Home »
MCQs »
DBMS MCQs
DBMS Selection Operation in Query Processing MCQs
DBMS Selection Operation in Query Processing MCQs: This section contains multiple-choice questions and answers on Selection Operation in Query Processing in DBMS.
Submitted by Anushree Goswami, on May 19, 2022
1. The file scan performs the selection operation.
- Updation
- Insertion
- Selection
- Deletion
Answer: C) Selection
Explanation:
The file scan performs the selection operation.
Discuss this Question
2. Data is found and accessed by using ___ algorithms called file scans.
- Update
- Search
- Add
- Delete
Answer: B) Search
Explanation:
Data is found and accessed by using search algorithms called file scans.
Discuss this Question
3. As the lowest level of query processing, file scans are used.
- Middle
- Centre
- Highest
- Lowest
Answer: D) Lowest
Explanation:
As the lowest level of query processing, file scans are used.
Discuss this Question
4. A file scan reads a relation in an RDBMS or relational database system only if the whole relationship is stored in ___ file.
- Multiple
- Two
- Three
- One
Answer: D) One
Explanation:
A file scan reads a relation in an RDBMS or relational database system only if the whole relationship is stored in one file.
Discuss this Question
5. ____ search involves scanning each record to determine whether it meets the given selection criteria.
- Linear
- Cross
- Merge
- None
Answer: A) Linear
Explanation:
Linear search involves scanning each record to determine whether it meets the given selection criteria.
Discuss this Question
6. The linear search algorithm, on the other hand, is the ____ type of search, but it can be applied to any situation.
- Fastest
- Average
- Slowest
- None
Answer: C) Slowest
Explanation:
The linear search algorithm, on the other hand, is the slowest type of search, but it can be applied to any situation.
Discuss this Question
7. There's no need to take into account the ___ when using the Linear Search algorithm.
- Nature of Selection
- Availability of indices
- File Sequence
- All of the above
Answer: D) All of the above
Explanation:
There's no need to take into account the nature of selection, availability of indices, or file sequence when using the Linear Search algorithm.
Discuss this Question
8. Index ___ are another name for index-based search algorithm.
- Scans
- Logs
- Stacks
- Queues
Answer: A) Scans
Explanation:
Index scans are another name for index-based search algorithm.
Discuss this Question
9. ____ are the index structures used by index-based search algorithms.
- Access roads
- Access paths
- Access Terminal
- None
Answer: B) Access paths
Explanation:
Access paths are the index structures used by index-based search algorithms.
Discuss this Question
10. Data in a file can be ___ by using access paths.
- Accessed
- Located
- Both A and B
- None of the above
Answer: C) Both A and B
Explanation:
Data in a file can be accessed and located by using access paths.
Discuss this Question
11. Our selection condition is based on finding a record that satisfies the ____ condition in the index.
- Non-equality
- Equality
- Duality
- Non-duality
Answer: B) Equality
Explanation:
Our selection condition is based on finding a record that satisfies the equality condition in the index.
Discuss this Question
12. A key attribute having a primary key is compared for equality.
- Primary
- Alternate
- Composite
- None
Answer: A) Primary
Explanation:
A key attribute having a primary key is compared for equality.
Discuss this Question
13. We can fetch ___ record(s) with equality on key, as opposed to equality on non-key.
- One
- Two
- Three
- Multiple
Answer: D) Multiple
Explanation:
We can fetch multiple records with equality on key, as opposed to equality on non-key.
Discuss this Question
14. When the selection criteria specify an ___ comparison on a non-key, multiple records can be fetched using a primary key.
- Equality
- Duality
- Non-equality
- Non-duality
Answer: A) Equality
Explanation:
When the selection criteria specify an equality comparison on a non-key, multiple records can be fetched using a primary key.
Discuss this Question
15. ____ indexes can be used for selections with equality conditions.
- Primary
- Secondary
- Tertiary
- None
Answer: B) Secondary
Explanation:
Secondary indexes can be used for selections with equality conditions.
Discuss this Question
16. When the equality condition is met on the key, or multiple records when it is met on the nonkey, we can retrieve a single record from the ___ index strategy.
- Primary
- Secondary
- Tertiary
- None
Answer: B) Secondary
Explanation:
When the equality condition is met on the key, or multiple records when it is met on the nonkey, we can retrieve a single record from the secondary index strategy.
Discuss this Question
17. A single record can be retrieved for the same time as the ___ index.
- Primary
- Secondary
- Tertiary
- None
Answer: A) Primary
Explanation:
A single record can be retrieved for the same time as the primary index.
Discuss this Question
18. Using ___ can be used to make selections based on comparisons in a relation.
- Linear Search
- Indices
- Both A and B
- None of the above
Answer: C) Both A and B
Explanation:
Using linear search or indices can be used to make selections based on comparisons in a relation.
Discuss this Question
19. An ordered primary index, such as an index from the primary __ tree, is used when the selection condition is a comparison.
- B
- B+
- B++
- None
Answer: B) B+
Explanation:
An ordered primary index, such as an index from the primary B+ tree, is used when the selection condition is a comparison.
Discuss this Question
20. File scans start searching from the very beginning until the very end and output all ___ that meet the given selection criteria.
- Attributes
- Tuples
- Columns
- None
Answer: B) Tuples
Explanation:
File scans start searching from the very beginning until the very end and output all tuples that meet the given selection criteria.
Discuss this Question
21. In the case of Secondary Index, comparison, the files scan scans the blocks of the lowest-level index to satisfy the selection operation involving the characters ____, or >=.
- <
- >
- <=
- All of the above
Answer: D) All of the above
Explanation:
In the case of Secondary Index, comparison, the files scan scans the blocks of the lowest-level index to satisfy the selection operation involving the characters <, >, <=, or >=.
Discuss this Question
22. In general, only a few records should be selected from the ___ index.
- Primary
- Secondary
- Tertiary
- None
Answer: B) Secondary
Explanation:
In general, only a few records should be selected from the secondary index.
Discuss this Question
23. By providing ___ to each record, an index facilitates the retrieval of a record by the users.
- Logs
- Arrays
- Pointers
- None
Answer: C) Pointers
Explanation:
By providing pointers to each record, an index facilitates the retrieval of a record by the users.
Discuss this Question
24. ___ may need to be retrieved from different blocks in the files, so I/O operations may be required.
- Files
- Records
- Databases
- Tables
Answer: B) Records
Explanation:
Records may need to be retrieved from different blocks in the files, so I/O operations may be required.
Discuss this Question
25. The secondary index becomes ___ if there are many records to fetch.
- Cheap
- Expensive
- Not costly
- None
Answer: B) Expensive
Explanation:
The secondary index becomes expensive if there are many records to fetch.
Discuss this Question
26. The ___ selection predicates are used when working on a complex selection.
- Conjunction
- Disjunction
- Negation
- All of the above
Answer: D) All of the above
Explanation:
The Conjunction, Disjunction, and Negation selection predicates are used when working on a complex selection.
Discuss this Question
27. ____ occur when records that satisfy the above selection condition cross.
- Conjunction
- Disjunction
- Negation
- None of the above
Answer: A) Conjunction
Explanation:
Conjunctions occur when records that satisfy the above selection condition cross.
Discuss this Question
28. ___ are a union of all records which satisfy the given conditions.
- Conjunction
- Disjunction
- Negation
- None of the above
Answer: B) Disjunction
Explanation:
Disjunctions are a union of all records which satisfy the given conditions.
Discuss this Question
29. Each ____ in the block appears together in the block, so we can retrieve all selected records of the block with a single I/O operation.
- Pointer
- Array
- Stack
- Queue
Answer: A) Pointer
Explanation:
Each pointer in the block appears together in the block, so we can retrieve all selected records of the block with a single I/O operation.
Discuss this Question