Rollback Segment

[Chandra]

Hi,
i would like to know "why" do we select "pctincrease 0" when we are creating the RBS.

Thanks

[sambavan]

This was b'cos you want the extents to be consistent. If you get to set the pctincrease to 50 then what it would mean is that percentage of increase is 50% as a result say initially your extent is 100M then when this 100M gets filled up, oracle would incease it to (.5 * 100). Next time when this 50 is filled up oracle would add (.5 * 150) and now your total table space would be 150 +75 = 225. next set would be 225 + (.5*225) =337.5M

That is why we set the pctincrease to 0 to prevent the fragmentation. Hope this would clear you.

Sam

[sreddy]

Why do you want to store instantaneous data changes thats valid until the transaction completed, creating fragmentation there by not having extents growth for other transactions in RBS specifying some PCTINCREASE ?

Not sure, My Q here is like an answer for your Q. Isn't it ? SORRY, if you think I'm confusing you...



[Edited by sreddy on 03-08-2001 at 01:16 PM]

[sambavan]

O.K. It looks like oracle had enforces it as a restriction, that PCTINCREASE cannot be specified for the rollback segment and it had been set to 0. The reason as suggested earlier, since it is being used heavily, it would cause a v.high fragmentation.

Sam