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.
Hope it helps you too!
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
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 '*******'
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$:
connect / as sysdba
SQL> create table backup_link$ as select * from sys.link$:
Delete the DBLINK as follows:
connect / as sysdba
SQL> delete sys.link$ where name='db_link_name>';
Verify if the operation was correctly proceeded:
select db_link, username, host from user_db_links;
Hope it helps!
So I was having this issue from a Database Home page on OEM 13c:
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.
– 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:
Applied the patch and solved my case. Hope it helps you!
– 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