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This article mainly introduces Oracle how to create a new undo tablespace, the article is very detailed, has a certain reference value, interested friends must read it!

When dealing with an ORA-600 [4194] case, refer to the MOS document: Step by step to resolve ORA-600 4194 4193 4197 on database crash (document ID 1428786.1)

1. Interpretation of ORA 600 [4194]

two。 Best practices for creating new undo tablespaces (including segment checking)

1. Interpretation of ORA 600 [4194]:

The following error is occurring in the alert.log right before the database crashes.

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

This error indicates that a mismatch has been detected between redo records and rollback (undo) records.

ARGUMENTS:

Arg [a]-Maximum Undo record number in Undo block

Arg [b]-Undo record number from Redo block

Since we are adding a new undo record to our undo block, we would expect that the new record number is equal to the maximum record number in the undo block plus one. Before Oracle can add a new undo record to the undo block it validates that this is correct. If this validation fails, then an ORA-600 [4194] will be triggered.

As you can see, this error is due to a mismatch between the records of redo and undo. It is common in scenarios such as abnormal power outages.

two。 Best practices for creating new undo tablespaces (including segment checking)

Best practice to create a new undo tablespace.his method includes segment check. Create pfile from spfile to editSQL > Create pfile='/tmp/initsid.ora' from spfile; Shutdown the instance set the following parameters in the pfile / tmp/initsid.ora undo_management = manual event = '10513 trace name context forever, level 2' SQL > > startup restrict pfile='/tmp/initsid.ora' SQL > select tablespace_name, status, segment_name from dba_rollback_segs where status! = 'OFFLINE' This is critical-we are looking for all undo segments to be offline-System will always be online.If any are 'PARTLY AVAILABLE' or' NEEDS RECOVERY'-Please open an issue with Oracle Support or update the current SR. There are many options from this moment and Oracle Support Analyst can offer different solutions for the bad undo segments.If all offline then continue to the next step Create new undo tablespace-exampleSQL > create undo tablespace datafile size 2000M; Drop old undo tablespaceSQL > drop tablespace including contents and datafiles; SQL > shutdown immediate;SQL > startup nomount;-- > Using your Original spfile. Modify the spfile with the new undo tablespace nameSQL > Alter system set undo_tablespace =''scope=spfile;. SQL > shutdown immediate;. SQL > startup;-- > Using spfile above is all the content of the article "how Oracle creates a new undo tablespace". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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