RMAN-20035

I received this error today while configuring RMAN on one of the databases.

RMAN-20035: Invalid high RECID error

In this case Note 273446.1 from Oracle support was helpful.

It suggests to unregister the database using DBMS_RCVCAT.UNREGISTERDATABASE procedure.
and then register the database again.

This is what i did and the problem resolved as of now.
The following commands are helpful -->

select * from rc_database where dbid = DBID;

exec dbms_rcvcat.unregisterdatabase(DBKEY, DBID);

ORA-00600: internal error code, arguments: [4194],[],[]

I have very less experience in recovery of databases. However recently i have recovered big databases and in one of the databases i saw the error-
ORA-00600: internal error code, arguments: [4194],
Doing block recovery for file 5 block 18791
Block recovery from logseq 4237, block 76 to scn 6058257035817
This was continuously coming in alert log.
After searching for a while a solution that i came across was to drop undo table space and recreate it. And this is what i did and the error got resolved.
Hope this helps

Jumbo frames in Oracle RAC

Recently we implemented jumbo frames in our RAC environment, I have read a lot about jumbo frames and how they can be helpful in a cluster based environment but never actually experienced in a real time setup.
In one of the setups recently after migration , it was basically a hardware based migration, an upgrade to more advanced servers ,post migration database was slow and there were many Cluster related events. One of the main event being "gc cr request" and "gc cr congested" , these 2 events were in large count if we query gv$session_wait view.
There was no quick solution to this event and we tried to tune a few problematic sqls, which helped in reducing this event to some extent but most of the times the average CR block Receive Time was unusual then normal and so was average current block receive time.
Finally after a few days we had implemented JUMBO Frames in our rac environment, And just after implementing these, the average CR block Receive Time came down tremendously and also gc cr request and gc cr congested event were very very less.

So Jumbo frames are very much useful as i would say, although it is not recommended by support people.

adstrtal.sh: exiting with status 1

This is one of the messages i got while starting APPS tier of e-business suite.
I am new to this thing, so checked a few things. Logged onto the database , and tried to connect with apps user which was quite successful. Then i realized that may be listener is not up, and that was the culprit. So i started listener using command adalnctl.sh start PROD and once again started Apps tier which worked now!!

Alert tab of oracle Grid Control

We have grid control installed in one of our setups. This is quite useful as you can register all your databases here and monitor them from a centralized control. One of the good things i like about this is the alert tab. By clicking on the alert tab you can easily see all the errors coming in any of the databases whether they are ORA- errors or any other.
So another useful feature and observation from my side.

DBMS_SCHEDULER

This is some task i did for the first time in one of my recent projects.
so just an another attempt to share my learning.
To create a scheduled job the syntax is -

begin
sys.dbms_scheduler.create_job(job_name => 'test_job',
job_type => 'PLSQL_BLOCK',
job_action => 'BEGIN DBMS_STATS.gather_schema_stats(''ABC''); END;',
repeat_interval => 'FREQ=DAILY;BYHOUR=21;BYMINUTE=45;BYSECOND=0',
start_date => sysdate,
job_class => 'DEFAULT_JOB_CLASS',
comments => 'gather stats job',
auto_drop => TRUE,
enabled => TRUE);
END;