I have a CRM and I manage subscription. Now I wonder what is the better way to to store information for each person on each participation of a send out of a subscription. Or in other words: Each month I send out a magazine to thousands of persons. And I want to be able to "see" at each person which of the monthly send-outs he got.
I think on way to do so is to have a separate table and store for each subscription send-out a record (M:N like ID_person, ID_send_out_action).
Another way could be to store all IDs of persons of a send out action in a field, each ID of a person per line.
In the recordset of the person I can have a portal that can use both ways to show the send out action participation of the person - while relation the ID of the person to the ID_person of the MN-relation table OR to the field with the IDs of person in the table of actions.
What will perform better? Are there advantages to use the one or other way? Some hints or a discussion about this will help me to better understand the cases when what is used better.