ORA-30036: unable to extend segment by string in undo tablespace "string"   tips

It is important to note that ORA-30036 is associated with UNDO tablespsaces.  If you use autoextend on an UNDO tablespace  because you can easily run out of UNDO and receive ORA-30036 along with an aborted update. For a full note on UNDO sizing, check here.

Oracle MOSC also has information regarding ORA-30036 and UNDO when it occurs after an abort shutdown.

Question:

I received ORA-30036 after a shutdown.  A job was killed so that we could reboot after it had been runing for a while.  We issued the shutdown command but the database didn't stop and then had shutdown abort.  Now, trying to restart we get this:

Errors in file /u0704/oracle/proddb/9.2.0/admin/PROD/udump/prod_ora_16213.trc:
ORA-30036: unable to extend segment by 8 in undo tablespace 'APPS_UNDOTS1'
Error 30036 happened during db open, shutting down database
USER: terminating instance due to error 30036
Instance terminated by USER, pid = 16213
ORA-1092 signalled during: ALTER DATABASE OPEN...

Answer:

The workload had been running for 12 hours  and caused a workload spike.  You received ORA-30036 as the transaction attempted to recover in startup, which caused you to met the UNDO limit.  The ORA-30036 error is thrown as the database refuses to open. 

You can resolve ORA-30036 by first mounting the database and disabling UNDO:

alter system set undo_management = manual scope=spfile;

Next, you must shutdown to resolve ORA-30036 and then startup again using rollback mode and a system rollback segment.  Use UNDO tablespace to add files and then use alter system set undo_management=auto scope=spfile; to activate the UNDO once again.  To fully resolve ORA-30036, shutdown and restart again.