xo_type
xo_type is an object with the following attributes:
• int type – Identifies the data type of the column
• int length – Contains the maximum length for a character data type.
• int prec – Contains the number of digits of mantissa precision.
• int scale – Total number of significant digits to the right of the decimal point.
• int radix – Radix of PREC if TYPE is one of the approximate numeric types.
• int null – Contains 0 (XO_NO_NULLS) if not nullable, 1 (XO_NULLABLE) if column is nullable.