Can't modify DBM key

Hi. I have the following problem: When I run this script, "TestValue" appears on the screen (but it should not): $file = dbmopen("test", "c"); dbminsert($file, "TestKey", "TestValue"); dbmclose($file); $file = dbmopen("test", "c"); dbmdelete($file, "TestKey"); dbmclose($file); $file = dbmopen("test", "c"); $data = dbmfetch($file, "TestKey"); echo $data; dbmclose($file); You see, "TestValue" should not appear on the screen because the key has been deleted with "dbmdelete". After the call, the database files are modified. But they don't get smaller but bigger! Is this OK? Shouldn't they get smaller when I delete something? Will the files grow for ever? Does an optimization function exist for DBM files? Why is the key not deleted? Thank you David Scherfgen