Practice Test
True/False: Data profiling is an essential process for data quality improvement.
- True
- False
Answer: True
Explanation: Data profiling measures and monitors data quality, doing this by collecting statistics and metadata information to help ensure that all data is fit for its intended use.
Multiple Select: Which of the following are considered data profiling techniques?
- A. Frequency Analysis
- B. Pattern Matching
- C. Data Preview
- D. Data Classification
Answer: A, B, C
Explanation: Frequency Analysis is checking how frequently data values occur, Pattern Matching tests data against established patterns to ensure it fits the format it’s supposed to, and Data Preview provides a snapshot of the data to check its quality.
Single Select: Which AWS service is most commonly used for data profiling?
- A. AWS Redshift
- B. AWS Glue
- C. AWS Athena
- D. AWS S3
Answer: B. AWS Glue
Explanation: AWS Glue discovers and stores associated metadata (like table definitions and schema) in the AWS Glue Data Catalog. It can perform data profiling exercises.
True/False: Data profiling is only necessary if you’re dealing with large volumes of data.
- True
- False
Answer: False
Explanation: Data profiling is beneficial for any amount of data, no matter how large or small. Even relatively small datasets can have inconsistencies or issues that should be addressed.
Multiple Select: What information can data profiling provide about your data?
- A. Range of values
- B. Frequency of values
- C. Pattern inconsistencies
- D. All of the above
Answer: D. All of the above
Explanation: A thorough data profiling process can provide a wide range of information about data, including range, frequency, and pattern inconsistencies.
Single Select: Data profiling can help in
- A. Cleaning data
- B. Visualizing data
- C. Improving data
- D. All of the above
Answer: D. All of the above
Explanation: Data profiling helps in cleaning, visualizing, and improving data by identifying errors, inconsistencies, and redundancies in the data.
True/False: Data profiling does not help in data migration process.
- True
- False
Answer: False
Explanation: Data profiling can assist in the data migration process by ensuring that only high-quality, relevant data is transferred.
Multiple Select: What are the benefits of data profiling?
- A. Improved data quality
- B. Reduced data redundancy
- C. Enhanced data security
- D. None of the above
Answer: A, B, C
Explanation: Data profiling significantly improves data quality, reduces redundancy, and can enhance security because it helps professionals to understand and manage the data better.
Single Select: In AWS, data profiling tasks run on
- A. AWS Glue
- B. AWS Data Pipeline
- C. AWS DMS
- D. AWS Athena
Answer: A. AWS Glue
Explanation: AWS Glue is used for running data profiling tasks as it collects the metadata information which helps in profiling tasks.
True/False: AWS Glue supports data profiling for both semi-structured and structured data types.
- True
- False
Answer: True
Explanation: AWS Glue supports data profiling for both semi-structured (like JSON and XML) and structured (like CSV and JDBC data sources) data types.
Interview Questions
What is data profiling in the context of AWS Big Data?
Data profiling is the process of assessing and understanding your data by using statistical analysis and assessment methods. It includes inspecting, cleaning and transforming data to discover useful information, suggest conclusions, and support decision-making.
What AWS tool can assist in data profiling tasks?
AWS Glue is a fully managed extract, transform, and load (ETL) service that can assist in data profiling tasks by categorizing, organizing and making data searchable.
What is the purpose of Data Catalog in AWS Glue?
The AWS Glue Data Catalog is a fully managed, Apache Hive Metastore compatible, metadata repository. It serves as a centralized store, containing table definitions, job definitions and other control information to manage your AWS Glue environments.
Which AWS service is designed to prepare and load real-time data for analytics?
Amazon Kinesis is designed to prepare and load real-time data for analytics.
What are the benefits of using AWS Glue for data profiling?
Some benefits include the automated discovery of schema and metadata, the ability to create ETL jobs with code generation, visual data pipeline orchestration and a unified data catalog.
What services of AWS are more suitable for storing structured data?
For storing structured data, Amazon RDS, Amazon DynamoDB, and Amazon Redshift are more suitable.
What is an AWS data lake?
AWS data lake is a centralized repository allowing you to store all your structured and unstructured data at any scale. With AWS data lake, you can analyze your data with different analytics and machine learning tools, as needed.
Why would you use Amazon Redshift Spectrum in a big data environment?
Amazon Redshift Spectrum is an Amazon Redshift feature that allows you to run queries against exabytes of data in Amazon S3 without having to load or transform any data.
Can you use AWS Glue with streaming data?
No, AWS Glue doesn’t natively support streaming data. For real-time streaming data, consider using Amazon Kinesis.
What AWS service can be used for quick ad hoc data profiling and analysis?
Amazon Athena can be used for quick ad hoc data profiling, analysis, and exploration. Athena is server-less and allows SQL queries directly against data stored in S3.
How does AWS Glue discover schema?
AWS Glue automatically generates the schema of your data when it runs a crawler to access your data source.
Which AWS tool helps with automated data cataloging?
AWS Glue provides automated data cataloging.
Which AWS services can integrate with AWS Glue for data transformation tasks?
Amazon Redshift, Amazon S3, Amazon RDS, and Amazon DynamoDB can integrate with AWS Glue for data transformation tasks.
Which AWS service would you use for real-time analysis of streaming data?
The Amazon Kinesis suite of tools, especially Kinesis Analytics, are optimal for real-time analysis of streaming data.
Is AWS Glue compatible with Apache Spark and Python?
Yes, AWS Glue is compatible with both Apache Spark and Python. It generates ETL code in Python and Scala which can be further customized using familiar programming languages.
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