(operators 1)
PostgreSQL
Object Relational DataBase Management System

演算子の拡張(1)
C言語演算関数
Complex  *complex_add(Complex * a, Complex * b)
{
    Complex    *result;
    result = (Complex *) palloc(sizeof(Complex));
    result->x = a->x + b->x;
    result->y = a->y + b->y;
    return (result);
}
演算関数の登録
CREATE FUNCTION complex_add(complex, complex)
    RETURNS complex
    AS '$PWD/obj/complex.so'
    LANGUAGE 'c';