DBMS Indexing MCQs

DBMS Indexing MCQs: This section contains multiple-choice questions and answers on Indexing in DBMS.
Submitted by Anushree Goswami, on April 23, 2022

1. A database is ___ to reduce the number of disk accesses needed to process queries in order to improve performance.

  1. Non-indexed
  2. Indexed
  3. Inserted
  4. Updated

Answer: B) Indexed

Explanation:

A database is indexed to reduce the number of disk accesses needed to process queries in order to improve performance.

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2. What is index?

  1. Type of Dataset
  2. Type of Database
  3. Type of Record
  4. Type of Data Structure

Answer: D) Type of Data Structure

Explanation:

Index is the type of data structure.

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3. A database ___ can be quickly accessed and located with it.

  1. Row
  2. Column
  3. Table
  4. Field

Answer: C) Table

Explanation:

A database table can be quickly accessed and located with it.

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4. Some database columns can be used to create ___.

  1. Indices
  2. Files
  3. Indexes
  4. Records

Answer: C) Indexes

Explanation:

Some database columns can be used to create indexes.

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5. How many columns are there in Structure of Index?

  1. 2
  2. 3
  3. 4
  4. 5

Answer: A) 2

Explanation:

There are 2 columns in the Structure of Index.

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6. Which of the following is the column in structure of index?

  1. Search Key
  2. Data Reference
  3. Both A and B
  4. None of the above

Answer: C) Both A and B

Explanation:

The columns in the structure of index are -

  1. Search Key
  2. Data Reference

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7. A copy of the ___ of the table is in the first column of the database, i.e., search key.

  1. Primary Key
  2. Candidate Key
  3. Both A and B
  4. None of the above

Answer: C) Both A and B

Explanation:

A copy of the primary key or candidate key of the table is in the first column of the database.

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8. A ___ key is sorted in order to make it easy to access data corresponding to it.

  1. Primary
  2. Foreign
  3. Composite
  4. Alternate

Answer: A) Primary

Explanation:

A primary key is sorted in order to make it easy to access data corresponding to it.

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9. ___ are found in the second column of the database.

  1. Datasets
  2. Data structure
  3. Data references
  4. Data items

Answer: C) Data references

Explanation:

Data references are found in the second column of the database.

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10. Each ___ consists of a set of pointers containing the address of the disk block containing the value for that ___.

  1. Dataset
  2. Data Item
  3. Key
  4. Log

Answer: C) Key

Explanation:

Each key consists of a set of pointers containing the address of the disk block containing the value for that key.

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11. How many indexing methods are there?

  1. 3
  2. 4
  3. 5
  4. 6

Answer: B) 4

Explanation:

There are 4 indexing methods.

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12. Which of the following is an indexing method?

  1. Primary
  2. Clustering
  3. Secondary
  4. All of the above

Answer: D) All of the above

Explanation:

The indexing methods are -

  1. Ordered
  2. Primary
  3. Clustering
  4. Secondary

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13. How many types of primary index are there?

  1. 2
  2. 3
  3. 4
  4. 5

Answer: A) 2

Explanation:

There are 2 types of primary index.

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14. Which of the following is the type of primary index?

  1. Dense Index
  2. Spare Index
  3. Both A and B
  4. None of the above

Answer: C) Both A and B

Explanation:

The type of primary index are -

  1. Dense Index
  2. Spare Index

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15. Searches are usually made ___ by sorting the indices.

  1. Slower
  2. Dimmer
  3. Faster
  4. Stopped

Answer: C) Faster

Explanation:

Searches are usually made faster by sorting the indices.

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16. Indexes that are ordered are referred to as ___ indices.

  1. Ordered
  2. Primary
  3. Clustering
  4. Secondary

Answer: A) Ordered

Explanation:

Indexes that are ordered are referred to as ordered indices.

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17. It is known as primary indexing if the index is created based on the table's primary key.

  1. Primary
  2. Foreign
  3. Alternate
  4. Composite

Answer: A) Primary

Explanation:

It is known as primary indexing if the index is created based on the table's primary key.

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18. Records containing these primary keys are uniquely identified by these keys and have a ___ relationship between them.

  1. 1:1
  2. 1:M
  3. M:1
  4. M:M

Answer: A) 1:1

Explanation:

Records containing these primary keys are uniquely identified by these keys and have a 1:1 relationship between them.

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19. Since primary keys are sorted, ___ operations are quite efficient because of their sorted order.

  1. Add
  2. Update
  3. Search
  4. Delete

Answer: C) Search

Explanation:

Since primary keys are sorted, search operations are quite efficient because of their sorted order.

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20. Each search key value in the data file has an index record in the ___ index.

  1. Sparse
  2. Dense
  3. Both A and B
  4. None of the above

Answer: B) Dense

Explanation:

Each search key value in the data file has an index record in the dense index.

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21. There is no difference in the number of ___ in the index and main tables when using Dense Index.

  1. Files
  2. Databases
  3. Records
  4. Datasets

Answer: C) Records

Explanation:

There is no difference in the number of records in the index and main tables when using Dense Index.

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22. The index record itself takes up ___ space in a dense index.

  1. Less
  2. Little
  3. Few
  4. More

Answer: D) More

Explanation:

The index record itself takes up more space in a dense index.

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23. Which of the following is the type of primary index?

  1. Dense Index
  2. Spare Index
  3. Both A and B
  4. None of the above

Answer: C) Both A and B

Explanation:

The type of primary index are -

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24. Besides the search key, index records contain a pointer to the ___ data on the disk.

  1. Previous
  2. Consecutive
  3. Actual
  4. None

Answer: C) Actual

Explanation:

Besides the search key, index records contain a pointer to the actual data on the disk.

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25. ___ index records appear only for a few items in the data file.

  1. Dense
  2. Sparse
  3. Both A and B
  4. None of the above

Answer: B) Sparse

Explanation:

Sparse index records appear only for a few items in the data file.

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26. Sparse index items point to ___.

  1. Files
  2. Records
  3. Blocks
  4. None

Answer: C) Blocks

Explanation:

Sparse index items point to blocks.

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27. An index that points to the records in a ___ in the main table rather than each record in the main table is a sparse index.

  1. Filled Space
  2. Gap
  3. Files
  4. Records

Answer: B) Gap

Explanation:

An index that points to the records in a gap in the main table rather than each record in the main table is a sparse index.

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28. An ordered data file can be considered a ___ index.

  1. Primary
  2. Dense
  3. Sparse
  4. Clustered

Answer: D) Clustered

Explanation:

An ordered data file can be considered a clustered index.

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29. The index can be built on columns other than ___ keys, which are not guaranteed to be unique.

  1. Primary
  2. Foreign
  3. Composite
  4. Alternate

Answer: A) Primary

Explanation:

The index can be built on columns other than primary keys, which are not guaranteed to be unique.

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30. Clustering can be used to identify records faster by grouping ___ columns to get the unique value and creating an index from them.

  1. One
  2. Two
  3. Two or more
  4. None

Answer: C) Two or more

Explanation:

Clustering can be used to identify records faster by grouping two or more columns to get the unique value and creating an index from them.

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31. Creating indices for these groups of records such as in clustering index is done after groups of records which have similar characteristics are ____ together.

  1. Grouped
  2. Distributed
  3. Replaced
  4. None

Answer: A) Grouped

Explanation:

Creating indices for these groups of records is done after groups of records which have similar characteristics are grouped together.

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32. In the case of creating separate disk blocks for individual clusters, that's referred to as a ___.

  1. Technique
  2. Better
  3. Better Technique
  4. Technique Better

Answer: C) Better Technique

Explanation:

In the case of creating separate disk blocks for individual clusters, that's referred to as a better technique.

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33. Whenever the size of the table increases, so does the size of the ___ in the sparse index.

  1. Table
  2. Mapping
  3. Files
  4. Adding

Answer: B) Mapping

Explanation:

Whenever the size of the table increases, so does the size of the mapping.

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34. A mapping would typically be kept in ____ memory in order to make address fetching faster.

  1. Primary
  2. Secondary
  3. Ternary
  4. None

Answer: A) Primary

Explanation:

A mapping would typically be kept in primary memory in order to make address fetching faster.

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35. Based on the ___ mapped to the secondary memory, that memory searches for the data.

  1. Address
  2. Number
  3. Name
  4. Type

Answer: A) Address

Explanation:

Based on the address mapped to the secondary memory, that memory searches for the data.

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36. Fetching the address becomes slower when the mapping size grows.

  1. Faster
  2. Super faster
  3. Slower
  4. None

Answer: C) Slower

Explanation:

Fetching the address becomes slower when the mapping size grows.

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37. When the mapping size grow which index is inefficient?

  1. Sparse
  2. Secondary
  3. Both A and B
  4. None of the above

Answer: A) Sparse

Explanation:

When the mapping size grows, the sparse index is inefficient.

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38. Adding another level of ___ to secondary ___ reduces the size of mapping.

  1. Indexing
  2. Mapping
  3. Adding
  4. Merging

Answer: A) Indexing

Explanation:

Adding another level of indexing to secondary indexing reduces the size of mapping.

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39. In the secondary index method, the large ranges of the columns are selected to begin with so that the ___ level of mapping becomes small.

  1. First
  2. Second
  3. Middle
  4. Last

Answer: A) First

Explanation:

In the secondary index method, the large ranges of the columns are selected to begin with so that the first level of mapping becomes small.

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40. As part of the secondary index method, the columns are initially selected for their huge ranges, resulting in a small first-level mapping size. After that, each range is further divided into ___ ranges.

  1. Bigger
  2. Larger
  3. Smaller
  4. Wider

Answer: C) Smaller

Explanation:

As part of the secondary index method, the columns are initially selected for their huge ranges, resulting in a small first-level mapping size. After that, each range is further divided into smaller ranges.

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41. ___-level mappings are stored in primary memory, so that accessing them is more expedient.

  1. First
  2. Second
  3. Third
  4. Last

Answer: A) First

Explanation:

First-level mappings are stored in primary memory, so that accessing them is more expedient.

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42. Both the ___ level mapping and actual data are stored on the hard disk (secondary memory).

  1. First
  2. Second
  3. Third
  4. None

Answer: B) Second

Explanation:

Both the second level mapping and actual data are stored on the hard disk (secondary memory).

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