-int dbfn_delete(open_db *, uschar *);
-open_db *dbfn_open(uschar *, int, open_db *, BOOL);
-void *dbfn_read_with_length(open_db *, uschar *, int *);
+int dbfn_delete(open_db *, const uschar *);
+open_db *dbfn_open(uschar *, int, open_db *, BOOL, BOOL);
+void *dbfn_read_with_length(open_db *, const uschar *, int *);