Which of the following is NOT a superkey in a relational schema with attributes V, W, X, Y, Z and primary key VY?

Which of the following is TRUE?

Which one of the following statements if FALSE?

Let the set of functional dependencies F = {QR → S, R → P, S → Q} hold on a relation schema X = (PQRS). X is not in BCNF. Suppose X is decomposed into two schemas Y and Z, where Y = (PR) and Z = (QRS).

Consider the two statements given below.

• I. Both Y and Z are in BCNF

II. Decomposition of X into Y and Z is dependency preserving and lossless

Which of the above statements is/are correct?

Consider the following four relational schemas. For each schema, all non-trivial functional dependencies are listed. The underlined attributes are the respective primary keys.

Schema I: Registration(rollno, courses)
          Field ‘courses’ is a set-valued attribute containing the set of 
          courses a student has registered for.
          Non-trivial functional dependency
          rollno → courses

Schema II: Registration (rollno, coursid, email)
          Non-trivial functional dependencies:
          rollno, courseid → email
          email → rollno
 	
Schema III: Registration (rollno, courseid, marks, grade)
          Non-trivial functional dependencies:
          rollno, courseid, → marks, grade
          marks → grade
 	
Schema IV: Registration (rollno, courseid, credit)
          Non-trivial functional dependencies:
          rollno, courseid → credit
          courseid → credit

Which one of the relational schemas above is in 3NF but not in BCNF?

Which one of the following statements about normal forms is FALSE?

Consider the following functional dependencies in a database:

  Data_of_Birth → Age
  Age → Eligibility
  Name → Roll_number
  Roll_number → Name
  Course_number → Course_name
  Course_number → Instructor
  (Roll_number, Course_number) → Grade 

The relation (Roll_number, Name, Date_of_birth, Age) is:

Relation R with an associated set of functional dependencies, F, is decomposed into BCNF. The redundancy (arising out of functional dependencies) in the resulting set of relations is

Relation R is decomposed using a set of functional dependencies, F, and relation S is decomposed using another set of functional dependencies, G. One decomposition is definitely BCNF, the other is definitely 3NF, but it is not known which is which. To make a quaranteed identification, which one of the following tests should be used on the decompositions? (Assume that the closures of F and G are available).

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?

Relation R has eight attributes ABCDEFGH . Fields of R contain only atomic values.

F = {CH→G, A→BC, B→CFG, E→A, F→EG}, is a set of functional dependencies (FDs) so that F⁺ is exactly the set of FDs that hold for R.

How many candidate keys does the relation R have?

Relation R has eight attributes ABCDEFGH . Fields of R contain only atomic values.

F = {CH→G, A→BC, B→CFG, E→A, F→EG}, is a set of functional dependencies (FDs) so that F⁺ is exactly the set of FDs that hold for R.

The relation R is

For relation R = (L, M, N , O, P), the following dependencies hold:

   M → O NO → P P → L and L → MN 

R is decomposed into R₁ = (L, M, N , P) and R₂ = (M, O).

(a) Is the above decomposition a lossless-join decomposition? Explain.
(b) Is the above decomposition dependency-preserving? If not, list all the dependencies that are not preserved.
(c) What is the highest normal form satisfied by the above decomposition?

R(A,B,C,D) is a relation. Which of the following does not have a lossless join, dependency preserving BCNF decomposition?

Consider the schema R = (S T U V) and the dependencies S → T, T → U, U → V and V → S. Let R = (R1 and R2) be a decomposition such that R1 ∩ R2 ≠ ∅ . The decomposition is

Which normal form is considered adequate for normal relational database design?

For a database relation R(a,b,c,d), where the domains a, b, c, d include only atomic values, only the following functional dependencies and those that can be inferred from them hold:

   a → c 
   b → d  

This relation is

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)

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??

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?

The relation scheme Student Performance (name, courseNo, rollNo, grade) has the following functional dependencies:

   name, courseNo → grade
   rollNo, courseNo → grade
               name → rollNo
             rollNo → name 

The highest normal form of this relation scheme is

Consider a relational table R that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?