Re: Why does Orcl generate REDO logs in NOARCHIVE mode?

Mike,

So you always restore your last cold backup on a power failure? I attempt to start the database, see it roll back uncommitted transactions, an it is up and running. Remember that uncommitted transactions are written to the datafiles directly. Your RAM-disk redo-logs are gone. While you are reading tapes, I am going home and enjoy my weekend.

I agree that backing up the redo logs is useless. Using them is useful.

About running batch jobs...when you change data on robust multi-user databases, expect IO's. Use your OS concurrency on disk access paths and spread your datafiles among multiple physical disks. Use multiple dbwriters (1 per used physical disk). Agree that IO's are bad news on any system, not that they can and be avoided

>I still think Oracle writes twice as much data to the redo logs than it
>needs to
>because rollback info gets logged too. But that's another story.

What do you mean by 'rollback info gets logged too' ? Consider:
User a modifies but doesn't commit
User b reads data before User a changed it.

You try to implement this without storing the before state of a transaction in a multi-user database.

JM Received on Wed Mar 24 1999 - 17:11:01 CST