As I try to combine 2 tables by using LEFT KEEP instead of JOIN and try to STORE it in a QVD I find that the fields from the 2nd table are missing from the QVD. Why so? What I need to do to use Keep and bring all fields into the QVD?
'Keep' is basically used to restrict the records in one table based on common values in other table. It doesn't join two tables, and just does the job of deleting records based on the key word 'left', 'right','inner' etc.
You have used 'Left keep(First table)' so your 2nd table will have only records which are matching with the first table, rest of the records of second table will be removed from 2nd table, but no fields of second table will be added to first table.
So it does the job of data reduction in one table based on the common fields and values in other table.