Exercise: More subkeys You are given the following table, with data, that identifies works of "classical" music that are in a CD or MP3 library. Draw the relation scheme for a lossless join decomposition of this table. You may assume that composer names are unique Compositions nationalit composer Beethoven Beethoven Brahms Symphony #9 Violin Concerto Violin Concerto Symphony #9 Clarinet Concerto Mozart, W.A Symphony #9 German German German Shostakovich Russian German 1770 1770 1841 1906 1756 1841 Dvorak Czech First, look one-by-one at each attribute If I know the value of "title", what (if anything) else do l know? composer? nationality? year of birth? Try it the other way: What other attribute(s) will tell me the value of title? composer? nationality? year of birth? title and composer? nationality and year of birth? all four attributes in the table? Is there a candidate key for the whole table? If so, what is it? Is there a subkey? Is so, what is it and why? Now draw the revised relation scheme Exercise: More subkeys You are given the following table, with data, that identifies works of "classical" music that are in a CD or MP3 library. Draw the relation scheme for a lossless join decomposition of this table. You may assume that composer names are unique Compositions nationalit composer Beethoven Beethoven Brahms Symphony #9 Violin Concerto Violin Concerto Symphony #9 Clarinet Concerto Mozart, W.A Symphony #9 German German German Shostakovich Russian German 1770 1770 1841 1906 1756 1841 Dvorak Czech First, look one-by-one at each attribute If I know the value of "title", what (if anything) else do l know? composer? nationality? year of birth? Try it the other way: What other attribute(s) will tell me the value of title? composer? nationality? year of birth? title and composer? nationality and year of birth? all four attributes in the table? Is there a candidate key for the whole table? If so, what is it? Is there a subkey? Is so, what is it and why? Now draw the revised relation scheme