op.key_size = (force_key >= -1) ? force_key : src->root->key_size;
op.val_size = (force_val >= -1) ? force_val : src->root->val_size;
dest = sdbm_open(&op);
op.key_size = (force_key >= -1) ? force_key : src->root->key_size;
op.val_size = (force_val >= -1) ? force_val : src->root->val_size;
dest = sdbm_open(&op);