About a month ago, due to some communication problem with ASM instance, block_change_tracking was automatically disabled by oracle. Since then the only impact I see is the slow rman backup. It used to take 10 hours and now it takes 40-48 hours. I want to enable block_change_tracking again but I am a bit cautious as it is a production server.

I have following questions :
- If I enable block_change_tracking, will I have any side affects on the system apart from normal overhead cost that comes with this service and is it safe to do it any time ?
- Can I just enable it and RMAN will notice it next time when it runs the incremental backup or should I enable it just before starting an incremental backup ?

Hi,

>> About a month ago, due to some communication problem with ASM instance, block_change_tracking was automatically disabled by oracle.

That's a serious production emergency. Is your database recoverable?

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>> It used to take 10 hours and now it takes 40-48 hours.

And you cannot tell why? I'm guessing that RMAN is doing a full backup now . . . .

You need to get an RMAN expert to look into this.

Call Oracle at 800-223-1711 and tell them it is a production problem.

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>> is it safe to do it any time ?

No, it is not safe. You must understand all of the details and remifications.

Read this carefully:

http://www.dba-oracle.com/t_block_change_tracking.htm



You may get it to turn-on but TAKE THE TIME TO TEST A RECOVERY.

If the database cannot be recovered you could lose your job!

Good Luck!