MCQOPTIONS
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MCQOPTIONS
This section includes 41 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The most commonly used operation in relational algebra for projecting a set of tuple from a relation is |
| A. | Join |
| B. | Projection |
| C. | Select |
| D. | Union |
| Answer» D. Union | |
| 2. |
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. |
| A. | Instance, Schema |
| B. | Relation, Schema |
| C. | Relation, Domain |
| D. | Schema, Instance |
| Answer» E. | |
| 3. |
A functional dependency f on R is _______ by a set of functional dependencies F on r if every instance of r(R) that satisfies f also satisfies F. |
| A. | Logically Defined |
| B. | Logically Derived |
| C. | Logically implied |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 4. |
To specify the foreign keys in relations referencing temporal data we need to specify _______ |
| A. | The time interval |
| B. | The Boolean value for the working |
| C. | The integer corresponding to the relation number |
| D. | None of the mentioned |
| Answer» B. The Boolean value for the working | |
| 5. |
An instance of a relation that satisfies all real world constraints is known as? |
| A. | Proper relation |
| B. | Ideal relation |
| C. | Perfect relation |
| D. | Legal relation |
| Answer» E. | |
| 6. |
The ______ is the one in which the primary key of one relation is used as a normal attribute in another relation. |
| A. | Referential relation |
| B. | Referencing relation |
| C. | Referenced relation |
| D. | Referred relation |
| Answer» D. Referred relation | |
| 7. |
If K → R then K is said to be the _______ of R |
| A. | Candidate key |
| B. | Foreign key |
| C. | Super key |
| D. | Domain |
| Answer» D. Domain | |
| 8. |
Student(ID, name, dept name, tot_cred)In this query which attribute form the primary key? |
| A. | Name |
| B. | Dept |
| C. | Tot_cred |
| D. | ID |
| Answer» E. | |
| 9. |
A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys. |
| A. | Schema diagram |
| B. | Relational algebra |
| C. | Database diagram |
| D. | Schema flow |
| Answer» B. Relational algebra | |
| 10. |
Which one of the following is a procedural language ? |
| A. | Domain relational calculus |
| B. | Tuple relational calculus |
| C. | Relational algebra |
| D. | Query language |
| Answer» D. Query language | |
| 11. |
Which of the following is not a condition for the third normal form in the case of X→Y? |
| A. | X→ Y is trivial |
| B. | X is the superkey for R |
| C. | Each attribute in Y-X is a candidate key for R |
| D. | Each attribute in X-Y is a candidate key for R |
| Answer» E. | |
| 12. |
X → Y holds on a schema k(K) if? |
| A. | At least one legal instance satisfies the functional dependency |
| B. | No legal instance satisfies the functional dependency |
| C. | Each and every legal instance satisfies the functional dependency |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 13. |
Which of the following is the time of temporal data that record when a fact was recorded in a database? |
| A. | Transaction time |
| B. | Valid time |
| C. | Enter time |
| D. | Exit time |
| Answer» B. Valid time | |
| 14. |
A _________ Fc for F is a set of dependencies such that F logically implies all dependencies in Fc, and Fc logically implies all dependencies in F. |
| A. | Canonical cover |
| B. | Complete cover |
| C. | Canonical dependency |
| D. | Canonical clause |
| Answer» B. Complete cover | |
| 15. |
State true or false: The fourth normal form does not exist and it is instead called as the BCNF. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 16. |
Choose the option that correctly explains in words, the function of the following relational algebra expression:σyear≥2009 (book ⋈ borrow) |
| A. | Selects all tuples from the Cartesian product of book and borrow |
| B. | Selects all the tuples from the natural join of book and borrow wherever the year is lesser than 2009 |
| C. | Selects all the tuples from the natural join of book and student wherever the year is greater than or equal to 2009 |
| D. | Selects all tuples from the Cartesian product of book and borrow wherever the year is greater than or equal to 2009 |
| Answer» C. Selects all the tuples from the natural join of book and student wherever the year is greater than or equal to 2009 | |
| 17. |
The result which operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match. |
| A. | Join |
| B. | Cartesian product |
| C. | Intersection |
| D. | Set difference |
| Answer» C. Intersection | |
| 18. |
State true or false: If a relation consists of a foreign key, then it is called a referenced relation of the foreign key dependency. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 19. |
State true or false: A functional dependency must first satisfy the second normal form to satisfy the third normal form. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 20. |
If B is an attribute and A→B, Then B is said to be ________ by a. |
| A. | Logically implied |
| B. | Functionally implied |
| C. | Logically determined |
| D. | Functionally determined |
| Answer» E. | |
| 21. |
We say that a decomposition having the property F’+ = F+ is a __________ decomposition. |
| A. | Dependency losing |
| B. | Dependency preserving |
| C. | Lossless |
| D. | None of the mentioned |
| Answer» C. Lossless | |
| 22. |
Which of the following is not a process of generating a good relational schema? |
| A. | Converting ER diagrams to relational schema |
| B. | Decomposing the relational schema while satisfying functional dependencies |
| C. | Joining multiple relations together to form a single relation containing all the attributes |
| D. | A design of relations which is then tested and modified to satisfy given normal forms |
| Answer» D. A design of relations which is then tested and modified to satisfy given normal forms | |
| 23. |
What does the “x” operator do in relational algebra? |
| A. | Output specified attributes from all rows of the input relation. Remove duplicate tuples from the output |
| B. | Output pairs of rows from the two input relations that have the same value on all attributes that have the same name |
| C. | Output all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes) |
| D. | Returns the rows of the input relation that satisfy the predicate |
| Answer» D. Returns the rows of the input relation that satisfy the predicate | |
| 24. |
The_____ operation allows the combining of two relations by merging pairs of tuples, one from each relation, into a single tuple. |
| A. | Select |
| B. | Join |
| C. | Union |
| D. | Intersection |
| Answer» C. Union | |
| 25. |
If A→B, A→ C then which of the following is true? |
| A. | A→BC |
| B. | A→B |
| C. | A→C |
| D. | All of the mentioned |
| Answer» E. | |
| 26. |
Using which language can a user request information from a database ? |
| A. | Query |
| B. | Relational |
| C. | Structural |
| D. | Compiler |
| Answer» B. Relational | |
| 27. |
Statement 1: A tuple is a row in a relationStatement 2: Existence of multiple foreign keys in a same relation is possible |
| A. | Both the statements are true |
| B. | Statement 1 is correct but Statement 2 is false |
| C. | Statement 1 is false but Statement 2 is correct |
| D. | Both the statements are false |
| Answer» B. Statement 1 is correct but Statement 2 is false | |
| 28. |
State true or false: Overlapping time intervals cannot be prevented |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 29. |
F+ is called as the ________ of F |
| A. | Closure |
| B. | Sum |
| C. | Cartesian product |
| D. | None of the mentioned |
| Answer» B. Sum | |
| 30. |
Course(course_id,sec_id,semester)Here the course_id,sec_id and semester are __________ and course is a _________ |
| A. | Relations, Attribute |
| B. | Attributes, Relation |
| C. | Tuple, Relation |
| D. | Tuple, Attributes |
| Answer» C. Tuple, Relation | |
| 31. |
The _______ operator takes the results of two queries and returns only rows that appear in both result sets. |
| A. | Union |
| B. | Intersect |
| C. | Difference |
| D. | Projection |
| Answer» C. Difference | |
| 32. |
What action does ⋈ operator perform in relational algebra |
| A. | Output specified attributes from all rows of the input relation and remove duplicate tuples from the output |
| B. | Outputs pairs of rows from the two input relations that have the same value on all attributes that have the same name |
| C. | Output all pairs of rows from the two input relations (regardless of whether or not they have the same values on common attributes) |
| D. | Return rows of the input relation that satisfy the predicate |
| Answer» B. Outputs pairs of rows from the two input relations that have the same value on all attributes that have the same name | |
| 33. |
The _______operation performs a set union of two “similarly structured” tables |
| A. | Union |
| B. | Join |
| C. | Product |
| D. | Intersect |
| Answer» B. Join | |
| 34. |
State true or false: Armstrong’s axioms allow us to generate all F+ for any given F |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 35. |
X→ Y is trivial if? |
| A. | X ⊂ Y |
| B. | Y ⊂ X |
| C. | X ⊇ Y |
| D. | None of the mentioned |
| Answer» B. Y ⊂ X | |
| 36. |
The _________ provides a set of operations that take one or more relations as input and return a relation as an output. |
| A. | Schematic representation |
| B. | Relational algebra |
| C. | Scheme diagram |
| D. | Relation flow |
| Answer» C. Scheme diagram | |
| 37. |
Which of the following is not a condition for X→ Y in Boyce codd normal form? |
| A. | X → Y is trivial |
| B. | X is the superkey for the relational schema R |
| C. | Y is the superkey for the relational schema R |
| D. | All of the mentioned |
| Answer» D. All of the mentioned | |
| 38. |
The data that have a time interval associated with them during which they are valid are called as ________ |
| A. | Timed data |
| B. | Temporal data |
| C. | Model data |
| D. | Clocked data |
| Answer» C. Model data | |
| 39. |
State true or false: If a relational schema is in _______ NF and A is a subset of R and B is also a subset of R then it is that A is a superkey is a trivial multi values dependency. |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» E. | |
| 40. |
Which of the following normal forms does not exist? |
| A. | BCNF |
| B. | PJNF |
| C. | 5NF |
| D. | None of the mentioned |
| Answer» E. | |
| 41. |
The _______ is a set of all functional and multi values dependencies implied by a set of functional dependencies |
| A. | Star |
| B. | Closure |
| C. | Derivation |
| D. | Evolution |
| Answer» C. Derivation | |