No updating value when key exists

[ian-g-holm-intel]

Why is it that when I do a put with a key that already exists, it doesn't update the value for that key? Do I have to delete the old key/value before adding the new key/value?

[ian-g-holm-intel]

It appears that my val is not getting written to the db. But the dbi.put is returning true. Is there something special you have to do to use lmdb::val?