Onkar - You are correct, that the data blocks your transaction is modifying are all using RBS01. You have thusly commanded Oracle. But that just has to do with modifying blocks. As Jeremiah points out, the ORA-01555 is caused by READING from the database. When other transactions have modified blocks that you need to read, those transactions may have used other rollback segments. Read the article, it is less than a page long. Dennis Williams On 6/3/05, Onkar N Tiwary <onkarnath.tiwary@xxxxxxxxx> wrote: > Lex/Dennis, > Thanx for the suggestion but my main query is why my transaction is not > using RBS01 when I have set the same for the current transaction?? No dou= bt > u guys are absolutely right but when I am setting the transaction to use > RBS01 then it should use that only and not the other rollback segment(if = I > am not wrong). -- //www.freelists.org/webpage/oracle-l