To get the minimal cover, you have to make two steps. To demonstrate, I’ll first split the dependencies into multiple (only one attribute on the right side) to make it more clean: A -> B ABCD -> E EF -> G EF -> H ACDF -> E ACDF -> G The following steps must be … Read more
Actually, it’s a “functional dependency”. In this case that means that m uniquely identifies w — the type m determines the type w. (This may be a better link.)
A candidate key is a minimal superkey. In other words, there are no superflous attributes in the key. The first step to finding a candidate key, is to find all the superkeys. For those unfamiliar, a super key is a set of attributes whose closure is the set of all atributes. In other words, a … Read more
“Illegal type synonym family application in instance” with functional dependency
Take an FD, e.g. AB→C Augment until all attributes are mentioned, e.g. ABDEFG → CDEFG (note that this is equivalent to ABDEFG → ABCDEFG because it is trivially true that A->A and B->B). This tells you that ABDEFG is a superkey. Check the other FDs in which the LHS is a subset of your superkey, … Read more