Re: waits on only one rollback segment

Joani,

Check if the second rollback segment is online. You can select this information from the dba_tablespaces table (you do need to have dba privilege's).

Succes,

    Ger.

Joani Tamminen <joani_tamminen_at_yahoo.com> wrote in message news:11f13276.0206051241.66efbb90_at_posting.google.com...
> We find the following problem on one of our production databases. This
> is my colleague's description about the problem: We are running Oracle
> 8.l.7.0 on AIX 4.3.3
>
> ------------------------------------------------------------
> We have a database with 4 rollback segments. Each rollback segment is
> on each separate rollback tablespace. Each rollback tablespace size
> 1500M. During monitoring, I saw many waits on one of the rollback
> segments rbs2.
>
> Then I added two more rollback segments in a new rollback tablespace -
> each of them about 650M.
>
> I still see lots of waits - the strange thing is the waits are only
> one rollback segment rbs2. I do not see any waits on any of the other
> rollback segments. I looked at the v$waitstat table for "undo header"
> before and after adding the new rbs segments and I see almost the same
> number of waits.
>
> I am watching the waits every hour and find that waits on rbs2 is
> usually 1938 or 1939 while all the other rbs (rbs1, rbs3, rbs4, rbs5,
> rbs6) are close to 0.
>
> My question is: why are waits happening only on rbs2? What am I doing
> wrong?
>
> --------------------------------------------------------------------------

--