CSC 4402 20091109

CSC 4402 20091109 - All binary relations are in BCNF(just...

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CSC 4402 11/9/2009 Page 1 of 1 Homework 6 Question #4 R(ABCDEG) F = { AB CD, BCD E, B C, E B } F’ = { AB C, BCD E, B C, E B, AB D } From here we can change AB C to B C (which is a duplicate and one can be removed), and BCD E can be simplified to BD E. This leaves: F min = { AB D, BD E, B C, E B } Because G is not in any FD, G must be in any candidate key of R. AB + = ABDEC We start with B C because C does not appear in the left side of the remaining FDs. See Figure 1 for rest of solution.
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Unformatted text preview: All binary relations are in BCNF (just an FYI). Part B – Not possible to get a BCNF decomposition which is both LLJ and fd-preserving. Homework 6 Question #5 Do an attribute closure on candidate key to see if it contains all the keys of the original relation. Similar example R(ABC); F = { AB C, A B, A C, B C } ( F is not minimal – duh!) F min = { A B, B C } Part 6 Chapter 15 Make sure you know the ACID properties and can explain each of them....
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This note was uploaded on 01/25/2010 for the course CSC 4402 taught by Professor Staff during the Fall '08 term at LSU.

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