DBMS: Solved 554 DBMS Questions and answers section with explanation for various online exam preparation, various interviews, Logical Reasoning Category online test. Category Questions section with detailed description, explanation will help you to master the topic.
1. Select name, course_id from instructor, teaches where instructor_ID= teaches_ID; This Query can be replaced by which one of the following ?
Correct Ans:Select name, course_id from instructor natural join teaches;
2. What will be the number of columns and rows respectively obtained for the operation, AB, if A B are Base union compatible and all the rows of a are common to B? Assume A has 4 columns and 10 rows; and B has 4 columns and 15 rows
7. Consider the following transactions with data items P and Q initialized to zero: T1: read (P) ; read (Q) ; if P = 0 then Q : = Q + 1 ; write (Q) ; T2: read (Q) ; read (P) ; if Q = 0 then P : = P + 1 ; write (P) ; Any non-serial interleaving of T1 and T2 for concurrent execution leads to
Correct Ans:A schedule that is not conflict serializable
8. Which of the following statements are TRUE about an SQL query?
P: An SQL query can contain a HAVING clause even if it does not a GROUP BY clause Q: An SQL query can contain a HAVING clause only if it has a GROUP BY clause R: All attributes used in the GROUP BY clause must appear in the SELECT clause S: Not all attributes used in the GROUP BY clause need to appear in the SELECT clause
9. In SQL, relations can contain null values, and comparisons with null values are treated as unknown. Suppose all comparisons with a null value are treated as false. Which of the following pairs is not equivalent?
12. Let E1 and E2 be two entities in an E/R diagram with simple single-valued attributes. R1 and R2 are two relationships between E1 and E2, where R1 is one-to-many and R2 is many-to-many. RI and R2 do not have any attributes of their own. What is the minimum number of tables required to represent this situation in the relational model?
14. The following functional dependencies hold for relation R(A, B, C) and S(B, D, E) B —> A, A —> C , the relation R contains 200 tuples and relation S contains 100 tuples. What is maximum number of tuples possibles in natural join R and S ?
16. THE RELATIONAL SCHEMA STUDENT PERFORMANCE(NAME, COURSENO, ROLLNO, GRADE) HAS THE FOLLOWING FUNCTIONAL INDEPENDENCE NAME, COURSENO -> GRADE ROLLNO,COURSENO -> GRADE NAME-> ROLLNO ROLLNO->NAME THE HIGHEST NORMAL FORM OF THIS RELATION SCHEME IS
1 NF says that the attributes should not be repeated. Here we can see that the attributes are not repeated. Condition is satisfied hence the relation schema is in 1 NF, 2nf says there should not be any partial dependency. Here it can be seen that there is no partial dependency. Condition is satisfied and hence the relation is in 2NF. Last two lines of code show transitive dependency hence it is in 3nf
19. In SQL relations can contain null values, and comparisons with null values are treated as unknown. Suppose all comparisons with a null value are treated as false. Which of the following pairs is not equivalent ?
20. The order of an internal node in a B+ tree index is the maximum number of children it can have . Suppose that a child pointer takes 6 bytes, the search field value takes 14 bytes, and the block size is 512 bytes. What is the order of the internal node ?
Are you seeking for good platform for practicing DBMS questions in online. This is the right place. The time you spent in Fresherslive will be the most beneficial one for you.
Online Test on DBMS @ Fresherslive
This page provides important questions on DBMS along with correct answers and clear explanation, which will be very useful for various Interviews, Competitive examinations and Entrance tests. Here, Most of the DBMS questions are framed with Latest concepts, so that you may get updated through these DBMS Online tests. DBMS Online Test questions are granted from basic level to complex level.
Why To Practice DBMS Test questions Online @ Fresherslive?
DBMS questions are delivered with accurate answer. For solving each and every question, very lucid explanations are provided with diagrams wherever necessary.
Practice in advance of similar questions on DBMS may improve your performance in the real Exams and Interview.
Time Management for answering the DBMS questions quickly is foremost important for success in Competitive Exams and Placement Interviews.
Through Fresherslive DBMS questions and answers, you can acquire all the essential idea to solve any difficult questions on DBMS in short time and also in short cut method.
Winners are those who can use the simplest method for solving a question. So that they have enough time for solving all the questions in examination, correctly without any tense. Fresherslive provides most simplest methods to answer any tough questions. Practise through Fresherslive test series to ensure success in all competitive exams, entrance exams and placement tests.
Why Fresherslive For DBMS Online Test Preparation?
Most of the job seekers finding it hard to clear DBMS test or get stuck on any particular question, our DBMS test sections will help you to success in Exams as well as Interviews. To acquire clear understanding of DBMS, exercise these advanced DBMS questions with answers.
You're Welcome to use the Fresherslive Online Test at any time you want. Start your beginning, of anything you want by using our sample DBMS Online Test and create yourself a successful one. Fresherslive provides you a new opportunity to improve yourself. Take it and make use of it to the fullest. GOODLUCK for Your Bright Future.
FreshersLive - No.1 Job site in India. Here you can find latest 2020 government as well as private job recruitment notifications for different posts vacancies in India. Get top company jobs for both fresher and experienced. Job Seekers can get useful interview tips, resume services & interview Question and answer. Practice online test free which is helpful for interview preparation. Register with us to get latest employment news/rojgar samachar notifications. Also get latest free govt and other sarkari naukri job alerts daily through E-mail.