When a UNION operation involving DECIMAL datatypes with scale and digits
before the decimal exceeds the currently supported maximum precision
of 38, we throw an error to the user:
"MCS-2060: Union operation exceeds maximum DECIMAL precision of 38".
This is until MCOL-5417 is implemented where ColumnStore will have
full parity with MariaDB server in terms of maximum supported DECIMAL
precision and scale of 65 and 38 digits respectively.