Databases question
Consider the following relation that stores information about
students living in dormitories at a college:
a. Using these assumptions and stating any others you need to make, list all the non-trivial functional dependencies for this relation
b. What are the candidate keys for this relation? Identify the primary keys
c. Is this relation in third normal form? if not find a 3NF lossless join decomposition of College that preserves dependencies.
d.Is the relation or the resulting set of the relations in BCNF? if not find a lossless join decomposition that in BCNF. identify any functional dependencies that are not preserved.
Databases question Consider the following relation that stores information about students living in dormitories at a...
Language: SQL - Normalization and Functional Dependencies Part 4 Normalization and Functional Dependencies Consider the following relation R(A, B, C, D)and functional dependencies F that hold over this relation. F=D → C, A B,A-C Question 4.1 (3 Points) Determine all candidate keys of R Question 4.2 (4 Points) Compute the attribute cover of X-(C, B) according to F Question 43 (5 Points) Compute the canonical cover of F.Show each step of the generation according to the algorithm shown in class....
Consider a relation R(A,B,C,D,E) with the following functional dependencies: 8. AB C BCD CDE DEA (a) Specify all candidate keys for R. (b) Which of the given functional dependencies are Boyce-Codd Normal Form (BCNF) violations'? (c) Give a decomposition of R into BCNF based on the given functional dependencies. (d) Give a different decomposition of R into BCNF based on the given functional dependencies. (e) Give a decomposition of R into 3NF based on the given functional dependencies. Consider a...
Consider a relation R(A,B,C,D,E) with the following functional dependencies: 8. AB C BCD CDE DEA (a) Specify all candidate keys for R. (b) Which of the given functional dependencies are Boyce-Codd Normal Form (BCNF) violations'? (c) Give a decomposition of R into BCNF based on the given functional dependencies. (d) Give a different decomposition of R into BCNF based on the given functional dependencies. (e) Give a decomposition of R into 3NF based on the given functional dependencies.
Which of the following statements is CORRECT? (1 Point) Select one: O Every relation that is in 3NF have no redundancy. A relation that is in BCNF could have some redundancy. Every relation that is in 3NF is also in BCNF. For Every relation that is not in BCNF, we can always find a lossless-join and dependency-preserving decomposition of the relation into BCNF relations. All of the above. O None of the above
Which of the following statements is CORRECT? (1 Point) Select one: Every relation that is in 3NF have no redundancy. O A relation that is in BCNF could have some redundancy. Every relation that is in 3NF is also in BCNF. For Every relation that is not in BCNF, we can always find a lossless-join and dependency-preserving decomposition of the relation into BCNE relations All of the above. None of the above.
Which of the following statements is CORRECT? (1 Point) Select one: O Every relation that is in 3NF have no redundancy. O A relation that is in BCNF could have some redundancy. o Every relation that is in 3NF is also in BCNF. For Every relation that is not in BCNF, we can always find a lossless-join and dependency-preserving decomposition of the relation into BCNF relations All of the above. None of the above
Normalisation Consider the following relation schema about project meetings: PMG(projID, title, type, manager, jobID, start-date, end-date, contractor, contractNo) Some notes on the semantics of attributes are as follows: • Each project has a unique project ID (projID) and also has a title, type and manager. Each manager has a specialty project type. • A project often contracts jobs to contractors with start-date and end-date. Contracts are identified by contract numbers (contractNo), but contract details are out of the scope of...
Dependency Very Good dependency (key dependency) : XA where Table Very good If all dependencies in a table are '"very good", the table is in BCNF X is a candidate key Good Good dependency: X-> A where If all dependencies in a table are "very good" or "good", the table is in 3NF X is not a candidate key X is a part of a candidate key A is prime attribute Bad Bad dependency (Transitive Dependency): X A where If...
Consider the relation concerning refrigerators Ref (Model#, Year, Price, Manuf_Plant, Color) and the following set of functional dependencies: Model# → Manuf_Plant Model#, Year → Price Manuf_Plant → Color (i) Evaluate each of the following as a candidate key for Ref, giving reasons why it can or cannot be a candidate key: {Model#}, {Model#, Year}, {Model#, Color}. (ii) Based on the result of (i) above, determine whether the relation Ref is in 3NF and in BCNF. You should justify your answers....
[1] [30 points] Consider the relation R City, Street, Zip Code), where a tuple (c, s, z) is in R only if city c has a building with street s, and z is the zipcode for that address in that city. It is assumed that the nontrivial functional dependencies are: Street → Zip Code ZipCode → City City, [a] [b] [C] [d] [e] Determine all possible keys for R. Indicate all possible BCNF and 3NF violations. Decompose R as necessary...