Workshop: Best Practices for Oracle DB on Exadata: RUN, It’s Free!

Hey, you in Porto Alegre/Brazil!

Don’t miss this opportunity to have an official Oracle Workshop about Exadata Best Practices for Oracle Database!

This is being being promoted by GUORS in partnership with Oracle Brasil.

Draft - Convite (1)

When? June 26th from 2PM to 6PM BRT.
Where?  TecnoPUC-RS, room 206 – building 99A
Instructor: Valter Rodrigues da Oracle Brasil.

LIMITED POSITIONS: 30!


Requirements
:

1. Like GUORS Page on Facebook AND LinkedIn
2. Like Oracle University on LinkedIn
3. Like GUOB on LinkedIn
4. Bring your notebook.
5. Basic knowledge on RAC

Subscribe ASAP!

Oracle: Explicitly Lock a Table

Hello all,
So I client had a process that kept need big chunks locks on a table. Problem is that due application use this lock occasionally failed (lock timeout) and the whole process fail. So how to guarantee this?

Using explicit locks for the table before starting the procedure, with command below:

LOCK TABLE GREPORA.GREP_TABLE IN SHARE MODE;

This lock is released as soon as the session commit or rollback transaction in the current session. Killing session means an implicit rollback, as usual.

The SHARE permits concurrent queries but prohibits updates to the locked table.

Nice right?
Hope it helps you too!

ORA-31600: invalid input value DATABASE LINK for parameter OBJECT_TYPE in function GET_DDL When Dropping DBLink

So while back there was an error while trying to drop a public database link

SQL> drop public database link "BOB.DATABASE_LINK_1";
drop public database link "BOB.DATABASE_LINK_1"
*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-31600: invalid input value DATABASE LINK for parameter OBJECT_TYPE in
function GET_DDL
ORA-06512: at "SYS.DBMS_METADATA", line 5805
ORA-06512: at "SYS.DBMS_METADATA", line 8344
ORA-06512: at line 14

And the even strange part is that executing DBMS_METADATE.get_ddl worked against the database link

SQL> SELECT dbms_metadata.get_ddl('DB_LINK','BOB.DATABASE_LINK_1','SYS') FROM dual;

CREATE DATABASE LINK "BOB.DATABASE_LINK_1"
CONNECT TO "NYU" IDENTIFIED BY VALUES '*******'
USING 'ORCL';

The solution relied on MOS note Cannot drop a database link after changing the global_name ORA-02024 (Doc ID 382994.1) all though the symptoms in the note were not a match to the problem above the solution did the trick.
Which is to backup the table sys.link$ as CTAS and delete the row corresponding to the database link which you need to drop.

Take a complete consistent backup of the database or use CTAS can be used to backup sys.link$:

$sqlplus /nolog
connect / as sysdba

SQL> create table backup_link$ as select * from sys.link$:

Delete the DBLINK as follows:

$sqlplus /nolog
connect / as sysdba

SQL> delete sys.link$ where name='db_link_name>';

SQL>commit;

Verify if the operation was correctly proceeded:

select db_link, username, host from user_db_links;

Hope it helps!

OEM13c: Regions that display real-time data will not be displayed. Exception while loading RAC Database Home Page: null

Hi all,
So I was having this issue from a Database Home page on OEM 13c:

image_OEMBug.png

Actually, OMS log was presenting several null pointer exceptions… So, whats is the deal?

Everything seemed to match to MOS Bug 22957131 – OEM13C: Exception while loading RAC Database Home Page: null.

The solution?
– Patch 25197714 for the EM 13.2 OMS
– Patch 25155095 for the EM 13.1 OMS

Also, those fixes are included on following Boudle Patches:
– 13.2.1.0.161231
– 13.1.1.0.161220

Applied the patch and solved my case. Hope it helps you!

More Reference:
– EM 13C: Target Database Home Page Displays Message in Enterprise Manager 13c Cloud Control: Regions that display real-time data will not be displayed. Exception while loading RAC Database Home Page: null (Doc ID 2210123.1)
– Note 2219797.1 Enterprise Manager 13.2 Master Bundle Patch List
– Note 2124038.1 Enterprise Manager 13.1 Master Bundle Patch List for the Management Agent and Plug-ins