Mark, Thanks. Yes, we will have to go to 9.2.0.5 but I would be insisting on testing the application and the indexes -- the vendors who designed the application don't encounter the ORA-600 [12700s] at their test site even in 9.2.0.4 probably because they don't have the same level of concurrent updates as we have in the Live environment [and we're not sure we can create the same level in our own Test environment] In the meantime, I will attempt using Jonathan Lewis's simple exception-in-a-loop method. 10g is not under consideration currently. Regards Hemant At 06:19 PM Saturday, you wrote: >Hemant, >Actually, in 10g, there is "ddl_wait_for_locks", which defaults to >FALSE. I've not yet experimented with it, so, I won't comment, other >than to speculate that it will do what you want. > >It really sounds like an upgrade to 9.2.0.5 to avoid the rebuilds in the >first place is the right answer. A while back, someone had a similar >requirement, and I suggested use of DBMS_LOCK. Use it to create a UL >enqueue. Write your code so that any code that does DML against the >table that the index is on takes a share mode lock. Lots of concurrent >DML would be able to take the share mode lock. When it's time to run >the rebuild script, have it take an exclusive lock. If there is any DML >running against the table, the request for exclusive lock will wait, >queued behind the share locks. When the DML completes, the exclusive >lock will be granted, and you can do the rebuilds without fear of >ORA-0054. When the rebuilds complete, release the exclusive lock, and >any DML which queued behind the exclusive lock will run. > >But, I think it's a lot easier to upgrade to 9.2.0.5 or 6. And, if you >run across any kind of similar requirement in 10g, "ddl_wait_for_locks" >is probably worth a look. > >Hope that helps, > >-Mark > > >Mark J. Bobak >mark@xxxxxxxxx >"Science is the belief in the ignorance of experts." --Richard P. >Feynman > > >-- >//www.freelists.org/webpage/oracle-l Hemant K Chitale http://web.singnet.com.sg/~hkchital -- //www.freelists.org/webpage/oracle-l