9i DataGuard

I have two Sun e450 servers running Oracle 8.1.6.3. One is used for OLTP
(Production plus 3 other instances) and the other has the Data
Warehouse (same number of instances). All databases are exported daily and have Cold Backups Monday-Saturday. The Production OLTP database is about 9 months old. It is now just over 50Gb, and is expected to reach about 70Gb once a year's worth of data has been created. It is expected to hold 2-3 years' worth of data before we start rolling data off. Virtually all DML occurs during nightly Batch processing. Nightly processing volume has grown to the point where it and the nightly Cold Backup can no longer peacefully coexist. Something has to be done, and soon. Here is my plan:

Monday-Friday Hotbackup of Prod OLTP database directly to tape. All databases will continue to be exported daily. At night, do a log switch on this database and then backup Archive Logs, export areas, O/S areas, and Oracle disk to tape.
Saturdays Cold backup of all databases, export areas, etc. The data warehouse box will continue to have Cold Backups Monday-Saturday as before.

My concern here is with recovery time. Since I will be doing a Cold Backup every Saturday, at worst 5 days' worth of Archive Logs would need to be applied. But that could still mean many hours of downtime. I have been doing a lot of reading about 9i DataGuard and all the improvements to the Standby Database concept. I am planning on migrating these boxes to 9i in the next 6-12 weeks. I talked to my SysAdmin yesterday about sticking an extra NIC into each box, and directly connecting them together. Then I could create a Listener on each box dedicated to keeping the Standby database in sync with the OLTP database. My hope is that by doing it this way, the impact of the Standby
database would be minimal. Of course, I will still need disk space on the data warehouse box to accommodate a Standby database that may get as large as 210Gb. I find the rapid recovery options with DataGuard very appealing. I also like the fact that the Standby database can be opened up to queries. My concern is that my client is a cash-strapped govenrment entity with very very few $$$. That is why 9i RAC is not considered - the licensing is too expensive!  It will be difficult enough for them to come up with the $$$ for NICs
(much more expensive for a Sun than a PC, around $950 each) and
additional RAID arrays.

My questions - is this a sound backup plan? Is anyone out there using DataGuard - does it work as designed? Pitfalls to be aware of? Also, if using DataGuard, should one still do weekly Cold backups? Nightly exports?

TIA joe Received on Thu Apr 11 2002 - 15:03:44 CDT