size of DB files not decreasing

hello all ,

While deleting the entries from openldap- Database I see that there is no change in the file size .
I did an external checkpoint using db_checkpoint -1 and db_archive -d .
The changes are reflected fro an add operation but it is not reflected for delete .

I have a requirement where I need to externally poll the size of DB for openldap .
But delete operation is not making any changes to actual DB file size .
I am not sure if its a BDB limitation or something to do with the way openldap is being configured .

Please help in understanding .

regards

Nikhil