extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
extern int bt_findkey (BtDb *bt, unsigned char *key, uint keylen, unsigned char *value, uint vallen);
extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
extern int bt_findkey (BtDb *bt, unsigned char *key, uint keylen, unsigned char *value, uint vallen);
extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);