41. | Consider the FDs given in above question. The relation R is |
Discuss |
Answer: (a).in 1NF, but not in 2NF
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42. | Which of the following is TRUE? |
Discuss |
Answer: (c).Every relation in BCNF is also in 3NF
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43. | Consider a relational table with a single record for each registered student with the following attributes. 1. Registration_Num: Unique registration number of each registered student 2. UID: Unique identity number, unique at the national level for each citizen 3. BankAccount_Num: Unique account number at the bank. A student can have multiple accounts or join accounts. This attribute stores the primary account number. 4. Name: Name of the student 5. Hostel_Room: Room number of the hostel Which one of the following option is INCORRECT? |
Discuss |
Answer: (a).BankAccount_Num is candidate key
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44. | Consider a relational table with a single record for each registered student with the following attributes. 1. Registration_Num: Unique registration number of each registered student 2. UID: Unique identity number, unique at the national level for each citizen 3. BankAccount_Num: Unique account number at the bank. A student can have multiple accounts or join accounts. This attribute stores the primary account number. 4. Name: Name of the student 5. Hostel_Room: Room number of the hostel Which one of the following option is INCORRECT? |
Discuss |
Answer: (a).BankAccount_Num is candidate key
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45. | Consider the following relational schema: Suppliers(sid:integer, sname:string, city:string, street:string) Parts(pid:integer, pname:string, color:string) Catalog(sid:integer, pid:integer, cost:real) (sid,pid are primary keys) Assume that, in the suppliers relation above, each supplier and each street within a city has a unique name, and (sname, city) forms a candidate key. No other functional dependencies are implied other than those implied by primary and candidate keys. Which one of the following is TRUE about the above schema? |
Discuss |
Answer: (a).The schema is in BCNF
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46. | Consider the following relational schemes for a library database: Book (Title, Author, Catalog_no, Publisher, Year, Price) Collection (Title, Author, Catalog_no) with in the following functional dependencies: I. Title Author --> Catalog_no II. Catalog_no --> Title, Author, Publisher, Year III. Publisher Title Year --> Price Assume {Author, Title} is the key for both schemes. Which of the following statements is true? |
Discuss |
Answer: (c).Book is in 2NF and Collection is in 3NF
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47. | Consider the relation scheme R = {E, F, G, H, I, J, K, L, M, M} and the set of functional dependencies {{E, F} -> {G}, {F} -> {I, J}, {E, H} -> {K, L}, K -> {M}, L -> {N} on R. What is the key for R? |
Discuss |
Answer: (b).{E, F, H}
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48. | Given the following two statements: S1: Every table with two single-valued attributes is in 1NF, 2NF, 3NF and BCNF. S2: AB->C, D->E, E->C is a minimal cover for the set of functional dependencies AB->C, D->E, AB->E, E->C. Which one of the following is CORRECT? |
Discuss |
Answer: (a).S1 is TRUE and S2 is FALSE
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49. | The maximum number of superkeys for the relation schema R(E,F,G,H) with E as the key is |
Discuss |
Answer: (d).8
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50. | Which one of the following statements about normal forms is FALSE? |
Discuss |
Answer: (c).Lossless, dependency-preserving decomposition into BCNF is always possible
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