Wednesday, July 13, 2011

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);

Monday, July 11, 2011

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

Tuesday, April 12, 2011

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.