Re: UNDOTBS + ARCHIVE LOGS

"chris_f_clark" <chris_f_clark_at_hotmail.com> wrote in message news:686d9267.0401171616.5c1988d9_at_posting.google.com...
> I am a 'Newbie' to Oracle (we have 9i) and have been doing a lot of
> reading about these two features but still can't get a clear idea
> about them.
> My understanding is that UNDOTBS is automatic undo segment generation
> that ORACLE now recommends and REDOLOGGING is the manual rollback
> segment option. If ARCHIVELOGGING is set on, archvive log files are
> created when the REDO LOGFILES are filled up. Does this still happen
> if you are using the automatic UNDOTBS way? or does it mean that
> ARCHIVELOGGING is only possible when you have selected the manual
> option. Therefore if this is correct this would mean using the
> automatic UNDOTBS option would only cater for instance recovery and
> not allow a full media restore.
> In essence my question is, can you have the automatic UNDOTBS and also
> have ARCHIVELOGGING?

The redo logs are for recoding transactions. When they fill up there is a log switch. If the database is in archivelog mode (good idea) then the redo log that filled up is copied to a file called an archive log. (a new name is generated for each one). The undo tablespace is for holding what used to be called rollback segments (a copy of the data that existed before the transaction started.) So instead of you allocating and possibly administrating rollback segments in a rollback tablespace you now allow Oracle to bascially manage it in an undo tablespace. So yes, you can have archive logging and an automatic undo tablespace. Jim Received on Sat Jan 17 2004 - 18:25:19 CST