Why are recursive relationships bad?
A recursive relationship (one where a table relates to itself) is bad when it is a hard relationship (i.e. neither side is a “may” both are “must”) as this can result in it not being possible to put in a top or perhaps a bottom of the table (for example in the EMPLOYEE table you couldn?t put in the PRESIDENT of the company because he has no boss, or the junior janitor because he has no subordinates). These type of relationships are usually resolved by adding a small intersection entity. 11. What does a hard one-to-one relationship mean (one where the relationship on both ends is “must”) Expected answer: This means the two entities should probably be made into one entity. 12.
