The present disclosure describes methods, systems, and computer program products for performing JOIN value comparisons. One computer-implemented method includes converting, by operation of a computer system, a first value of a first data type into a second value of a second data type, wherein the first value is a value of a first attribute of a first table; converting, by operation of a computer system, the second value of the second data type into a third value of a third data type; converting, by operation of a computer system, a fourth value of the third data type into a fifth value of the second data type, wherein the fourth value is a value of a second attribute of a second table; converting, by operation of a computer system, the fifth value of the second data type into a sixth value of the first data type; and performing JOIN operations of the first table and the second table in response to determining that the first value equals the sixth value, and the fourth value equals the third value.