DB link的迁移（dblink中的密码未知）

seven >create public database link test connect to scott identified by tiger using 'ginna';

Database link created.

seven >select * from global_name@test;

GLOBAL_NAME
---------------------
GINNA

seven >select * from dba_db_links;

OWNER                          DB_LINK                        USERNAME                       HOST                           CREATED
------------------------------ ------------------------------ ------------------------------ ------------------------------ ---------
PUBLIC                         TEST                           SCOTT                          ginna                          06-MAR-15

seven >create table trans1 as select * from sys.link$;

Table created.

seven >select count(*) from trans1;

  COUNT(*)
----------
         1

seven >conn seven/oracle
Connected.
seven >create table trans2 as select * from sys.link$;   -----当然不能直接CTAS基表的。
create table trans2 as select * from sys.link$
                                         *
ERROR at line 1:
ORA-01031: insufficient privileges

seven >create table trans2 as select * from sys.trans1;

Table created.
seven >select count(*) from trans2;

  COUNT(*)
----------
         1
seven >

ginna >show user
USER is "SYS"
ginna >select * from dba_db_links;

no rows selected

ginna >create public database link test2 connect to seven identified by oracle using 'seven';

Database link created.

ginna >select * from global_name@test2;

GLOBAL_NAME
----------------------
SEVEN

ginna >set line 200
ginna >col db_link for a30
ginna >col host for a30
ginna >select * from dba_db_links;

OWNER                          DB_LINK                        USERNAME                       HOST                           CREATED
------------------------------ ------------------------------ ------------------------------ ------------------------------ ---------
PUBLIC                         TEST2                          SEVEN                          seven                          06-MAR-15

ginna >create table trans3 as select * from trans2@test2;

Table created.

ginna >select count(*) from trans3;

  COUNT(*)
----------
         1

ginna >truncate table sys.link$;

Table truncated.

ginna >insert into sys.link$ select * from trans3;

1 row created.

ginna >commit;

Commit complete.

ginna >select * from dba_db_links;

OWNER                          DB_LINK                        USERNAME                       HOST                           CREATED
------------------------------ ------------------------------ ------------------------------ ------------------------------ ---------
PUBLIC                         TEST                           SCOTT                          ginna                          06-MAR-15

ginna >select * from global_name@test;

GLOBAL_NAME
------------------
GINNA

ginna >create public database link test2 connect to seven identified by oracle using 'seven';
create public database link test2 connect to seven identified by oracle using 'seven'
                            *
ERROR at line 1:
ORA-02011: duplicate database link name

ginna >alter system flush shared_pool;

System altered.

ginna >create public database link test2 connect to seven identified by oracle using 'seven';

Database link created.

ginna >select * from dba_db_links;

OWNER                          DB_LINK                        USERNAME                       HOST                           CREATED
------------------------------ ------------------------------ ------------------------------ ------------------------------ ---------
PUBLIC                         TEST                           SCOTT                          ginna                          06-MAR-15
PUBLIC                         TEST2                          SEVEN                          seven                          06-MAR-15

ginna >

SQL> drop public database link test2;
drop public database link test2
                          *
ERROR at line 1:
ORA-00603: ORACLE server session terminated by fatal error
ORA-00600: internal error code, arguments: [16500], [kqdDBLinkUpdate], [3], [0], [TEST2], [], [], [], [], [], [], []
Process ID: 11165
Session ID: 152 Serial number: 359


SQL> 
SQL> create public database link test2 connect to seven identified by oracle using 'seven';
ERROR:
ORA-03114: not connected to ORACLE


SQL> conn / as sysdba
Connected.
SQL> create public database link test2 connect to seven identified by oracle using 'seven';

Database link created.

SQL> drop public database link test2;

Database link dropped.

SQL>