For flat files, the Integration Service reads data with a Number datatype as it appears in the file. If you want to specify decimal precision and scale, use an Expression transformation to convert number ports to decimal ports. Also enable high precision in the session.
For example, if the flat file contains a 5-digit numeric field called Price, and you want to output the Price as a number with two decimal places, you would set up the following expression:
PRICE / 100
This expression moves the decimal place two digits to the left as shown in the following example: