Re: Super easy ? for you gurus

In article <33734135.6BF8_at_saxe.com>,

        JP Soria <jpsoria_at_saxe.com> writes:
>Our database is actually a datawarehouse 300+ gig. We are not running
>in archivelog mode.
>My question: Why does the database need to be shutdown in order to
>perform a backup? Isn't it a read only process as far as the DB is
>concerned?
>Most of the data is historic and therefore static. Users are not able
>to add, insert or delete.
>Any answer is greatly appreciated.

I assume then that you've defined ALL the tablespaces (except SYSTEM and TEMP) to be read only? If so, and a complete cold backup exists from some point after read only is activated, then you would only need to backup SYSTEM, TEMP, and redo logs during subsequent shutdown  ... and that's the answer to your question. Read transactions also change the indicators in the fiel header blocks in TEMP and the REDO areas. If you don't shut down ORACLE, you'll have an inconsistent snapshot. I ran experiments on this back a few years ago (ORACLE 6). Everything worked fine for about 100+ shutdowns, and then we could no longer bring up the database without DROPping tablespaces, meaning a total loss of data. ORACLE's export with the consistent option is far safer. Let's not forget that export/import are not really adequate for backup/recovery. There IS a reason that hot backup exists ... read up on it in your CONCEPTS manual.

Bill

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