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>180); If the SQL queries (a) and (b) above, return 10 rows and 7 rows in the result set respectively, then what is one possible number of rows returned by the SQL query (c) ? (A) 3 (B) 7 (C) 10 (D) 21

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>180); If the SQL queries (a) and (b) above, return 10 rows and 7 rows in the result set respectively, then what is one possible number of rows returned by the SQL query (c) ? (A) 3 (B) 7 (C) 10 (D) 21
by

1 Answer

Answer :

(C) 10
by

Related questions

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 : SQ1 : Select * From R Full Join S On R.B=S.B; SQ2 : Select * From R Inner Join S On R.B=S.B; The numbers of tuples in the result of the SQL query SQ1 and the SQL query SQ2 are given by : (A) 2 and 6 respectively (B) 6 and 2 respectively (C) 2 and 4 respectively (D) 4 and 2 respectively

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

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;

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;

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 the column B in table R. One can determine that: (A) I, III and IV are the same query. (B) II, III and IV are the same query. (C) I, II and IV are the same query. (D) I, III and III are the same query.

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.

Semi-join strategies are techniques for query processing in distributed database system. Which of the following is a semi-join technique? (A) Only the joining attributes are sent from one site to another and then all of the rows are returned. (B) All of the attributes are sent from one site to another and then only the required rows are returned. (C) Only the joining attributes are sent from one site to another and then only the required rows are returned. (D) All of the attributes are sent from one site to another and then only the required rows are returned.

Description : Semi-join strategies are techniques for query processing in distributed database system. Which of the following is a semi-join technique? (A) Only the joining attributes are sent from one site to ... the attributes are sent from one site to another and then only the required rows are returned.

Last Answer : (C) Only the joining attributes are sent from one site to another and then only the required rows are returned.

Which of the following is not the function of client? A) Compile queries B) Query optimization C) Receive queries D) Result formatting and presentation

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

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 e where e course='5' and e marks ≥ s marks) Q.2. Select S.stuid From student S Where s.marks > any (select distinct marks from student S where s.couse = 5) (A) Q.1 (B) Q.2 (C) Both Q.1 and Q.2 (D) Neither Q.1 nor Q.2

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.

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

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

Consider a “CUSTOMERS” database table having a column “CITY” filled with all the names of Indian cities (in capital letters). The SQL statement that finds all cities that have “GAR” somewhere in its name, is: (A) Select *from customers where city=’%GAR%’; (B) Select *from customers where city=’$GAR$’; (C) Select *from customers where city like ‘%GAR%’; (D) Select *from customers where city as ’%GAR’;

Description : Consider a CUSTOMERS database table having a column CITY filled with all the names of Indian cities (in capital letters). The SQL statement that finds all cities that have GAR somewhere in its name, ... *from customers where city like %GAR%'; (D) Select *from customers where city as '%GAR';

Last Answer : Answer: C

Consider the following table Furniture. Write SQL commands for the statements (i) to (viii) and write output for SQL queries (ix) and (x). -Technology

Description : Consider the following table Furniture. Write SQL commands for the statements (i) to (viii) and write output for SQL queries (ix) and (x). -Technology

Last Answer : SQL commands for the given statements (i) to (viii) ;1. SELECT FCODE, NAME. PRICE FROM Furniture WHERE PRICE < 5000;2. SELECT NAME. PRICE FROM Furniture3.4. WHERE NAME LIKE %table% ;5. SELECT DISTINCT WCODE ... ;15.16. Output for SQL queries (ix) and (x)(ix)SUM(PRICE)6500(x)COUNT(DISTINCT PRICE)5

In distributed databases, location transparency allows for database users, programmers and administrators to treat the data as if it is at one location. A SQL query with location transparency needs to specify: (A) Inheritances (B) Fragments (C) Locations (D) Local formats

Description : In distributed databases, location transparency allows for database users, programmers and administrators to treat the data as if it is at one location. A SQL query with location transparency needs to specify: (A) Inheritances (B) Fragments (C) Locations (D) Local formats 

Last Answer : (B) Fragments

Consider the fractional knapsack instance n = 4, (p1, p2, p3, p4) = (10, 10, 12, 18), (w1, w2, w3, w4) = (2, 4, 6, 9) and M = 15. The maximum profit is given by (Assume p and w denotes profit and weight of objects respectively) (A) 40 (B) 38 (C) 32 (D) 30

Description : Consider the fractional knapsack instance n = 4, (p1, p2, p3, p4) = (10, 10, 12, 18), (w1, w2, w3, w4) = (2, 4, 6, 9) and M = 15. The maximum profit is given by (Assume p and w denotes profit and weight of objects respectively) (A) 40 (B) 38 (C) 32 (D) 30

Last Answer : (B) 38

Consider a disk queue with request for input/output to block on cylinders 98, 183, 37, 122, 14, 124, 65, 67 in that order. Assume that disk head is initially positioned at cylinder 53 and moving towards cylinder number 0. The total number of head movements using Shortest Seek Time First (SSTF) and SCAN algorithms are respectively (A) 236 and 252 cylinders (B) 640 and 236 cylinders (C) 235 and 640 cylinders (D) 235 and 252 cylinders

Description : Consider a disk queue with request for input/output to block on cylinders  98, 183, 37, 122, 14, 124, 65, 67  in that order. Assume that disk head is initially positioned at cylinder 53 and moving ... and 252 cylinders (B) 640 and 236 cylinders (C) 235 and 640 cylinders (D) 235 and 252 cylinders

Last Answer : Answer: 236 and 208 cylinders Explanation: SSTF Initial head position =53 The closest queue to initial head position=65 head moves from 53 to 65=12 head moves from 65 to 67=2 head moves from 67 ... 122=24 head moves from 122 to 124=2 head moves from 124 to 183=59 Total head movement=208 

For execution of DELETE SQL query in JDBC, ............. method must be used. A) executeQuery() B) executeDeleteQuery() C) executeUpdate() D) executeDelete()

Description : For execution of DELETE SQL query in JDBC, ............. method must be used. A) executeQuery() B) executeDeleteQuery() C) executeUpdate() D) executeDelete()

Last Answer : C) executeUpdate()

………………… is a full form of SQL. A) Standard query language B) Sequential query language C) Structured query language D) Server side query language

Description : ………………… is a full form of SQL. A) Standard query language B) Sequential query language C) Structured query language D) Server side query language

Last Answer : A) Standard query language

The statement in SQL which allows to change the definition of a table is (A) Alter. (B) Update. (C) Create. (D) select.

Description : The statement in SQL which allows to change the definition of a table is (A) Alter. (B) Update. (C) Create. (D) select

Last Answer : (A) Alter.

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 retains relation R, but deletes all tuples in R. III. C1 deletes not only all tuples of R, but also the schema for R. (A) I only (B) I and II only (C) II and III only (D) I, II and III

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

Consider three CPU intensive processes P1, P2, P3 which require 20, 10 and 30 units of time, arrive at times 1, 3 and 7 respectively. Suppose operating system is implementing Shortest Remaining Time first (preemptive scheduling) algorithm, then .............. context switches are required (suppose context switch at the beginning of Ready queue and at the end of Ready queue are not counted). (A) 3 (B) 2 (C) 4 (D) 5

Description : Consider three CPU intensive processes P1, P2, P3 which require 20, 10 and 30 units of time, arrive at times 1, 3 and 7 respectively. Suppose operating system is implementing Shortest Remaining Time first (preemptive scheduling) ... end of Ready queue are not counted). (A) 3 (B) 2 (C) 4 (D) 5

Last Answer : (A) 3

What is the value returned by the function f given below when n = 100 ? int f(int n) { if (n==0) then return n; else return n + f(n-2); } (A) 2550 (B) 2556 (C) 5220 (D) 5520

Description : What is the value returned by the function f given below when n = 100 ? int f(int n)  { if (n==0) then return n;  else return n + f(n-2);  } (A) 2550 (B) 2556 (C) 5220 (D) 5520

Last Answer : (A) 2550

Consider the following schemas: Branch = (Branch-name, Assets, Branch-city) Customer = (Customer-name, Bank-name, Customer-city) Borrow = (Branch-name, loan-number, customer account-number) Deposit = (Branch-name, Account-number, Customer-name, Balance) Using relational Algebra, the query that finds customers who have balance more than 10,000 is ................. (A) πcustomer-name(σbalance> 10000(Deposit)) (B) σcustomer-name(σbalance> 10000(Deposit)) (C) πcustomer-name(σbalance> 10000(Borrow)) (D) σcustomer-name(σbalance> 10000(Borrow))

Description : Consider the following schemas: Branch = (Branch-name, Assets, Branch-city) Customer = (Customer-name, Bank-name, Customer-city) Borrow = (Branch-name, loan-number, customer account-number) Deposit = ... )) (C) πcustomer-name(σbalance> 10000(Borrow)) (D) σcustomer-name(σbalance> 10000(Borrow))

Last Answer : (A) πcustomer-name(σbalance> 10000(Deposit)) 

Which of the following is true ? I. Implementation of self-join is possible in SQL with table alias. II. Outer-join operation is basic operation in relational algebra. III. Natural join and outer join operations are equivalent. (A) I and II are correct. (B) II and III are correct. (C) Only III is correct. (D) Only I is correct.

Description : Which of the following is true ? I. Implementation of self-join is possible in SQL with table alias. II. Outer-join operation is basic operation in relational algebra. III. Natural join and outer join operations are ... (B) II and III are correct. (C) Only III is correct. (D) Only I is correct.

Last Answer : (D) Only I is correct.

How many rows will the following SQL return

Description : How many rows will the following SQL return

Last Answer : Select * from emp Where rownum < 10; 9 rows.

Consider the reference string 0 1 2 3 0 1 4 0 1 2 3 4 If FIFO page replacement algorithm is used, then the number of page faults with three page frames and four page frames are .......... and ........... respectively. (A) 10, 9 (B) 9, 9 (C) 10, 10 (D) 9, 10

Description : Consider the reference string 0 1 2 3 0 1 4 0 1 2 3 4 If FIFO page replacement algorithm is used, then the number of page faults with three page frames and four page frames are .......... and ........... respectively. (A) 10, 9 (B) 9, 9 (C) 10, 10 (D) 9, 10

Last Answer : (D) 9, 10

Let us assume that you construct ordered tree to represent the compound proposition (~(p˄q))↔(~p˅~q). Then, the prefix expression and post-fix expression determined using this ordered tree are given as ........... and ............. respectively. (A) ↔~˄pq˅ ~~pq, pq˄~p~q~˅↔ (B) ↔~˄pq˅ ~p~q, pq˄~p~q~˅↔ (C) ↔~˄pq˅ ~~pq, pq˄~p~ ~q˅↔ (D) ↔~˄pq˅ ~p~q, pq˄~p~~q˅↔

Description : Let us assume that you construct ordered tree to represent the compound proposition (~(p˄q))↔(~p˅~q). Then, the prefix expression and post-fix expression determined using this ordered tree are given as ........... and .......... ... ~p~q~˅↔ (C) ↔~˄pq˅ ~~pq, pq˄~p~ ~q˅↔ (D) ↔~˄pq˅ ~p~q, pq˄~p~~q˅↔

Last Answer : (B) ↔~˄pq˅ ~p~q, pq˄~p~q~˅↔

Consider a 32 - bit microprocessor, with a 16 - bit external data bus, driven by an 8 MHz input clock. Assume that the microprocessor has a bus cycle whose minimum duration equals four input clock cycles. What is the maximum data transfer rate for this microprocessor? (A) 8x106 bytes/sec (B) 4x106 bytes/sec (C) 16x106 bytes/sec (D) 4x109 bytes/sec

Description : Consider a 32 - bit microprocessor, with a 16 - bit external data bus, driven by an 8 MHz input clock. Assume that the microprocessor has a bus cycle whose minimum duration equals four input clock cycles. What ... (A) 8x106 bytes/sec (B) 4x106 bytes/sec (C) 16x106 bytes/sec (D) 4x109 bytes/sec 

Last Answer : (B) 4x106 bytes/sec

Write SQL query to create a table “BOOKS” with the following structure: Table: BOOKS -Technology

Description : Write SQL query to create a table “BOOKS” with the following structure: Table: BOOKS -Technology

Last Answer : Create table Books(BOOK_ID Integer (2) Primary Key,BOOK_NAME Varchar (20),CATEGORY Varchar (20),ISSUE_DATE Date);

Write SQL query to create a table “Registration” with the following structure: -Technology

Description : Write SQL query to create a table “Registration” with the following structure: -Technology

Last Answer : Create table Registration(Reg_Id Integer(2) Primary Key,Name varchar(20),Course varchar(10),Join_Dt date);

Write SQL query to create a table Inventory with the following structure : -Technology

Description : Write SQL query to create a table Inventory with the following structure : -Technology

Last Answer : CREATE TABLE Inventory(Material Id Integer Primary Key,Material Varchar (50) NOT NULL,Category Char,DatePurchase Date) :

Write SQL query to create a table Player with the following structure : -Technology

Description : Write SQL query to create a table Player with the following structure : -Technology

Last Answer : CREATE TABLE Player(};

Write SQL Query commands based on the following table: -Technology

Description : Write SQL Query commands based on the following table: -Technology

Last Answer : This answer was deleted by our moderators...

Consider a subnet with 720 routers. If a three-level hierarchy is choosen with eight clusters, each containing 9 regions of 10 routers, then total number of entries in the routing table is ................... (A) 25 (B) 27 (C) 53 (D) 72

Description : Consider a subnet with 720 routers. If a three-level hierarchy is choosen with eight clusters, each containing 9 regions of 10 routers, then total number of entries in the routing table is ................... (A) 25 (B) 27 (C) 53 (D) 72

Last Answer : Answer: A  Explanation: Each router needs 10 entries for local routers, 8 entries for routing to other regions within its own cluster, and 7 entries for distant clusters, for a total of 25 entries.

The ....... command can be used to makes changes in the rows of a table in SQL. -Technology

Description : The ....... command can be used to makes changes in the rows of a table in SQL. -Technology

Last Answer : The update command can be used to makes changes in the rows of a table in SQL.

Consider an array A[20, 10], assume 4 words per memory cell and the base address of array A is 100. What is the address of A[11, 5] ? Assume row major storage. (A) 560 (B) 565 (C) 570 (D) 575

Description : Consider an array A[20, 10], assume 4 words per memory cell and the base address of array A is 100. What is the address of A[11, 5] ? Assume row major storage. (A) 560 (B) 565 (C) 570 (D) 575

Last Answer : (A) 560

Consider the following Entity-Relationship (E-R) diagram and three possible relationship sets (I, II and III) for this E-R diagram: Image If different symbols stand for different values (e.g., t1 is definitely not equal to t2), then which of the above could not be the relationship set for the E-R diagram ? (A) I only (B) I and II only (C) II only (D) I, II and III

Description : Consider the following Entity-Relationship (E-R) diagram and three possible relationship sets (I, II and III) for this E-R diagram: If different symbols stand for different values (e.g., t1 is definitely not equal to t2 ... diagram ? (A) I only (B) I and II only (C) II only (D) I, II and III

Last Answer : (A) I only

The number of function points of a proposed system is calculated as 500. Suppose that the system is planned to be developed in Java and the LOC/FP ratio of Java is 50. Estimate the effort (E) required to complete the project using the effort formula of basic COCOMO given below: E = a(KLOC)b Assume that the values of a and b are 2.5 and 1.0 respectively. (A) 25 person months (B) 75 person months (C) 62.5 person months (D) 72.5 person months

Description : The number of function points of a proposed system is calculated as 500. Suppose that the system is planned to be developed in Java and the LOC/FP ratio of Java is 50. Estimate the effort (E) required to ... ) 25 person months (B) 75 person months (C) 62.5 person months (D) 72.5 person months

Last Answer : (C) 62.5 person months 

Consider a program that consists of 8 pages (from 0 to 7) and we have 4 page frames in the physical memory for the pages. The page reference string is : 1 2 3 2 5 6 3 4 6 3 7 3 1 5 3 6 3 4 2 4 3 4 5 1 The number of page faults in LRU and optimal page replacement algorithms are respectively (without including initial page faults to fill available page frames with pages): (A) 9 and 6 (B) 10 and 7 (C) 9 and 7 (D) 10 and 6

Description : Consider a program that consists of 8 pages (from 0 to 7) and we have 4 page frames in the physical memory for the pages. The page reference string is :  1 2 3 2 5 6 3 4 6 3 7 3 1 5 3 6 3 4 2 4 3 4 5 ... to fill available page frames with pages): (A) 9 and 6 (B) 10 and 7 (C) 9 and 7 (D) 10 and 6

Last Answer : (B) 10 and 7

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

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

Consider a system having ‘m’ resources of the same type. These resources are shared by three processes P1, P2 and P3 which have peak demands of 2, 5 and 7 resources respectively. For what value of ‘m’ deadlock will not occur? (A) 70 (B) 14 (C) 13 (D) 7

Description : Consider a system having ‘m’ resources of the same type. These resources are shared by three processes P1, P2 and P3 which have peak demands of 2, 5 and 7 resources respectively. For what value of ‘m’ deadlock will not occur? (A) 70 (B) 14 (C) 13 (D) 7

Last Answer : (B) 14

Which of the following is a legal expression in SQL? (A) SELECT NULL FROM EMPLOYEE; (B) SELECT NAME FROM EMPLOYEE; (C) SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL; (D) None of the above

Description : Which of the following is a legal expression in SQL? (A) SELECT NULL FROM EMPLOYEE; (B) SELECT NAME FROM EMPLOYEE; (C) SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL; (D) None of the above

Last Answer : B) SELECT NAME FROM EMPLOYEE;

Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table: Image I: {B} II: {B, C} III: {A, D} IV: {C, D} If different symbols stand for different values in the table (e.g., d1 is definitely not equal to d2), then which of the above could not be the candidate key for the database table? (A) I and III only (B) III and IV only (C) II only (D) I only

Description : Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table: I: {B} II: {B, C} III: {A, D} IV: {C, D} If ... the database table? (A) I and III only (B) III and IV only (C) II only (D) I only

Last Answer : (C) II only

Which can be used to delete all the rows if a table? A) Delete * from table_name B) Delete from table_name C) Delete table_name D) all rows cannot be deleted at a time.

Description : Which can be used to delete all the rows if a table? A) Delete * from table_name B) Delete from table_name C) Delete table_name D) all rows cannot be deleted at a time.

Last Answer : A) Delete * from table_name

…………….. is used to determine whether of a table contains duplicate rows. A) Unique predicate B) Like Predicate C) Null predicate D) In predicate

Description : …………….. is used to determine whether of a table contains duplicate rows. A) Unique predicate B) Like Predicate C) Null predicate D) In predicate

Last Answer : A) Unique predicate

Given two jugs of capacities 5 litres and 3 litres with no measuring markers on them. Assume that there is endless supply of water. Then the minimum number of states to measure 4 litres water will be (A) 3 (B) 4 (C) 5 (D) 7

Description : Given two jugs of capacities 5 litres and 3 litres with no measuring markers on them. Assume that there is endless supply of water. Then the minimum number of states to measure 4 litres water will be (A) 3 (B) 4 (C) 5 (D) 7

Last Answer : (D) 7

SQL server stores index information in the ………… system table A) systindexes B) systemindexes C) sysind D) sysindexes

Description : SQL server stores index information in the ………… system table A) systindexes B) systemindexes C) sysind D) sysindexes

Last Answer : D) sysindexes