Comments on: Recreating Database Link

By: Amit

Amit — Thu, 12 Mar 2009 18:25:21 +0000

Actually password field is empty in link$ in 10g. I was trying to use password field from DBA_USERS view. While checking further I found that we can also get the encrypted password from field "passwordx" from SYS.LINK$


SQL> SELECT NAME,HOST,USERID,PASSWORDX FROM SYS.LINK$;

NAME                                     HOST       USERID     PASSWORDX
---------------------------------------- ---------- ---------- ----------------------------------------
TO_AMIT.REGRESS.RDBMS.DEV.US.ORACLE.COM  test10     AMIT       0524F74E2CD3E3B4E10F290B25DBE943B6
TO_AMIT.REGRESS.RDBMS.DEV.US.ORACLE.COM  test10     AMIT       0524F74E2CD3E3B4E10F290B25DBE943B6
TO_AMIT.REGRESS.RDBMS.DEV.US.ORACLE.COM  test10     AMIT       0524F74E2CD3E3B4E10F290B25DBE943B6

This is same as the password which we get from dbms_metadata.get_ddl function. Meanwhile in case of 8i you can use below query to extract script for creating database link for particular user select 'create database link '||a.db_link||' connect to '||a.username||' identified by '||b.password||' using '''||a.HOST||''';' from dba_db_links a, sys.link$ b, dba_users c where a.owner=c.username and b.owner#=c.user_id and a.db_link=b.name and a.host=b.host and a.owner='&user' ;

By: coskan

coskan — Tue, 10 Mar 2009 21:08:40 +0000

HI Amit,

Thank you very much for the info and Gary thank you very much for the update.

One question ;

you said;

In case of 10g passwords are stored in encrypted format in SYS.LINK$.

I checked ;

The password column on both 10.2.0.4/10.2.0.3 is empty. Do you use a lower version ?

By: Amit

Amit — Fri, 30 Jan 2009 17:21:19 +0000

Yeah.. I didn’t realize that DBMS_METADATA.GET_DDL can also be used. I tried the same and it worked

SQL> select dbms_metadata.get_ddl(‘DB_LINK’,'TO_AMIT.REGRESS.RDBMS.DEV.US.ORACLE.COM’,'TEST’) from dual;

Thanks Gary !!

By: Gary

Gary — Thu, 29 Jan 2009 00:17:27 +0000

I read the metalink note.
I think it boils down to the string for IDENTIFIED BY VALUES isn’t the one in DBA_USERS PASSWORD column.
However DBMS_METADATA.GET_DDL does get the appropriate value.
Try the following :

create database link hr connect to hr identified by hr using ‘XE’;
select dbms_metadata.get_ddl(‘DB_LINK’,'HR’) from dual;
CREATE DATABASE LINK “HR”
CONNECT TO “HR” IDENTIFIED BY VALUES ’05C5ECC5A6E55600878A1D2614915CA506′
USING ‘XE’
select * from dual@hr;