Re: backup and recovery in data warehouse

Thanks for the replies. To answer a few of the questions raised.

This data warehouse will be at least 1.5 TB in size that's why we can't do nightly cold backups. Having some read-only tablespaces will reduce the amount to backup. But I expect that we'll never be able to backup the entire database in one go even excluding the read only tablespaces. Exports and imports will just be too slow.

We're thinking of NOT running in archive log mode. Being a data warehouse users will only be performing reads. The only updates/inserts will be performed during the loading of data, which can be reloaded if there are any problems. Having archiving turned off will improve the performance of this. So I can't see the point of running in archive log mode. Nice in theory I know so this may change in the future.

On the tablespace sizing and creation. We're going to be partitioning by month and each of these partitions will be in a seperate tablespace. So how do we know how big to make each tablespace and when should they be created? If we guess at the size and they're too small then we'll have problems, too big and we're wasting space. That's why I suggested using autoextend. And should I create them all for say two years before they're needed???

Thanks again.

Jeremy

In article <389B14B3.93302673_at_wolfenet.com>,   Jeremiah Wilton <jeremiah_at_wolfenet.com> wrote:
> You can cold-backup any subset of tablespaces you want. As long as
you
> use archivelog mode, there is no requirement to backup the whole thing
> associated with the type of backup being used (hot/cold).
>
> For instance, if you have two tablespaces, but only enough time to
back
> up one each night, you can back up the first one one night and the
other
> one the next night. When it comes time to resore/recover, you restore
> the two nights' backups, then roll forward until they are consistent.
>
> The question I have is: why would the user want to use cold backups
> instead of hot backups?
> --
> Jeremiah
>
> Brian Peasland wrote:
> >
> > If you are doing cold backups, then you should backup the entire
> > database. If you want to back up different tablespaces on different
> > nights, then use hot backups. Alternatively, you can also use
exports.
> > To find information, check out Oracle8 Backup and Recovery from
Oracle
> > Press. Or Oracle 24x7 also from Oracle Press.
> >
> > jeremycdba_at_my-deja.com wrote:
> > >
> > > I'm looking for information on a backup and recovery strategy for
a
> > > data warehouse. I'm thinking of using a combination of read-only
> > > tablespaces and incremental cold backups, ie backing up different
> > > tablespaces/datafiles each night. I can't find any case studies or
> > > specific examples of this method and would appreciate information
or
> > > pointers to documents, articles or white papers etc.
> > >
> > > I'm using Oracle 8i on Unix Solaris.
>

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Before you buy. Received on Sun Feb 06 2000 - 20:27:58 CST