how to clear cache

Hi Ng,

i use allesandros mandragora with ojb in "mixed-mode".
It is working fine, but when i remove objects with mandragora and then 
read the again with ojb, i get the cached object back, not the one, what 
hase been saved.
When i restart my app, then i get the right object.
So, how can i clear the ob cache (or whatever, to get the right data :-) ) ?

Hans