Our DBA told me that it's a bug in 11g, but it's easily fixed. The solution is to enable an event in the init.ora file and reboot the system. It didn't sound like you had a full-time DBA for your project, so I got a few simple instructions from our DBA to help you out.
- create pfile from spfile
- modify pfile to include the event
- startup using new pfile
- create spfile from the new pfile to put new event into spfile for next reboot
44951 TRACE NAME CONTEXT FOREVER, LEVEL 1024
This fix causes ASSM LOB space to batch up reclaim instead of just reclaiming the requested/required number of LOB chunks. To enable this fix, set event 44951 to the maximum number of chunks that you would like to have reclaimed per attempt. The maximum allowed is 1024. Anything larger becomes 1024. However, if the requested amount of space is larger than the event’s value, the reclaim will be for the requested amount of space.
Good luck!