Say I have want to create a database for expenses.
I will have a table for holding Person details, and a table for holding Expense details.
Then there will be two many-to-many relationships between the Person and the Expenses tables. Person Can pay an expense, and a Person can use an expense.
What is considered better? Having one relationship table to hold both "paid for" / "used by" fields. Or two have two separate tables containing each of these fields?
Two parallel tables seems more correct, but I could also see it making the SQL more complex. Is there any compelling reason to use one design over the other?