I want to model the following scenario for an online marketing application:
Users can create mailings. The list of recipients can be uploaded as spreadsheets with arbitrary columns (each row is a recipient). I expect the following maximum quantities the DB will contain:
I see basically two approaches to store the recipients:
A) A single table with a fixed number of generic columns. If the spreadsheet has less columns than the table, the values will be null.
B) Two tables, one for the recipients and one for the values:
One more option is to use arrays (and single table).