Rollback question

Rollback segments

Hi,
I have read the documentation on the rollback segments and just wanted to get a good hold of it!

If I have 1 rollback segment,with Initial 2M next 1M minextents 20 maxextends unlimited then

1) If 20 people log in simultaneously, will each get a separate extent?.
2) if there are 40 People, will the system extend once for every addition user or assign each to the existing extents?
3) Can there be two users using the same extent.
4) In the above case -Next is 1m, does that apply only if the transaction that was assigned to a extent wants an additional extent.

Please clarify
Badrinath

An extent within a rollback segment can be shared/used by multiple transactions.

Hi

Well none of it is true.....Hmm the magic number 20..dunno how did they arrive at this number..;-)

regards
Hrishy

you should use same initial and next size

AFIAK extent can be shared by several users, that if it´s the frst extent

for example if I have a transaction which uses 2 extents then the second extent is exclusively used by this transaction