> A bigint would be overkill since it is not a 64-bit value. So, a int/bigint
> field can legally store hexadecimal values?

Store ? "hexadecimal" is just one of many possible representations/formatting
of values. i.e. number 10 can also be represented as
00000000000000000000000000001010 (binary), or
00000000012 (octal), or
000A (hexadecimal), etc.
Or do you really need (why?) to pass string with hexadecimal value and let Firebird
to convert it automatically ?

Ivan