>From the docs : Many active transactions can write concurrently to a single rollback segment--even the same extent of a rollback segment; however, each data block in a rollback segment's extent can contain information for only a single transaction.
1) Now, when oracle writes to the last extent in the cycle, and sees that the first extent has an active transaction, it allocates a new extent. Well, why should it? Cant it write to the first extent? 2) When a new transaction needs to use the rollback segment, and say it gets allocated to a rollback segment with a few other transactions, how does it decide which extent to use from the cycle of extents? Thanks Raj -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).