March 2010- Unintended Consequences
We’ve all done it. You see a great new feature in DB2 and jump headling into using it without fully appreciating all of the implications. Here’s a case in point:
One of our clients is a large SAP customer running on DB2 for z/OS V9. With a huge number of subsystems to support and over 35,000 tables in each, taking traditional image copies would be a bit of a nightmare. Luckily, DB2 9 for z/OS contains the BACKUP/RESTORE SYSTEM function, which uses Flashcopy technology to rapidly backup and restore an entire system with a single utility. That means no messing with the traditional tablespace-level COPY utility, except when it’s needed for other reasons (such as when taking an inline image copy during an online REORG, to avoid putting the tablespace into COPY PENDING).
So far, so good. However, a couple of weeks ago the DBAs came in one morning to find a lot of SAP users complaining about database errors, and dozens of tablespaces unable to be updated due to being in a COPY PENDING state. What the heck happened?