Bissoy.com
Doctors Medicines MCQs Q&A

Consider the following statements regarding database normal forms: 1. Any relation with two attributes is BCNF. 2. Lossless, dependency - preserving decomposition into BCNF is always possible. 3. Lossless, dependency - preserving decomposition into 3NF is always possible. 4. BCNF is stricter than 3NF. Which of the above statements are correct?

Consider the following statements regarding database normal forms: 1. Any relation with two attributes is BCNF. 2. Lossless, dependency - preserving decomposition into BCNF is always possible. 3. Lossless, dependency - preserving decomposition into 3NF is always possible. 4. BCNF is stricter than 3NF. Which of the above statements are correct? Correct Answer 1, 3 and 4

Statement 1: Correct

Any relation with two attributes will always in BCNF

Example:

Relation R = {x, y} non trivial FD’s of this relation is x - > y and y - > x and these both FD’s are in BCNF so this statement is true.

Statement 2: Incorrect

 It is not always possible to decompose a table in BCNF and preserve FD’s and lossless decomposition will always be possible in BCNF.

Example:

XY - > Z and Z - > Y cannot be decomposed in BCNF

Statement 3: Correct

Lossless, dependency - preserving decomposition into 3NF is always possible this statement is true.

Statement 4: correct

BCNF is stricter form of normalization than 3NF because it eliminates the second condition of 3NF.

Hence option 2 is the correct answer.

Related Questions

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?
R (A,B,C,D) is a relation. Which of the following does not have a lossless join dependency preserving BCNF decomposition?
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: 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: Non-trivial functional dependencies: rollno, courseid → email email → rollno Schema III: Non-trivial functional dependencies: rollno, courseid → marks, grade marks → grade Schema IV: Non-trivial functional dependencies: rollno, courseid → credit courseid → credit Which one of the relational schemas above is in 3NF but not in BCNF?
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?
Consider the following graphs. The curves in the graphs indicate different age groups in the populations of two countries A and B over a period of few decades: With reference to the above graphs, which of the following are the most logical and rotational inferences that can be made? 1. Over the last two and a half decades, the dependency ratio for country B has decreased. 2. By the end of the next two and a half decades, the dependency ratio of country A and be much less than that of country B. 3. In the next two decades, the work-force relative to its total population will increase in country B as compared to country A. Select the correct answer using the code given below.
Which of the following statements are correct with regard to the 'truth and validity' in logical reasoning. Select the correct code from the below: (a) Truth and falsity are attributes of individual propositions. (b) Validity and invalidity are attributes of individual propositions. (c) Truth and falsity are attributes of arguments. (d) Validity and invalidity are attributes of arguments. Code:
Consider the relation R(P, Q, S, T, X, Y, Z, W) with the following functional dependencies. PQ → X; P → YX; Q → Y; Y → ZW Consider the decomposition of the relation R into the constituent relations according to the following two decomposition schemes. D1 : R = [(P, Q, S, T); (P, T, X); (Q, Y); (Y, Z, W)] D2 : R = [(P, Q, S); (T, X); (Q, Y); (Y, Z, W)] Which one of the following options is correct?
You are the administrator of a SQL Server 2000 computer. The server contains a database named FinanceData that is used by a client/server application. Each employee has a SQL Server login that the application uses to access the server.Your company hires a new employee named Andrew. You create a SQL Server login named Andrew. You also create a database user named Andrew in the database and grant the database user full permissions in the database.Whenever Andrew runs the client/server application, he receives the following error message: "Invalid object name." Andrew also reports that he cannot access the database by using the application.You need to ensure that Andrew can use the application. Which Transact-SQL statement should you execute?
Which of the following normal form(s) is/are based on the functional dependencies among the attributes of a relation? A. 1NF B. 2NF C. 3NF D. 4 NF
The following are the conditions for selecting list of a suitable candidates to be called for interview after the written test for the recruitment is conducted/organized for management - level persons for a multi - national company. For providing accounting services and sales the candidate must (a) be holding a graduation in basic science with 65% or above or B.E. degree with 55% and above marks (b) have passed the written test with 70% or above marks (c) the age must be in the group 25 to 30 years as on 1/4/18 (d) have experience in an accounting firms for three years and diploma in accounting with 60% or above marks (e)  be presently drawing CTC of 6 Lakhs per annum and above In case the applicant who satisfies all other terms above except 1) at (a) above, then be referred as Junior Accountant 2) at (d) & (e) above then be referred as Trainee - Accountant Satisfying all the above with experience of 5 years then the referred as senior-Accountant Satisfying all the above criteria (a - e) with CA/ICWA/MBA (Finance) then be referred as manager (Accounts) Read all the above information and answer the following question Praveen has done his Masters in physics. He has no experience in accounting neither diploma. He is ready to be on training for accounting after joining. For which position he may be referred