Hi everyone,
what do the Bachman type arrows (bullet instead of crow's foot as source) mean in the relational model?
I am not talking about the logical model, where you can switch between Bachman and Barker notation. I have a relational model, obtained by reverse engineering from a database,
and it contains a mixture of crow's foot type foreign key arrows with bullet type arrows. I can't find out what makes the difference.
Can anyone help me?