Thank you Isotope.
The other reason why I wanted to know which rollback segs are being currently used because I am trying to make scence of my rollback tablespace being 60% occupied. Is the space taken by the rollback seg's currently used? If not, how does my rollback tablespace get filled?
Coalesce the ts and re-check. Are the rbs created with optimal storage parameters or initial and next?? In the latter case, the rbs will grow and remain large (esp. after a large transaction has completed) and would not free up space. In the prior case, the rbs will shrink to the optimal size after the trans. is over.
So, the occupied bytes in my rollback tablespace is acive rollback seg's with or without optimal parameter and inactive rollback seg's shrunk to the size of optimal. Is it correct?
In that case when the database comes up before any transactions took place and users logged on the tablespace used for rollback segments would be almost 100% free. Again, is it correct?
In my case I do have optimal set. I am just trying to get a general idea.
Yes. For example: say a rbs size of optimal 1M and has been created. If a transaction uses this rbs and undo of about 2M is generated, the rbs will grow to 2Mb. Upon commit/rollback, it shrinks to optimal size (1M).