Re: How to deploy a 24hrs , 7 days a week kind of database environment?

"Sunny Wong" <sunwong_at_yas.com.sg> writes:

>Can anyone pls tell me what type of strategies shall I use in order not to
>have any downtime?
>What are the recommended backup strategies?

While I recognize that some environments really do need absolute 7x24x365, but I would venture that a large percentage of these demanding environments could live with that 24 being 23.96; if those 2 minutes come at predictable times. If you can live with 2 minutes of Oracle downtime per day, you could have daily offline backups and your recovery would be much less painful. To do this you could use disk mirroring (three in a group is best). Shutdown the database at some pre-ordained time, remove one of the three copies from the disk mirrors and then re-start the database. The operation would take 2 minutes or less (depends on the machine / OS). Then do your backup from the split mirror. Once your backup is finished just re-sync the third copy with the rest a keep on going.

I run a '7x24' environment this way. The user base knows when the two minutes will happen each day and the business deals with these times.

Since 7x24x365 means no upgrade or recovery downtime, I'd live in fear of almost everything and test the recovery every week. I liked the idea of three swappable boxes for this kind of thing. They better all be in different physical locations, far enough apart to have separate power sources too.

Just my rambling thoughts on the matter.

Casper
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Paul Schenk 		schenk at nbnet dot nb dot ca
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