-typedef void (*DBAPIQuery)(struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *, ...);
-typedef void (*DBAPICreateTable)(struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *, ...);
-typedef void (*DBAPILoadTable)(struct DBAPIConn *, DBAPIQueryCallback, DBAPIQueryCallback, DBAPIQueryCallback, DBAPIUserData, const char *);
+typedef void (*DBAPIQuery)(const struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *, ...) __attribute__ ((format (printf, 4, 5)));
+typedef void (*DBAPISimpleQuery)(const struct DBAPIConn *, const char *, ...) __attribute__ ((format (printf, 2, 3)));
+typedef void (*DBAPIQueryV)(const struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *);
+typedef void (*DBAPICallV)(const struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *, const char *);
+typedef void (*DBAPICreateTable)(const struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *, ...) __attribute__ ((format (printf, 4, 5)));
+typedef void (*DBAPICreateTableV)(const struct DBAPIConn *, DBAPIQueryCallback, DBAPIUserData, const char *);
+typedef void (*DBAPILoadTable)(const struct DBAPIConn *, DBAPIQueryCallback, DBAPIQueryCallback, DBAPIQueryCallback, DBAPIUserData, const char *);