Hi all, I have a very long running process which causes the Zope process to eventually eat up all the RAM in my PC. I have tried changing the object cache sizes to no avail. Zope sticks to the cache parameters fairly well (it doesn't overshoot the target by much). The number of ghost objects do keep on increasing, however. Does a ghost object use the full amount of RAM (for that typical type of object) or is it only an empty shell? How do I get Zope to delete/unload these objects manually? B.t.w. I have tried numerous ways to do the long running process including: One thread that get_transaction().commit() every now and again Get new thread, do a few transactions, commit, close thread, wash, rinse, repeat (yes, I know the pitfalls with opening new threads into Zope - I end up reusing one connector from the pool over and over again). The above made no difference to the fact that eventually, memory will run out. The process makes changes to many objects and creates many new objects. It takes a long time to complete (typically a day or more). If I know the ghost objects does not use up memory, I can hunt for memory leaks in my own code, but currently the only thing that increases and increases is the number of ghost objects. Thanks Etienne