Description : Consider the relations R(A,B) and S(B,C) and the following four relational algebra queries over R and S: I. πA,B(R⋈S) II. R⋈πB(S) III. R∩(πA(R) Χ πB(S)) IV. πA,R.B(R Χ S) where R.B refers to ... IV are the same query. (C) I, II and IV are the same query. (D) I, III and III are the same query.
Last Answer : (D) I, III and III are the same query.
Description : The relational model is based on the concept that data is organized and stored in two-dimensional tables called ………………………A) Fields B) Records C) Relations D) Keys
Last Answer : C) Relations
Description : A relational database developer refers to a record as (A) a criteria. (B) a relation. (C) a tuple. (D) an attribute.
Last Answer : C) a tuple
Description : In a relational database model, NULL values can be used for all but which one of the following? (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL. (B) To ... D) To fill a column in a tuple when that column does not really exist for that particular tuple.
Last Answer : (A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL.
Description : Consider the following statements regarding relational database model: (a) NULL values can be used to opt a tuple out of enforcement of a foreign key. (b) Suppose that table T has only one candidate key. If Q is in 3NF, then it is ... true. (C) (b) and (c) are true. (D) (a), (b) and (c) are true.
Last Answer : (D) (a), (b) and (c) are true.
Description : A relational database management (RDBM) package manages datain morethan one file at once. How does itorganizethese file? As A. tables B. relations C. tuple D. both (a)and (b) E. None of the above
Last Answer : both (a)and (b)
Description : A top-to-bottom relationship among the items in a database is established by a A) Hierarchical schema B) Network schema C) Relational Schema D) All of the above
Last Answer : A) Hierarchical schema
Description : Relational database schema normalization is NOT for: (A) reducing the number of joins required to satisfy a query. (B) eliminating uncontrolled redundancy of data stored in the database. (C) ... could otherwise occur with inserts and deletes. (D) ensuring that functional dependencies are enforced.
Last Answer : reducing the number of joins required to satisfy a query.
Description : If D1, D2,…. Dn are domains in a relational model, then the relation is a table, which is a subset of (A) D1+D2+…. +Dn (B) D1x D2x… xDn (C) D1U D2U….UDn (D) D1- D2-….-Dn
Last Answer : (B) D1x D2x… xDn
Description : Consider the following ORACLE relations: R(A,B,C) = {, , , , ,< 3,1,4>} S(B,C,D) = {, , , , } Consider the following two SQL queries SQ1 and SQ2: SQ1: SELECT R.B, AVG(S.B) FROM R, S WHERE R.A = S.C AND S.D ... tuples returned by SQ2 then (A) M=4, N=2 (B) M=5, N=3 (C) M=2, N=2 (D) M=3, N=3
Last Answer : (A) M=4, N=2
Description : In a relational model, relations are termed as (A) Tuples. (B) Attributes (C) Tables. (D) Rows.
Last Answer : (C) Tables
Description : In a relational database, this is a data structure that organizes the information about a single topic into rows and columns. 1) Block 2) Record 3) Tuple 4) Table 5) Command line interface
Last Answer : Answer :4
Description : Goals for the design of thelogical schema include A. avoiding data inconsistency B. being ableto construct queries easily C. being ableto access data efficiently D. All of theabove E. None of the above
Last Answer : All of theabove
Description : How does Tuple-oriented relational calculus differ from domain-oriented relational calculus?
Last Answer : The tuple-oriented calculus uses a tuple variables i.e., variable whose only permitted values are tuples of that relation. E.g. QUEL The domain-oriented calculus has domain variables i.e., variables that range over the underlying domains instead of over relation. E.g. ILL, DEDUCE.
Description : Which of the following describes a relational database? 1) It provides a relationship between integers 2) It consists of separate tables or related data 3) It retrieves data related to its queries 4) It provides a relationship between floats
Last Answer : 2) It consists of separate tables or related data
Description : A set of possible data values is called (A) attribute. (B) degree. (C) tuple. (D) domain.
Last Answer : D) domain.
Description : A .................. normal form normalization will be needed where all attributes in a relation tuple are not functionally dependent only on the key attribute. A) First B) Second C) Third D) Fourth
Last Answer : C) Third
Description : The RDBMS terminology for a row is (A) tuple. (B) relation. (C) attribute. (D) degree.
Last Answer : (A) tuple
Description : Is the following piece of code valid? >>> a=(1,2,3,4) >>> del a a) No because tuple is immutable b) Yes, first element in the tuple is deleted c) Yes, the entire tuple is deleted
Last Answer : c) Yes, the entire tuple is deleted
Description : What is the output of the following code? >>> a=(1,2,3,4) >>> del(a[2]) a) Now, a=(1,2,4) b) Now, a=(1,3,4) c) Now a=(3,4) d) Error as tuple is immutable
Last Answer : d) Error as tuple is immutable
Description : If a=(1,2,3,4), a[1:-1] is a) Error, tuple slicing doesn’t exist b) [2,3]. c) (2,3,4) d) (2,3)
Last Answer : d) (2,3)
Description : What is the data type of (1)? a) Tuple b) Integer c) List d) Both tuple and integer
Last Answer : b) Integer
Description : Which of the following is a Python tuple? a) [1, 2, 3]. b) (1, 2, 3) c) {1, 2, 3} d) {}
Last Answer : b) (1, 2, 3)
Description : A logical schema A) is the entire database B) is a standard way of organizing information into accessible parts. C) Describes how data is actually stored on disk. D) All of the above
Last Answer : B) is a standard way of organizing information into accessible parts.
Description : Which of the following statements is TRUE? D1: The decomposition of the schema R(A,B,C) into R1(A,B) and R2(A,C) is always lossless. D2: The decomposition of the schema R(A,B,C,D,E) having AD→B, C→DE, B→AE, AE→C ... ,D,E) is lossless. (A) Both D1 and D2 (B) Neither D1 and D2 (C) Only D1 (D) Only D2
Last Answer : (D) Only D2
Description : Consider a schema R(MNPQ) and functional dependencies M→N, P→Q. Then the decomposition of R into R1(MN) and R2(PQ) is ............. (1) Dependency preserving but not lossless ... and lossless join (3) Lossless join but not dependency preserving (4) Neither dependency preserving nor lossless join.
Last Answer : Answer: 1
Description : .......... is a special type of programming language used to provide instructions to the monitor simple batch processing schema. A) Job control language (JCL) B) Processing control language (PCL) C) Batch control language (BCL)
Last Answer : A) Job control language (JCL)
Description : ……………. Allows definitions and query language statements to be entered; query results are formatted and displayed. A) Schema Processor B) Query Processor C) Terminal Interface D) None of the above
Last Answer : C) Terminal Interface
Description : Anything that affects the database schema is a part of A) DML B) DCL C) DDL D) All of the above
Last Answer : D) All of the above
Description : ………..defines the structure of a relation which consists of a fixed set of attribute-domain pairs. A) Instance B) Schema c) Program D) Super Key
Last Answer : B) Schema
Description : The database schema is written in (A) HLL (B) DML (C) DDL (D) DCL
Last Answer : (C) DDL
Description : A Network Schema (A) restricts to one to many relationship (B) permits many to many relationship (C) stores Data in a Database (D) stores Data in a Relation
Last Answer : (B) permits many to many relationship
Description : Consider the following two commands C1 and C2 on the relation R from an SQL database: C1: drop table R; C2: delete from R; Which of the following statements is TRUE? I. Both C1 and C2 delete the schema for R. II. C2 ... R. (A) I only (B) I and II only (C) II and III only (D) I, II and III
Last Answer : (C) II and III only
Description : DBMS provides the facility of accessing data from a database through (A) DDL (B) DML (C) DBA (D) Schema
Last Answer : (B) DML
Description : Preparedstatement Object in JDBC is used to execute ........................... queries. A) executable B) simple C) high level D) parameterized
Last Answer : D) parameterized
Description : Prepared Statement object in JDBC used to execute........... queries. A) Executable B) Simple C) High level D) Parameterized
Last Answer : D) Parameterized
Description : Which of the following is not the function of client? A) Compile queries B) Query optimization C) Receive queries D) Result formatting and presentation
Last Answer : B) Query optimization
Description : Which of the following is/are the Database server functions? i) Data management ii) Transaction management iii) Compile queries iv) Query optimization A) i, ii, and iv only B) i, ii and iii only C) ii, iii and iv only D) All i, ii, iii, and iv
Last Answer : A) i, ii, and iv only
Description : Consider the table Student(stuid, name, course, marks). Which one of the following two queries is correct to find the highest marks student in course 5? Q.1. Select S.stuid From student S Where not exists (select * from student ... ) Q.1 (B) Q.2 (C) Both Q.1 and Q.2 (D) Neither Q.1 nor Q.2
Last Answer : (B) Q.2 Explanation: First query gives stuid of students whose marks are greater than all students taking course 5. Second query gives stuid of students whose marks are greater than any student taking ... comparison is between maximum of marks by any student in course 5. So the answer is option D.
Description : Division operation is ideally suited to handle queries of the type : (A) customers who have no account in any of the branches in Delhi. (B) customers who have an account at all branches in Delhi. ( ... atleast one branch in Delhi. (D) customers who have only joint account in any one branch in Delhi
Last Answer : (B) customers who have an account at all branches in Delhi.
Description : Consider the following three SQL queries (Assume the data in the people table) : (a) Select Name from people where Age>21; (b) Select Name from people where Height>180; (c) Select Name from people where (Age>21) or (Height ... number of rows returned by the SQL query (c) ? (A) 3 (B) 7 (C) 10 (D) 21
Last Answer : (C) 10
Description : Suppose ORACLE relation R(A, B) currently has tuples {(1, 2), (1, 3), (3, 4)} and relation S(B, C) currently has {(2, 5), (4, 6), (7, 8)}. Consider the following two SQL queries SQ1 and SQ2 ... (A) 2 and 6 respectively (B) 6 and 2 respectively (C) 2 and 4 respectively (D) 4 and 2 respectively
Last Answer : (D) 4 and 2 respectively
Description : Consider a database table R with attributes A and B. Which of the following SQL queries is illegal ? (A) SELECT A FROM R; (B) SELECT A, COUNT(*) FROM R; (C) SELECT A, COUNT(*) FROM R GROUP BY A; (D) SELECT A, B, COUNT(*) FROM R GROUP BY A, B;
Last Answer : (B) SELECT A, COUNT(*) FROM R;
Description : For a database relation R(a, b, c, d) where the domains of a, b, c, d include only the atomic values. The functional dependency a → c, b → d holds in the following relation (A) In 1NF not in 2NF (B) In 2NF not in 3NF (C) In 3NF (D) In 1NF
Last Answer : (A) In 1NF not in 2NF
Description : For a database relation R(A,B,C,D) where the domains of A,B,C and D include only atomic values, only the following functional dependencies and those that can be inferred from them are: A→C B→D The ... form but not in third normal form (4) Both in second normal form as well as in third normal form
Last Answer : First normal form but not in second normal form
Description : Which of the following is not a binary operator in relational algebra? A) Join B) Semi-Join C) Assignment D) Project
Last Answer : D) Project
Description : Which of the following is not a logical database structure? A) Chain B) Network C) Tree D) Relational
Last Answer : A) Chain
Description : Cartesian product in relational algebra is (A) a Unary operator. (B) a Binary operator. (C) a Ternary operator. (D) not defined.
Last Answer : (B) a Binary operator.
Description : In the relational modes, cardinality is termed as: (A) Number of tuples. (B) Number of attributes. (C) Number of tables. (D) Number of constraints
Last Answer : (A) Number of tuples
Description : The “PROJECT” operator of a relational algebra creates a new table that has always (A) More columns than columns in original table (B) More rows than original table (C) Same number of rows as the original table (D) Same number of columns as the original table
Last Answer : (C) Same number of rows as the original table