[ZODB-Dev] Heavy size increasing of database after adding an object

[Manuel Markwort]

I adding my own ZClass Objects in the data.fs. After adding a new 
instance of those objects the database size increases heavily in 
opposition of the real object size. Before I add the instance to the 
database it's size is 26.6MB, after commiting the transaction the size 
is about 26.9MB. After packing the database the size is 26.6MB again. 
What happened in the background? It is possible to avoid this high 
increasing of the database without packing after adding the object?