SPI_getbinval — return the binary value of the specified column
Datum SPI_getbinval(HeapTuplerow, TupleDescrowdesc, intcolnumber, bool *isnull)
SPI_getbinval returns the value of the
specified column in the internal form (as type Datum).
This function does not allocate new space for the datum. In the case of a pass-by-reference data type, the return value will be a pointer into the passed row.