Relational Model DBMS UGC NET CSA
| Q1➡ | NTA UGC NET June 2021 |
Consider following two statements:
Statement I: Relational database schema represents the logical design of the database.
Statement II: Current snapshot of a relation only provides the degree of the relation.
In the context to the above statements, choose the correct option from the options given below:
|i ➥ Both Statement I and Statement II are FALSE|
|ii ➥ Both Statement I and Statement II are TRUE|
|iii ➥ Statement I is FALSE but Statement II is TRUE|
|iv ➥ Statement I is TRUE but Statement II is FALSE|
| Q2➡ | UGC NET December 2019 |
Find minimum number of tables required for converting the following entity relationship diagram into relational database?
|i ➥ 2|
|ii ➥ 4|
|iii ➥ 3|
|iv ➥ 5|
| Q3➡ | UGC NET JUNE 2019 |
Which of the following key constraints is required for functioning of foreign key in the context of relational database?
|i ➥ Unique key|
|ii ➥ Primary key|
|iii ➥ Candidate key|
|iv ➥ Check key|
| Q4➡ | UGC NET JUNE 2019 |
In relational database management, which of the following is/are property/properties of candidate key?
|i ➥ P only|
|ii ➥ Q only|
|iii ➥ Both P and Q|
|iv ➥ Neither P nor Q|
| Q5➡ | UGC NET JUNE 2019 |
Which of the following features is supported in the relational database model?
|i ➥ Complex data-types|
|ii ➥ Multivalued attributes|
|iii ➥ Association with multiplicities|
|iv ➥ Generalization relationship|
| Q6➡ | UGC NET JUNE 2019 |
Following table has two attributes Employee_id and Manager_id, where Employee_id is a primary key and manager_id is a foreign key referencing Employee_id with on-delete cascade:
On deleting the table (20,40), the set of other tuples that must be deleted to maintain the referential integrity of table is
|i ➥ (30,35) only|
|ii ➥ (30,35) and (35,20) only|
|iii ➥ (35,20) only|
|iv ➥ (40,45) and (25,40) only|
| Q7➡ | UGC NET JUNE 2018 |
Let R1(a,b,c) and R2(x,y,z) be two relations in which a is the foreign key of R1 that refers to the primary key of R2 . Consider following four options.
(a) Insert into R1
(b) Insert into R2
(c) Delete from R1
(d) Delete from R2
Which of the following is correct about the referential integrity constraint with respect to above ?
|i ➥ Operations (a) and (b) will cause violation.|
|ii ➥ Operations (b) and (c) will cause violation.|
|iii ➥ Operations (c) and (d) will cause violation.|
|iv ➥ Operations (d) and (a) will cause violation.|
| Q8➡ | UGC NET November 2017 Paper-II |
Match the following with respect to RDBMS :
|i ➥ (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)|
|ii ➥ (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)|
|iii ➥ (a)-(iv), (b)-(ii), (c)-(iii), (d)-(i)|
|iv ➥ (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)|
| Q9➡ | UGC NET January 2017 Paper-II |
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 ?
(1) An instructor Id. No. cannot be null, provided Instructor Id No. being primary key.
(2) No two citizens have same Adhar-Id.
(3) Budget of a company must be zero.
|i ➥ (1), (2) and (3) are true|
|ii ➥ (1) false, (2) and (3) are true.|
|iii ➥ (1) and (2) are true; (3) false.|
|iv ➥ (1), (2) and (3) are false|
| Q10➡ | UGC NET January 2017 Paper-II |
Let M and N be two entities in an E-R diagram with simple single value attributes.
R1 and R2 are two relationship between M and N, where as
R1 is one-to-many and R2 is many-to-many.
The minimum number of tables required to represent M, N, R1 and R2 in the relational model are ______.
|i ➥ 4|
|ii ➥ 6|
|iii ➥ 7|
|iv ➥ 3|
| Q11➡ | UGC NET January 2017 Paper-III |
Which one is correct w.r.t. RDBMS ?
|i ➥ primary key ⊆ super key ⊆ candidate key|
|ii ➥ primary key ⊆ candidate key ⊆ super key|
|iii ➥ super key ⊆ candidate key ⊆ primary key|
|iv ➥ super key ⊆ primary key ⊆ candidate key|
| Q12➡ | UGC NET July 2016 Paper-II |
In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as:
|i ➥ Referential integrity|
|ii ➥ Multi-valued dependency|
|iii ➥ Entity Integrity|
|iv ➥ Functional dependency|
| Q13➡ | UGC NET July 2016 Paper-II |
Which of the following statement(s) is/are FALSE in the context of Relational DBMS ?
I. Views in a database system are important because they help with access control by allowing users to see only a particular subset of the data in the database.
II. E-R diagrams are useful to logically model concepts.
III. An update anomaly is when it is not possible to store information unless some other, unrelated information is stored as well.
IV. SQL is a procedural language.
|i ➥ I and IV only|
|ii ➥ III and IV only|
|iii ➥ I, II and III only|
|iv ➥ II, III and IV only|
| Q14➡ | UGC NET July 2016 Paper-II |
In a relational database model, NULL values can be used for all but which one of the following ?
|i ➥ To allow duplicate tuples in the table by filling the primary key column(s) with NULL.|
|ii ➥ To avoid confusion with actual legitimate data values like 0 (zero) for integer columns and ’’ (the empty string) for string columns.|
|iii ➥ To leave columns in a tuple marked as ’’unknown’’ when the actual value is unknown.|
|iv ➥ To fill a column in a tuple when that column does not really ”exist” for that particular tuple.|