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MCQOPTIONS
This section includes 1917 Mcqs, each offering curated multiple-choice questions to sharpen your UGC-NET knowledge and support exam preparation. Choose a topic below to get started.
| 1151. |
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. | eliminating number of anomalies that could otherwise occur with inserts and deletes |
| D. | ensuring that functional dependencies are enforced |
| Answer» B. eliminating uncontrolled redundancy of data stored in the database | |
| 1152. |
Which of the following is/are true with reference to 'view' in DBMS?(a) A 'view' is a special stored procedure executed when certain event occurs.(b) A 'view' is a virtual table, which occurs after executing a pre-compiled query. |
| A. | Only (a) is true |
| B. | Only (b) is true |
| C. | Both (a) and (b) are true |
| D. | Neither (a) nor (b) are true |
| Answer» C. Both (a) and (b) are true | |
| 1153. |
Data Scrubbing is |
| A. | A process to upgrade the quality of data after it is moved into a data warehouse. |
| B. | A process to reject data from the data warehouse and to create the necessary indexes. |
| C. | A process to load the data in the data warehouse and to create the necessary indexes. |
| D. | A process to upgrade the quality of data before it is moved into a data warehouse. |
| Answer» E. | |
| 1154. |
A relation R={A,B,C,D,E,F,G} is given with following set of functional dependencies:F={AD→E, BE→F, B→C, AF→G}Which of the following is a candidate key? |
| A. | A |
| B. | AB |
| C. | ABC |
| D. | ABD |
| Answer» E. | |
| 1155. |
Consider a schema R(MNPQ) and functional dependencies M→N, P→Q. Then the decomposition of R into R1(MN) and R2(PQ) is _______ |
| A. | Dependency preserving but not lossless join |
| B. | Dependency preserving and lossless join |
| C. | Lossless join but not dependency preserving |
| D. | Neither dependency preserving nor lossless join |
| Answer» B. Dependency preserving and lossless join | |
| 1156. |
Match the following :List-I(1) Determinants(2) Candidate key(3) Non-redundancy(4) Functional dependencyList-II(a) No attribute can be added(b) Uniquely identified a row(c) A constraint between two attribute(d) Group of attributes on the left hand side of arrow of function dependency. |
| A. | 1 – d, 2 – b, 3 – a, 4 – c |
| B. | 2 – d, 3 – a, 1 – b, 4 – c |
| C. | 4 – a, 3 – b, 2 – c, 1 – d |
| D. | 3 – a, 4 – b, 1 – c, 2 – d |
| Answer» B. 2 – d, 3 – a, 1 – b, 4 – c | |
| 1157. |
Views are useful for ................. unwanted information, and for collecting together information from more than one relation into a single view. |
| A. | Hiding |
| B. | Deleting |
| C. | Highlighting |
| D. | All of the above |
| Answer» B. Deleting | |
| 1158. |
Which statement is false regarding data independence ? |
| A. | Hierarchical data model suffers from data independence |
| B. | Network model suffers from data independence |
| C. | Relational model suffers only from logical data independence |
| D. | Relational model suffers only from physical data independence |
| Answer» D. Relational model suffers only from physical data independence | |
| 1159. |
In DBMS, deferred update means: |
| A. | All the updates are done first but the entries are made in the log file later |
| B. | All the log files entries are made first but the actual updates are done later |
| C. | Every update is done first followed by a writing on the log file |
| D. | Changes in the views are deferred till a query asks for a view |
| Answer» C. Every update is done first followed by a writing on the log file | |
| 1160. |
The Global conceptual Schema in a distributed database contains information about global relations. The condition that all the data of the global relation must be mapped into the fragments, that is, it must not happen that a data item which belongs to a global relation does not belong to any fragment, is called : |
| A. | Disjointness condition |
| B. | Completeness condition |
| C. | Reconstruction condition |
| D. | Aggregation condition |
| Answer» C. Reconstruction condition | |
| 1161. |
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 |
| Answer» D. 21 | |
| 1162. |
Which data management language component enabled the DBA to define the schema components? |
| A. | DML |
| B. | Sub-schema DLL |
| C. | Schema DLL |
| D. | All of these |
| Answer» D. All of these | |
| 1163. |
The entity type on which the ................. type depends is called the identifying owner. |
| A. | Strong entity |
| B. | Relationship |
| C. | Weak entity |
| D. | E - R |
| Answer» D. E - R | |
| 1164. |
Match the following:a. Foreign keys i. Domain constraintb. Private key ii. Referential integrityc. Event control action model iii. Encryptiond. Data security iv. TriggerCodes: a b c d |
| A. | iii ii i iv |
| B. | ii i iv iii |
| C. | iii iv i ii |
| D. | i ii iii iv |
| Answer» C. iii iv i ii | |
| 1165. |
A Transaction Manager is which of the following ? |
| A. | Maintains a log of transactions |
| B. | Maintains before and after database images |
| C. | Maintains appropriate concurrency control |
| D. | All of the above |
| Answer» E. | |
| 1166. |
What kind of mechanism is to be taken into account for converting a weak entity set into strong entity set in entity-relationship diagram? |
| A. | Generalization |
| B. | Aggregation |
| C. | Specialization |
| D. | Adding suitable attributes |
| Answer» E. | |
| 1167. |
Consider the following statements:I. Re-construction operation used in mixed fragmentation satisfies commutative rule.II. Re-construction operation used in vertical fragmentation satisfies commutative ruleWhich of the following is correct? |
| A. | I |
| B. | II |
| C. | Both are correct |
| D. | None of the statements are correct |
| Answer» C. Both are correct | |
| 1168. |
Consider the following relational schemas for a library database: Book (Title, Author, Catalog_no, Publisher, Year, Price) Collection (Title, Author, with the following dependencies :I. Title, Author —> Catalog_noII. Catalog_no —> Title, Author, Publisher, YearIII. Publisher, Title, Year —> PriceAssume (Author, Title) is the key for both schemas. Which one of the following is true ? |
| A. | Both Book and Collection are in BCNF |
| B. | Both Book and Collection are in 3NF |
| C. | Book is in 2NF and Collection in 3NF |
| D. | Both Book and Collection are in 2NF |
| Answer» D. Both Book and Collection are in 2NF | |
| 1169. |
An Assertion is a predicate expressing a condition we wish database to always satisfy. The correct syntax for Assertion is : |
| A. | CREATE ASSERTION',ASSERTION Name', CHECK',Predicate', |
| B. | CREATE ASSERTION 'ASSERTION NAME' |
| C. | CREATE ASSERTION, CHECK Predicate |
| D. | SELECT ASSERTION |
| Answer» B. CREATE ASSERTION 'ASSERTION NAME' | |
| 1170. |
Consider the following schemasBranch = (Branch-name, Assets, Branch-city)Customer = (Customer-name, Bank name, Customer-city)Borrow = (Branch~name, loannumber, customer account-number)Deposit = (Branch-name, Accountnumber,Customer-name, Balance)Using relational Algebra, the Query that finds customers who have balance more than 10,000 is_______ |
| A. | πcustomer-name (σbalance > 1000(Deposit)) |
| B. | σcustomer-name (σbalance > 1000(Deposit)) |
| C. | πcustomer-name (σbalance > 1000(Borrow)) |
| D. | σcustomer-name (σbalance > 1000(Borrow)) |
| Answer» B. σcustomer-name (σbalance > 1000(Deposit)) | |
| 1171. |
An attribute A of datatype varchar(20) has value 'Ram' and the attribute B of datatype char(20) has value 'Sita' in oracle. The attribute A has .......... memory spaces and B has .......... memory spaces. |
| A. | 20, 20 |
| B. | 3, 20 |
| C. | 3, 4 |
| D. | 20, 4 |
| Answer» C. 3, 4 | |
| 1172. |
If a relation is in 2NF then: |
| A. | every candidate key is a primary key |
| B. | every non-prime attribute is fully functionally dependent on each relation key |
| C. | every attribute is functionally independent |
| D. | every relational key is a primary key |
| Answer» C. every attribute is functionally independent | |
| 1173. |
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.course =5) |
| A. | Q.1 |
| B. | Q.2 |
| C. | Both Q.1 and Q.2 |
| D. | Neither Q. 1 nor Q. 2 |
| Answer» E. | |
| 1174. |
Based on the cardinality ratio and participation______________associated with a relationship type, choose either the Foreign Key Design, the Cross Referencing Design or Mutual Referencing Design. |
| A. | Entity |
| B. | Constraints |
| C. | Rules |
| D. | Keys |
| Answer» C. Rules | |
| 1175. |
One approach to standardizing storing of data: |
| A. | MIS |
| B. | CODASYL |
| C. | Structured Programming |
| D. | None of the above |
| Answer» C. Structured Programming | |
| 1176. |
An entity instance is a single occurrence of an ………….. |
| A. | entity type |
| B. | relationship type |
| C. | entity and relationship type |
| D. | None of these |
| Answer» B. relationship type | |
| 1177. |
Given an open address hash table with load factor a < 1, the expected number of probes in a successful search is |
| A. | Atmost 1/α ln (1-α/α) |
| B. | Atmost 1/α ln (1/1-α) |
| C. | Atleast 1/α ln (1/1-α) |
| D. | Atleast 1/α ln (α/1-α) |
| Answer» C. Atleast 1/α ln (1/1-α) | |
| 1178. |
Let pk(R) denotes primary key of relation R. A many-to-one relationship that exists between two relations R1 and R2 can be expressed as follows: |
| A. | pk(R2)→pk(R1) |
| B. | pk(R1)→pk(R2) |
| C. | pk(R2)→R1∩R2 |
| D. | pk(R1)→R1∩R2 |
| Answer» C. pk(R2)→R1∩R2 | |
| 1179. |
Aggregate functions in SQL are: |
| A. | GREATEST, LEAST and ABS |
| B. | SUM, COUNT and AVG |
| C. | UPPER, LOWER and LENGTH |
| D. | SQRT, POWER and MOD |
| Answer» C. UPPER, LOWER and LENGTH | |
| 1180. |
Which command is the fastest among the following ? |
| A. | COPY TO < NEW FILE > |
| B. | COPY STRUCTURE TO < NEW FILE > |
| C. | COPY FILE < FILE 1 > < FILE 2 > |
| D. | COPY TO MFILE-DAT DELIMITED |
| Answer» C. COPY FILE < FILE 1 > < FILE 2 > | |
| 1181. |
Match the following :(a) Create (i) The E-R Model(b) Select (ii) Relationship Model(c) Rectangle (iii) DDL(d) Record (iv) DMLCodes : (a) (b) (c) (d) |
| A. | (iii) (iv) (i) (ii) |
| B. | (iv) (iii) (ii) (i) |
| C. | (iv) (iii) (i) (ii) |
| D. | (iii) (iv) (ii) (i) |
| Answer» B. (iv) (iii) (ii) (i) | |
| 1182. |
The problem that occurs when one transaction updates a database item and then the transaction fails for some reason is ……………. |
| A. | Temporary Select Problem |
| B. | Temporary Modify Problem |
| C. | Dirty Read Problem |
| D. | None of the above |
| Answer» D. None of the above | |
| 1183. |
A B+ tree index is to be built on the name attribute of the relation STUDENT. Assume that all students names are of length 8 bytes, disk block are of size 512 bytes and index pointers are of size 4 bytes. Given this scenario what would be the best choice of the degree (i.e. the number of pointers per node) of the B+ tree ? |
| A. | 16 |
| B. | 42 |
| C. | 43 |
| D. | 44 |
| Answer» B. 42 | |
| 1184. |
An attribute or set of attributes within one relation that matches the candidate key of some(possibly the same) relation: |
| A. | Super key |
| B. | Candidate key |
| C. | Primary key |
| D. | Foreign key |
| Answer» E. | |
| 1185. |
Consider a relation R (A, B, C, D, E, F, G, H), where each attribute is atomic, and following functional dependencies exist.CH → GA → BCB → CFHE → AF → EGThe relation R is .................... |
| A. | in 1NF but not in 2NF |
| B. | in 2NF but not in 3NF |
| C. | in 3NF but not in BCNF |
| D. | in BCNF |
| Answer» B. in 2NF but not in 3NF | |
| 1186. |
Integrity constraints ensure that changes made to the database by authorized users do not result into loss of data consistency. Which of the following statement(s) is (are) true w.r.t. the examples of integrity constraints?(A) An instructor Id. No. cannot be null, provided Instructor Id. No. being primary key.(B) No two citizens have same Adhar-Id.(C) Budget of a company must be zero. |
| A. | (A), (B) and (C) are true |
| B. | (A) false, (B) and (C) are true |
| C. | (A) and (B) are true; (C) false |
| D. | (A), (B) and (C) are false |
| Answer» D. (A), (B) and (C) are false | |
| 1187. |
The basic variants of time-stampbased method of concurrency control are |
| A. | Total time stamp-ordering |
| B. | Partial time stamp ordering |
| C. | Multiversion Time stamp ordering |
| D. | All of the above |
| Answer» E. | |
| 1188. |
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→CB→DThe relation R is in ................ |
| A. | First normal form but not in second normal form |
| B. | Both in first normal form as well as in second normal form |
| C. | Second normal form but not in third normal form |
| D. | Both in second normal form as well as in third normal form |
| Answer» B. Both in first normal form as well as in second normal form | |
| 1189. |
A relation R={A,B,C,D,E,F} is given with following set of functional dependencies:F={A→B,AD→C,B→F,A→E}.Which of the following is Candidate Key? |
| A. | A |
| B. | AC |
| C. | AD |
| D. | None of these |
| Answer» D. None of these | |
| 1190. |
A sub class having more than one super class is called: |
| A. | Category |
| B. | Classification |
| C. | Combination |
| D. | Partial Participation |
| Answer» B. Classification | |
| 1191. |
Which of the following statements is FALSE about weak entity set ? |
| A. | Weak entities can be deleted. automatically when their strong entity is deleted |
| B. | Weak entity set avoids the data duplication and consequent possible inconsistencies caused by duplicating.the key of the strong entity |
| C. | A weak entity set has no primary keys unless attributes of the strong entity set on which it depends are included |
| D. | Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set |
| Answer» E. | |
| 1192. |
A primary key for an entity is: |
| A. | a candidate key |
| B. | any attribute |
| C. | a unique attribute |
| D. | a super key |
| Answer» D. a super key | |
| 1193. |
The STUDENT information in a university stored in the relation STUDENT (Name, SEX, Marks, DEPT_Name)Consider the following SQL Query SELECT DEPT_Name from STUDENT where SEX = 'M' group by DEPT_Name having avg (Marks)>SELECT avg (Marks) from STUDENT. It returns the Name of the Department for which: |
| A. | The Average marks of Male students is more than the average marks of students in the same Department |
| B. | The average marks of male students is more than the average marks of students in the University |
| C. | The average marks of male students is more than the average marks of male students in the University |
| D. | The average marks of students is more than the average marks of male students in the University |
| Answer» C. The average marks of male students is more than the average marks of male students in the University | |
| 1194. |
If h is chosen from a universal collection of hash functions and is used to hash n keys into a table of size m, where n?m, the expected number of collisions involving a particular key x is less than ................... |
| A. | 1 |
| B. | 1/n |
| C. | 1/m |
| D. | n/m |
| Answer» B. 1/n | |
| 1195. |
Which of the following is the recovery management technique in DDBMS ? |
| A. | 2PC (Two Phase Commit) |
| B. | Backup |
| C. | Immediate update |
| D. | All of the above |
| Answer» E. | |
| 1196. |
Match the following:Set-II. 2 NFII. 3 NFIII. 4 NFIV. 5 NFSet-II(a) transitive dependencies eliminated(b) multivalued attribute removed(c) contain no partial functional dependencies(d) contains no join dependencyCodes : I II III IV |
| A. | (a) (c) (b) (d) |
| B. | (d) (a) (b) (c) |
| C. | (c) (d) (a) (b) |
| D. | (d) (b) (a) (c) |
| Answer» C. (c) (d) (a) (b) | |
| 1197. |
The following IP address format refers to: |
| A. | Class A Addresses |
| B. | Class B Addresses |
| C. | Class C Addresses |
| D. | Class D Addresses |
| Answer» D. Class D Addresses | |
| 1198. |
Encrypt the Message “HELLO MY DEARZ” using Transposition Cipher with |
| A. | HLLEO YM AEDRZ |
| B. | EHOLL ZYM RAED |
| C. | ELHL MDOY AZER |
| D. | ELHL DOMY ZAER |
| Answer» D. ELHL DOMY ZAER | |
| 1199. |
The channel capacity of a band-limited Gaussian channel is given by: |
| A. | B log2(2+S/N) |
| B. | B log2(1+S/N) |
| C. | B log10(1+S/N) |
| D. | B loge(1+S/N) |
| Answer» C. B log10(1+S/N) | |
| 1200. |
Process of mapping a network interface IP address to its hardware address: |
| A. | ARP |
| B. | RARP |
| C. | ICMP |
| D. | IGMP |
| Answer» B. RARP | |