816数据库：
本地的tnsnames.ora文件里边有jinhua这个连接串的描述。
//////////////////////////////////////////////////////////////
GLOBAL_NAME=TRUE的时候的情况：
SQL> show parameters global
NAME TYPE VALUE
------------------------------------ ------- ------------------------------
global_names boolean TRUE
SQL>
SVRMGR> create database link jinhua
2> connect to spgroup identified by spgroup
3> using 'jinhua';
语句已处理。
SVRMGR> select count(*) from spgroup.so@jinhua;
select count(*) from spgroup.so@jinhua
*
ORA-02085: ?????JINHUA.world?ORCL.WORLD???
SVRMGR> drop database link jinhua;
语句已处理。
SVRMGR> create database link jinhua.world
2> connect to username identified by password
3> using 'jinhua';
语句已处理。
SVRMGR> select count(*) from username.so@jinhua.world;
select count(*) from username.so@jinhua.world
*
ORA-02085: ?????JINHUA.WORLD?ORCL.WORLD???
SVRMGR> drop database link jinhua.world;
语句已处理。
SQL> conn chaos/chaos
已连接。
SQL> create database link orcl.world
2 connect to spgroup identified by spgroup
3 using 'jinhua';
数据库链接已创建。
SQL> select count(*) from spgroup.so@orcl.world;
COUNT(*)
----------
6800
SQL>
///////////////////////////////////////////////////////////////////
GLOBAL_NAME=FALSE时候的情况：
SQL> shutdown immediate;
数据库已经关闭。
已经卸载数据库。
ORACLE 例程已经关闭。
SQL> startup
ORACLE 例程已经启动。
Total System Global Area 16930844 bytes
Fixed Size 75804 bytes
Variable Size 8388608 bytes
Database Buffers 8388608 bytes
Redo Buffers 77824 bytes
数据库装载完毕。
数据库已经打开。
SQL> show parameter global_name
NAME TYPE VALUE
global_names boolean FALSE
SQL>
SQL> create database link jinhua
2 connect to spgroup identified by spgroup
3 using 'jinhua';
数据库链接已创建。
SQL> select count(*) from so@jinhua;
COUNT(*)
----------
6800
//////////////////////////////////////////////////////////////////
数据库连接串的密码存放在user_db_links里边的password字段里边。
To facilitate application requests in a distributed database system,
uses
database links. A database link defines a one-way communication path from an
database to another database.
Database links are essentially transparent to the users of an Oracle
distributed database system, because the name of a database link is the same as the global name
of the database to which the link points. For example, the following SQL statement creates a database link in the local database that describes a path to the remote
SALES.US.AMERICAS.ACME_AUTO.COM database.
CREATE DATABASE LINK sales.us.americas.acme_auto.com ... ;
After creating a database link, applications connected to the local database can access data in the remote SALES.US.AMERICAS.ACME_AUTO.COM database. The next section explains how applications can reference remote schema objects in a distributed database and includes examples of how SQL statements use database links.
Additional Information: Oracle supports several different types of database links. For more information, see Oracle8i Distributed
Database Systems.
【责编:admin】
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