I cant seem to understand this process, I have F =
{ab} -> {cde}
{d} -> {abce}
{a} -> {e}
The keys would be: {a,b} and {d}.
How would I prove this is in 2nf or not?
I cant seem to understand this process, I have F = {ab} -> {cde}
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I cant seem to understand this process, I have F =
{ab} -> {cde}
{d} -> {abce}
{a} -> {e}
The keys would be: {a,b} and {d}.
How would I prove this is in 2nf or not?
Well, based solely on those functional dependencies, {e} is not a candidate key. You might want to do that part over.
Loosely speaking, for a relation to be in 2NF, it must
A partial-key dependency means at least one non-prime attribute is dependent on only part of a candidate key. So if you can prove that just one non-prime attribute is dependent only on {a}, or that just one non-prime attribute is dependent only on {b}, then you’ve proven that R{abcde} is not in 2NF.
Since it’s homework, you’ll want to find the relevant sections in your textbook, and word your answers in line with the text. (Your text probably doesn’t use the term partial-key dependency, and it might prefer superkey to candidate key.)