Re: Transaction without redolog

Short answer: no. You're asking for the one mechanism we have to ensure data security to be switched off. Oracle simply won't allow you to do that.

However. The slightly longer answer is that it depends on what your PL/SQL program is actually doing. Certain operations *can* have their redo switched off, because there are alternative mechanisms available to ensure data security. For example, 'create index' statements can be done with the 'nologging' attribute, because if anything happens to the index, it can always be rebuilt, therefore it doesn't need redo to protect its data.

Similarly, 'create table blah as select * from blahold' can be done nologging. If anything happens to BLAH, BLAHOLD is still safe and sound, and we can reconstruct BLAH from it, without recourse to redo.

So there are some special DDL and even more special DML statements that can be done 'nologging', but good old inserts, updates and deletes can *never* be done nologging.

Unless.... unless.... you want to take your life in your hands, and risk your entire database becoming utterly unrecoverable (and do something which is totally unsupported by Oracle to boot).... there is a hidden parameter which can be set in the init.ora called "_disable_logging". Set that to TRUE, and absolutely nothing will be logged. Ever. But you'd better pray you've got bloody good backups before using it, and whilst you're at it, pray that you never have an Instance crash -because you won't be able to recover from it.

One site I worked with had a big batch update performed once a month, with cold backups taken immediately before and after. For them, _disable_logging was a perfectly viable option, and it made the update take place at something like three times the speed than before. If anything awful happened, they happily signed up to the loss of the update, and reverted to their previous cold backup. So there is a use for it, but you really need to know what you are doing, and the potential costs involved.

All of which basically amounts to: stick with the short answer. There's nothing you can do about it safely if its ordinary DML you're performing.

Regards
HJR "Elías Alpuente" <ealpuente_at_isoco.com> wrote in message news:a14gn0$nb7$1_at_talia.mad.ttd.net...
> We have a PL/SQL program that generate a lot of redo log data. Each time
the
> archiver
> make its job we have 3 Gb in the arc directory.
>
> Is posible make a transaction without generate redolog data with
ARCHIVELOG
> mode?
>
> Thanks.
>
>
Received on Fri Jan 04 2002 - 15:09:54 CST