Recently, our DBA suggested that DB2 z/OS v. 8 can perform the reorg while the online application is still running/when the update batch cycle is running. My understand was that the online utilities in version 7 and 8 can save some time.

However, back in December when we were running v 7.1 of DB2, DBA did attempt to run the online UNLOAD when the online application was up. The result was a disaster. Several of our table indexes were corrupted, the application went down for over a week while DBA was trying to explain what went wrong. And up until today, I still do not have a clear explanation of what went wrong. So when they suggested this, I was quite skeptic. I spoke with another DB2 programmer who has a friend that told him that the utility works fine provide that the application use RI. I take that he referred to "referential integrity". This is where I need some help - all the tables in our application do not have "primary key" setup, and there is no reference in the application between tables. Tables are joint by the application logic. Will the online reorg work?