DSXchange

Hi;
i am new to mainframes and would like to have help from folks in this regard.
1) when do you go Complex flat file
2) when do go for regualr flat file
3) merits and demerits of one over other.

Use a normal sequential flat file whenever you can; it is simpler, easier and more efficient. Some COBOL structures cannot be read in a sequential file stage, for example anything with an OCCURS DEPENDING ON, and you need to use the complex stage to process these types of files.