I'm wondering if there is any tip or trick how to find ALL candidate
keys (CK) for a relation and its FDs, w/o using kind of "brute force"
mechanism and trying whether a certain attribute (or composites of
attributes) is CK?
Eg, if there is a relation R=ABCDEFG with following dependencies:
F={AB-->CD, DE-->AB, AC-->F, BF-->EG, E-->C, G-->H, H-->BF}
I found {A,B}, {A,G}, [A,H}, {D,E}, {D,G}, {D,H}, and {B,D,F} as CKs.
I used brute force taktic to get them, but it took me quite a while -
and if I don't want to go through all possibilities of composed
attributes of R, I'm not even sure whether this list is exhaustive (to
my knowledge...).
Sure, finding eg CK {A,B} eliminates other possibilities containing A
and B. Still, it just seems not to be the best way. Is there any
other?
