> > > 1. Have you found Incremental backups and Change Block Tracking to be > reliable; i.e, can you reliably backup and then restore and recover? > > >> For dozens of our business critical databases we are doing an > incremental/cumulative incremental backups and we have had no issues whether > with back or recovery scenarios. Indeed we have benefited with BCT on our > historical database (data warehouse). It drastically reduced our backup > time. > > 2. What about Oracle compression during an RMAN backup? Is that reliable? > > >>As you knew that an RMAN (pre 10gR2) comes with NULL compression > facility. You really need to test the binary compression and then decide. If > binary compression works good with somebody, may not fit exatly into your > env. I think R&D would be a good choice. > 3. How much of a performance hit using the Change Block Tracking feature? > What about Oracle compression? > > >> Oracle says that definately there is increase in the CPU usage while > performing compressed or BCT feature. May not be very highy. > > 4. Do you know if any of these features are additional cost? Do you know > if there is a view in Oracle that outlines what features come with EE and > what features are additional cost? > > >> If I am not wrong, there is an additional cost involved. (please > correct me) > > 5. We also have the option to do compression at the tape drive level. Is > anybody aware of any reason that Oracle compression (during backup) would be > better or worse than letting the tape drive do it? > > > > 6. I have read that restores of a cumulative backup a generally faster > than restores of a differential backup. What makes cumulative faster? Is > it simply that RMAN will just one incremental file to restore and recover > from (plus archive logs)? If there are six differential backups to recover > from, RMAN should be able to restore and recover the six files without DBA > intervention. I don't see a significant time difference. Perhaps a couple > minutes extra because it has six more files to deal with? > > The other fact is that cumulative backups takes more time than > differential backups. I guess, Advanced RMAN document will be handy for more > calarity. > > Thanks for your input! > > > > *Sam Bootsma* > > *Oracle Database Administrator* > > *Information** Technology Services** > George Brown College* > > *Phone: 416-415-5000 x4933** > Fax: 416-415-4836** > E-mail: **sbootsma@xxxxxxxxxxxxxx* <sbootsma@xxxxxxxxxxxxxx> > > > -- Best Regards, Syed Jaffar Hussain Oracle ACE 8i,9i & 10g OCP DBA RAC Certified Expert Official Oracle RAC SIG Representative for Saudi Arabian region ( http://www.oracleracsig.org/) http://jaffardba.blogspot.com/ http://apex.oracle.com/pls/otn/f?p=19297:4:1579866181463918::NO:4:P4_ID:126 ---------------------------------------------------------------------------------- "Winners don't do different things. They do things differently."