Relational Modal Set 2
Computer Science Engineering (CSE),
Bachelor of Science in Computer Science FY (BSc CS),
Bachelor of Science in Computer Science SY (BSc CS),
Bachelor of Science in Information Technology SY (BSc IT),
Bachelor of Computer Applications (BCA),
Bachelor of Business Administration in Computer Applications (BBA [CA]),
Bachelor of Science in Information Technology (BSc IT),
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This set of DataBase Management System (DBMS) Multiple Choice Questions & Answers (MCQs) focuses on Relational Modal Set 2
Q1 | For select operation the ________ appear in the subscript and the ___________ argumentappears in the paranthesis after the sigmA:)
- Predicates, relation
- Relation, Predicates
- Operation, Predicates
- Relation, Operation
Q2 | The ___________ operation, denoted by −, allows us to find tuples that are in one relationbut are not in another.
- Union
- Set-difference
- Difference
- Intersection
Q3 | In precedence of set operators, the expression is evaluated from
- Left to left
- Left to right
- Right to left
- From user specification
Q4 | Which one of the following is a set of one or more attributes taken collectively to uniquelyidentify a record?
- Candidate key
- Sub key
- Super key
- Foreign key
Q5 | Consider attributes ID, CITY and NAME. Which one of this can be considered as a superkey?
- NAME
- ID
- CITY
- CITY, ID
Q6 | A _____ is a property of the entire relation, rather than of the individual tuples in whicheach tuple is unique.
- Rows
- Key
- Attribute
- Fields
Q7 | An attribute in a relation is a foreign key if the _______ key from one relation is used as anattribute in that relation.
- Candidate
- Primary
- Super
- Sub
Q8 | The relation with the attribute which is the primary key is referenced in another relation.The relation which has the attribute as a primary key is called ______________
- Referential relation
- Referencing relation
- Referenced relation
- Referred relation
Q9 | The ______ is the one in which the primary key of one relation is used as a normalattribute in another relation.
- Referential relation
- Referencing relation
- Referenced relation
- Referred relation
Q10 | A _________ integrity constraint requires that the values appearing in specified attributesof any tuple in the referencing relation also appear in specified attributes of at least one tuple inthe referenced relation.
- Referential
- Referencing
- Specific
- Primary
Q11 | Database __________ which is the logical design of the database, and the database_______ which is a snapshot of the data in the database at a given instant in time.
- Instance, Schema
- Relation, Schema
- Relation, Domain
- Schema, Instance
Q12 | Course(course_id,sec_id,semester)Here the course_id,sec_id and semester are __________ and course is a _________
- Relations, Attribute
- Attributes, Relation
- Tuple, Relation
- Tuple, Attributes
Q13 | Department (dept name, building, budget) and Employee (employee_id, name, dept name, salary) Here the dept_name attribute appears in both the relations. Here using common attributes in relation schema is one way of relating ___________ relations.
- Attributes of common
- Tuple of common
- Tuple of distinct
- Attributes of distinct
Q14 | A domain is atomic if elements of the domain are considered to be ____________ units.
- Different
- Indivisbile
- Constant
- Divisible
Q15 | What action does ⋈ operator perform in relational algebra
- Output specified attributes from all rows of the input relation and remove duplicate tuples from the output
- Outputs pairs of rows from the two input relations that have the same value on all attributes that have the same name
- Output all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes)
- Return rows of the input relation that satisfy the predicate
Q16 | A relational database consists of a collection of
- Tables
- Fields
- Records
- Keys
Q17 | A ________ in a table represents a relationship among a set of values.
- Column
- Key
- Row
- Entry
Q18 | The term _______ is used to refer to a row.
- Attribute
- Tuple
- Field
- Instance
Q19 | The term attribute refers to a ___________ of a table.
- Record
- Column
- Tuple
- Key
Q20 | For each attribute of a relation, there is a set of permitted values, called the ________ ofthat attribute.
- Domain
- Relation
- Set
- Schema
Q21 | The tuples of the relations can be of ________ order.
- Any
- Same
- Sorted
- Constant
Q22 | Choose the correct statement regarding superkeys
- A superkey is an attribute or a group of multiple attributes that can uniquely identify a tuple
- A superkey is a tuple or a set of multiple tuples that can uniquely identify an attribute
- Every superkey is a candidate key
- A superkey is an attribute or a set of attributes that distinguish the relation from other relations
Q23 | What is an Instance of a Database?
- The logical design of the database system
- The entire set of attributes of the Database put together in a single relation
- The state of the database system at any given point of time
- The initial values inserted into the Database immediately after its creation
Q24 | What is a foreign key?
- A foreign key is a primary key of a relation which is an attribute in another relation
- A foreign key is a superkey of a relation which is an attribute in more than one other relations
- A foreign key is an attribute of a relation that is a primary key of another relation
- A foreign key is the primary key of a relation that does not occur anywhere else in the schema
Q25 | What does the “x” operator do in relational algebra?
- Output specified attributes from all rows of the input relation. Remove duplicate tuples from the output
- Output pairs of rows from the two input relations that have the same value on all attributes that have the same name
- Output all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes)
- Returns the rows of the input relation that satisfy the predicate