RB and fragmentation???

[jlakhani]

Can roll back have fragmentation?
I have a RB tablespace which is 74% full. It has 500 MB fre space and the big chunk is 30. We have over 9 datafiles in the tablespace and its @ 94 % fragmented. Can rollbacks have fragmentation and if yes how do i figure out which specific rollback is most fragmented?

thanks
Jigar

[marist89]

Yes and no. If your RBS are created with a different INITIAL and NEXT extent values, then yes you might have a little fragmentation. Otherwise, the pctincrease value for all RBS is 0. While you may have alot of extents, they probably are the same size.

[mbaliga]

Hi,

You can query the DBA_ROLLBACK_SEGS to verify the initial, next extent sizes. If they are different for different segments then you will have fragmentation. Then it would be a good idea to recreate the RBS tablespace & segments. You can minimize/loadbalance the datafiles to distribute I/O.

Baliga