Database Performance Tuning: Master Query Optimization and Bottleneck Reduction

Question 1

For a data warehouse with high data volume and complex analytical queries, which query optimization technique is most suitable?

Accepted Answer

Cost-based optimization

Answer

Rule-based optimization

Answer

Heuristic optimization

Answer

Genetic optimization

Question 2

Which of the following factors does NOT directly impact database performance?

Accepted Answer

End-user experience

Answer

Hardware specifications

Answer

Data volume

Answer

Query complexity

Question 3

What is the primary function of a SQL optimizer in database performance tuning?

Accepted Answer

Generating efficient query execution plans

Answer

Identifying inefficient queries

Answer

Monitoring database performance metrics

Answer

Tuning database configuration parameters

Question 4

Which of the following techniques is used to minimize the number of database connections?

Accepted Answer

Connection pooling

Answer

Database sharding

Answer

Data caching

Answer

Query parallelization

Question 5

What is the main purpose of query caching in database performance tuning?

Accepted Answer

Storing frequently executed queries to reduce execution time

Answer

Reducing query parsing overhead

Answer

Improving data consistency

Answer

Preventing SQL injection attacks

Question 6

What is a potential disadvantage of horizontal data partitioning?

Accepted Answer

Complex query processing

Answer

Increased data redundancy

Answer

Limited scalability

Answer

Reduced data security

Question 7

What is the primary goal of database query optimization?

Accepted Answer

To transform database queries into more efficient forms to enhance performance

Answer

To create new indexes to accelerate query execution

Answer

To monitor query execution plans for performance analysis

Answer

To detect and identify slow-running queries

Question 8

Explain the distinction between logical and physical database design.

Accepted Answer

Logical design focuses on data representation and relationships, while physical design focuses on data storage implementation.

Answer

Physical design focuses on data representation and relationships, while logical design focuses on data storage implementation.

Answer

They represent the same concept with different names.

Answer

Logical design utilizes tables, while physical design employs entities.

Question 9

What is the primary purpose of referential integrity in database systems?

Accepted Answer

To maintain data consistency by enforcing relationships between tables

Answer

To prevent data loss during database updates and modifications

Answer

To enhance database performance by optimizing data access

Answer

To establish relationships between different database tables

Question 10

Describe the difference between a primary key and a foreign key in a database table.

Accepted Answer

A primary key uniquely identifies each row in a table, while a foreign key references a primary key in another table.

Answer

A foreign key uniquely identifies each row in a table, while a primary key references a foreign key in another table.

Answer

They represent the same concept with different names.

Answer

A primary key is used for sorting data, while a foreign key is used for joining tables.

Question 11

Which indexing technique is most suitable for range queries on a large table with a clustered index to optimize query performance?

Accepted Answer

B-tree index

Answer

Hash index

Answer

Bitmap index

Answer

Full-text index

Question 12

What is the primary goal of database performance tuning?

Accepted Answer

Optimizing query speed and minimizing resource consumption

Answer

Increasing data accuracy and integrity

Answer

Enhancing security and data protection

Answer

Improving user experience and satisfaction

Question 13

What is the purpose of a cardinality estimator in database optimization?

Accepted Answer

Estimating the number of rows returned by a query to optimize execution plans

Answer

Optimizing the order of join operations

Answer

Estimating the cost of executing a query

Answer

Identifying duplicate rows

Question 14

What is the difference between a compiled and an interpreted database query execution plan?

Accepted Answer

A compiled plan is stored in the database and reused, while an interpreted plan is generated on the fly

Answer

An interpreted plan is more efficient than a compiled plan

Answer

Compiled plans are only used for highly optimized queries

Answer

Interpreted plans can be optimized on the fly

Question 15

What is the concept of 'star schema' in database design?

Accepted Answer

A type of data warehouse schema designed for efficient data retrieval and aggregation, where fact tables are joined to dimension tables

Answer

A schema used to represent hierarchical data structures

Answer

A schema that ensures data integrity and referential constraints

Answer

A schema that optimizes query performance in real-time systems

Question 16

Which index type is ideal for range queries, allowing efficient retrieval of data within a specified range?

Accepted Answer

B-tree index

Answer

Hash index

Answer

Bitmap index

Answer

GIST index

Question 17

Which technique is employed to minimize the number of I/O operations in a database, thereby enhancing performance?

Accepted Answer

Clustering related data physically on the storage device

Answer

Creating indexes to expedite data retrieval

Answer

Normalizing data to eliminate redundancy

Answer

Denormalizing data for faster access

Question 18

What is the primary responsibility of a database optimizer?

Accepted Answer

Generating efficient query execution plans to minimize resource consumption

Answer

Tuning database configuration parameters for optimal performance

Answer

Creating database indexes to accelerate data retrieval

Answer

Monitoring database performance and identifying potential bottlenecks

Question 19

What is a key advantage of employing a NoSQL database for handling high-volume data applications?

Accepted Answer

Exceptional scalability to accommodate growing data volumes

Answer

Uncompromising consistency, ensuring data integrity

Answer

Robust data integrity mechanisms to prevent data corruption

Answer

Comprehensive transaction support for complex data operations

Question 20

In evaluating the effectiveness of a database performance tuning solution, which metric is paramount?

Accepted Answer

Average query response time

Answer

Queries executed per second

Answer

CPU utilization of the database server

Answer

Memory consumption of the database server

Question 21

Which technique is primarily used to enhance query performance, rather than optimizing the query itself?

Accepted Answer

Bitmap index creation

Answer

Cost-based optimization

Answer

Rule-based optimization

Answer

Query rewriting

Question 22

What is a key advantage of utilizing indexes?

Accepted Answer

Accelerated data retrieval

Answer

Reduced data storage requirements

Answer

Improved data integrity

Answer

Increased security measures

Question 23

What is the function of a database buffer pool?

Accepted Answer

Storing frequently accessed data in memory

Answer

Caching query outcomes

Answer

Managing database transactions

Answer

Optimizing query execution plans

Question 24

Which metric is commonly used to assess database performance?

Accepted Answer

Query execution duration

Answer

Database size

Answer

Concurrent user count

Answer

Disk space utilization

Question 25

What is the purpose of a database performance tuning advisor?

Accepted Answer

Providing recommendations to enhance database performance

Answer

Identifying and resolving specific performance issues

Answer

Automating database maintenance tasks

Answer

Monitoring database activities

Question 26

Which of the following is NOT a best practice for database performance tuning?

Accepted Answer

Excessive index creation

Answer

Regular monitoring of database performance metrics

Answer

Optimizing queries for enhanced execution speed

Answer

Using appropriate data types

Question 27

What is the primary objective of database performance tuning?

Accepted Answer

To minimize query response time and improve overall database efficiency

Answer

To ensure data integrity

Question 28

What is the primary purpose of using histograms in database performance tuning?

Accepted Answer

To analyze data distribution and frequency for a particular column, aiding in query optimization

Answer

To store temporary data for faster query processing

Question 29

What is a potential disadvantage of denormalizing a database?

Accepted Answer

Increased data redundancy, which may lead to data inconsistencies if not managed properly

Answer

Reduced data consistency

Question 30

What is the primary benefit of partitioning a large table in a database?

Accepted Answer

Improved query performance by dividing data into smaller, more manageable chunks

Answer

To reduce data storage requirements

Question 31

For a large table with a frequently queried column, which index type is most suitable to improve retrieval efficiency?

Accepted Answer

Clustered index

Answer

Non-clustered index

Answer

Hash index

Question 32

Which index structure is most suitable for range queries?

Accepted Answer

B-tree

Answer

Hash index

Answer

Bitmap index

Answer

R-tree

Question 33

Which of the following is a commonly used metric for measuring database performance?

Accepted Answer

Query execution time

Answer

Database size

Answer

Number of users

Answer

Disk space utilization

Question 34

What is the effect of denormalization on data integrity?

Accepted Answer

It compromises data integrity

Answer

It enhances data integrity

Answer

It has no impact on data integrity

Answer

It depends on the denormalization technique employed

Question 35

Which of the following is an advantage of using caching in database systems?

Accepted Answer

Reduced query execution time

Answer

Improved data consistency

Answer

Increased database security

Answer

Reduced database load

Question 36

How do clustered indexes differ from non-clustered indexes?

Accepted Answer

Clustered indexes physically organize data based on the index key, while non-clustered indexes do not.

Answer

Non-clustered indexes physically organize data based on the index key, while clustered indexes do not.

Answer

Clustered indexes allow multiple indexes per table, while non-clustered indexes allow only one index.

Answer

Non-clustered indexes allow multiple indexes per table, while clustered indexes allow only one index.

Question 37

Which of the following is a common query optimization technique used to enhance database performance?

Accepted Answer

Create indexes on frequently accessed table columns

Answer

Rewrite the query using a less efficient algorithm

Answer

Denormalize the database structure

Answer

Increase the size of the database buffer cache

Question 38

Database normalization primarily aims to:

Accepted Answer

Reduce data redundancy and ensure data integrity

Answer

Simplify database management tasks

Answer

Enhance query execution speed

Question 39

The fundamental goal of database performance tuning is to:

Accepted Answer

Optimize database operations and minimize response times

Answer

Maximize the storage capacity of the database

Answer

Eliminate all potential errors within the database

Question 40

Database indexes are primarily designed to:

Accepted Answer

Accelerate data retrieval by providing direct access to specific rows

Answer

Guarantee data integrity

Answer

Minimize data redundancy

Question 41

What is the key distinction between a clustered and a non-clustered index?

Accepted Answer

A clustered index physically organizes the table data based on the index key, whereas a non-clustered index creates a separate structure to store index information.

Answer

Clustered indexes are always faster than non-clustered indexes.

Question 42

Which of the following is a key advantage of utilizing a database management system (DBMS)?

Accepted Answer

Centralized data management and enhanced security

Answer

Increased data redundancy

Answer

Reduced data integrity

Answer

Potentially higher development costs

Question 43

The primary objective of database transaction management is to ensure:

Accepted Answer

Atomicity, consistency, isolation, and durability (ACID) properties of database transactions

Answer

Improved query performance

Question 44

What is the primary purpose of creating an index on a database table?

Accepted Answer

To speed up data retrieval by providing a quick lookup mechanism.

Answer

To enable the aggregation of data within the table.

Answer

To reduce the amount of physical storage space used by the table.

Answer

To ensure data integrity by enforcing constraints.

Question 45

What is the main goal of query tuning?

Accepted Answer

To optimize query execution efficiency, reducing the time it takes to retrieve results.

Answer

To facilitate data analysis by providing tools for summarizing and exploring data.

Answer

To minimize the size of the database by removing redundant data.

Answer

To enhance data security by restricting access to sensitive information.

Question 46

Which of the following metrics is commonly used to measure query performance?

Accepted Answer

Execution time

Answer

Disk space consumed by the database.

Answer

Amount of memory used by the database during query execution.

Answer

Network bandwidth used during data transfer.

Question 47

Which of the following is a best practice for database performance tuning?

Accepted Answer

Regularly review and tune indexes to ensure they remain efficient and relevant.

Answer

Avoid using performance monitoring tools as they can negatively impact performance.

Answer

Ignore performance issues until they become critical and significantly impact system operations.

Answer

Increase the database size indefinitely, assuming more storage space always equates to better performance.

Question 48

What is the potential negative impact of poorly designed queries on database performance?

Accepted Answer

Increased resource consumption, such as CPU and memory utilization, leading to performance degradation and potential system slowdowns.

Answer

Improved data consistency, leading to more reliable and accurate data.

Answer

Reduced storage requirements, making the database more efficient in terms of space usage.

Question 49

Which of the following tools can be effectively used to pinpoint performance bottlenecks in database operations?

Accepted Answer

Query profiler

Answer

Text editor, which is primarily used for editing code and not performance analysis.

Answer

Database management system (DBMS), while providing performance metrics, may not offer detailed insights into bottlenecks.

Answer

Spreadsheet application, which is designed for data manipulation and not performance profiling.

Question 50

Which of the following is NOT a primary approach to database performance tuning?

Accepted Answer

Adding more data to a table

Answer

Optimizing queries

Answer

Indexing tables

Answer

Normalizing data

Question 51

What is a primary benefit of indexing a column in a table?

Accepted Answer

Faster data retrieval

Answer

Reduced storage space

Answer

Improved data accuracy

Question 52

Which query optimization technique reduces the number of rows returned by a query?

Accepted Answer

Predicate filtering

Answer

Index utilization

Answer

Query caching

Answer

Join optimization

Question 53

What is the purpose of query caching in database performance tuning?

Accepted Answer

Storing frequently executed queries in memory to reduce execution times

Answer

Preventing data loss in case of hardware failure

Answer

Maintaining data integrity

Question 54

What is the primary goal of database schema tuning?

Accepted Answer

Optimizing database efficiency and maintainability

Answer

Enhancing data security

Answer

Reducing data storage requirements

Question 55

Which of the following is a critical metric for measuring database performance?

Accepted Answer

Query execution time

Answer

Number of database users

Answer

Number of database transactions

Answer

Size of database tables

Question 56

Describe the consequences of database fragmentation and how it can affect performance.

Accepted Answer

Database fragmentation occurs when data is scattered across multiple storage units, leading to slower data retrieval.

Answer

Database fragmentation improves data security