Database Management System MCQs with Answers
Practice important Database Management System MCQs with answers and explanations.
Chapter: 38
Q621:
What does a clustered index determine in a database table?
A. The physical storage order of data
B. The logical order of data
C. The index key value for data
D. The total number of records
Correct Answer:
A
Chapter: 38
Q622:
A secondary index must contain pointers to:
A. Only the first record with each search-key value
B. All records with the same search-key value
C. Records with unique search-key values
D. Records with non-unique search-key values
Correct Answer:
B
Chapter: 38
Q623:
What is true about non-clustered indexes compared to clustered indexes?
A. Non-clustered indexes store the data rows in order based on their key values
B. Non-clustered indexes do not affect the physical storage order of data
C. Non-clustered indexes are automatically created by PRIMARY KEY constraints
D. Non-clustered indexes are created to speed up sequential scans
Correct Answer:
B
Chapter: 38
Q624:
Dense indices generally:
A. Require less space and maintenance than sparse indices
B. Contain an index record for every search key value in the file
C. Are faster in general than sparse indices
D. Are used only for non-primary key attributes
Correct Answer:
B
Chapter: 38
Q625:
A composite index:
A. Can only be created on a single field
B. Uses multiple fields as the search key
C. Can only be used for range queries
D. Stores data entries based on a single field
Correct Answer:
B
Chapter: 38
Q626:
Which of the following is NOT a property of indexes?
A. Indexes can be created without data in the table
B. Indexes support equality selections
C. Indexes are always ordered by the search key value
D. Indexes cannot be updated without affecting the base tables
Correct Answer:
C
Chapter: 38
Q627:
The purpose of a primary index is to:
A. Provide a sorted order based on a secondary attribute
B. Store data in random order for faster access
C. Organize data in the table based on the primary key attribute
D. Allow fast access to data based on a non-primary key attribute
Correct Answer:
C
Chapter: 38
Q628:
Sparse indices:
A. Have an index record for every search key value
B. Require more space than dense indices
C. Are typically used to save space and reduce maintenance
D. Provide faster access than dense indices in all cases
Correct Answer:
C
Chapter: 38
Q629:
What must be updated whenever a record is inserted or deleted from a file?
A. The index associated with the file
B. Only the file itself
C. Only the data records
D. No updates are necessary
Correct Answer:
A
Chapter: 38
Q630:
A clustered index can be created on:
A. Only one column
B. Multiple columns
C. A combination of columns or a single column
D. Only columns that are part of the PRIMARY KEY
Correct Answer:
C
Chapter: 38
Q631:
Fill in the blank: A __________ index is used to store the address of every tuple in the table for non-primary key attributes.
A. Primary
B. Sparse
C. Secondary
D. Dense
Correct Answer:
C
Chapter: 38
Q632:
The search key of a primary index is:
A. The only index key used in the file
B. The key that specifies the sequential order of the file
C. The key that is used to find non-clustered index rows
D. The key that points to all records with a specific search key value
Correct Answer:
B
Chapter: 38
Q633:
Fill in the blank: __________ indices are faster in general because they contain an index record for every search key value.
A. Sparse
B. Dense
C. Primary
D. Secondary
Correct Answer:
B
Chapter: 38
Q634:
Which type of index is automatically created by PRIMARY KEY constraints?
A. Clustered Index
B. Non-clustered Index
C. Sparse Index
D. Dense Index
Correct Answer:
A
Chapter: 38
Q635:
Fill in the blank: Non-clustered indexes in SQL Server 7.0 use __________ as row locators if the table has a clustered index.
A. File ID
B. Page number
C. Clustered index key
D. Row ID
Correct Answer:
C
Chapter: 39
Q636:
What is the main purpose of using views in a database?
A. To increase data redundancy
B. To simplify data access and security
C. To replace indexes
D. To speed up data insertion
Correct Answer:
B
Chapter: 39
Q637:
A view in a database is essentially a _______.
A. Physical table
B. A virtual table
C. Temporary storage
D. Backup file
Correct Answer:
B
Chapter: 39
Q638:
Which type of view is a replica of a target master from a single point in time?
A. Complex View
B. Simple View
C. Dynamic View
D. Materialized View
Correct Answer:
D
Chapter: 39
Q639:
Dynamic views in databases are updated _______.
A. Periodically, not necessarily on access
B. Only when the database is updated
C. Every time they are accessed
D. Once a day
Correct Answer:
C
Chapter: 39
Q640:
A clustered index in a table can be created on _______.
A. Only one column
B. A combination of columns
C. Any column regardless of uniqueness
D. A view of the table
Correct Answer:
B