Big deal wth CMOd

Question

hi
1)  when and where do we use delta full and initial update.. in moniter or when extractiong?  (Must understand the 'init,delta, and full load' types of loads and when to use which. )
2) abt CMOD .. i know how to write the code in ABAP.. but my main question is
first
  when u go for lis extaction... there u select data source and  the fileds u need.. ex:  data source  2lis_01_s760 (2lis_01_s260 may be this is already in BC) (forget what ever data spurce)
ok if i need to add external field.. where  shuld i mention abt it../....... if u just write code in CMOD.. system will take it by default.. and how system knowss..please help in this case
if the adding field which is in DB hwo to add it to the data source?
if the adding field is in Excel file.. How to add it to the data Source..
if the adding filed is in another data source how to our data source..
please help me
kasinath
kasinath

Answer 1

2:
1. Enhance your extract structure (RSA6 - 'Enhance ExtractStructure') with a 'ZZ'-field
2. Add your code to the user exit (RSA6 - 'Function Enhancement)
If your additional field was in an Excel file, it should be uploaded from Flatfile. You can merge both sources by using an ODS