when tried reading records from both delimited files or database, the "length" of the records specified in schema seems irrelevant, whatever the length specified talend still reads the whole record? why is it so?
As I understand it, for numbers Length is the total number of digits and Precision is the number of digits after the decimal point. Usually numbers have a precision and scale where precision is the total number of digits and scale is the number of digits after the decimal point. Talend instead labels those Length and Precision respectively for numbers. Don't know why they seem irrelevant in your scenario.