What is the purpose of outlier detection in data cleansing?

  • To fill missing values in the dataset
  • To identify and remove data points that deviate significantly from the rest of the dataset
  • To merge duplicate records in the dataset
  • To standardize the format of the dataset
Outlier detection in data cleansing aims to identify and remove data points that deviate significantly from the rest of the dataset. Outliers can skew statistical analyses and machine learning models, leading to inaccurate results or biased predictions. Detecting and addressing outliers helps improve the quality and reliability of the dataset for downstream analysis and modeling tasks.

How does metadata management facilitate data governance through data lineage?

  • Automating data classification
  • Enforcing data quality standards
  • Implementing access controls
  • Providing visibility into data origins and transformations
Metadata management plays a vital role in facilitating data governance through data lineage by providing visibility into data origins and transformations. By documenting the flow of data from its source to its destination and capturing metadata about each step, organizations can understand how data is used, manipulated, and transformed across different processes. This visibility enables stakeholders to assess data quality, identify potential issues, and ensure compliance with regulatory requirements. Moreover, metadata management supports data lineage by linking data assets to business glossaries, policies, and standards, thereby enhancing data governance practices.

Which of the following is a common technique used for data extraction in the ETL process?

  • Change Data Capture (CDC)
  • Data aggregation
  • Data normalization
  • Data validation
Change Data Capture (CDC) is a common technique in the ETL (Extract, Transform, Load) process. It captures changes made to data in the source systems and reflects them in the target system, ensuring data consistency.

________ is a technique used in ETL optimization to distribute data processing across multiple nodes or servers.

  • Parallelization
  • Partitioning
  • Replication
  • Sharding
Parallelization is a technique used in ETL (Extract, Transform, Load) optimization to distribute data processing across multiple nodes or servers. It involves dividing the workload among multiple processors to improve efficiency and reduce processing time.

________ is the ability of a real-time data processing system to handle high volumes of data with minimal delay.

  • Efficiency
  • Latency
  • Scalability
  • Throughput
Scalability is the ability of a real-time data processing system to handle high volumes of data with minimal delay. Scalable systems can efficiently process increasing data loads by distributing workloads across multiple resources or nodes, thereby maintaining performance and responsiveness. This is crucial for handling growing data volumes and maintaining system performance under varying workloads.

How does fault tolerance play a role in real-time data processing systems?

  • It ensures systems continue operating even in the presence of hardware or software failures
  • It optimizes the processing speed of real-time systems
  • It provides enhanced security for data in transit
  • It reduces the need for scalability in data processing systems
Fault tolerance plays a crucial role in real-time data processing systems by ensuring uninterrupted operation despite hardware or software failures. This is achieved through mechanisms such as replication, redundancy, and failover strategies. By maintaining system availability and data integrity, fault tolerance enables real-time systems to handle failures gracefully, minimizing downtime and ensuring reliable data processing.

Scenario: Your team is developing a data pipeline for processing real-time customer transactions. However, intermittent network issues occasionally cause task failures. How would you design an effective error handling and retry mechanism to ensure data integrity?

  • Implement a circuit-breaking mechanism
  • Implement exponential backoff with jitter
  • Retry tasks with fixed intervals
  • Utilize a dead-letter queue for failed tasks
Implementing exponential backoff with jitter is a robust strategy for handling errors in a data pipeline. This approach gradually increases the time between retry attempts, reducing the load on the system during transient failures. Adding jitter introduces randomness to the retry intervals, preventing synchronization of retry attempts and reducing the likelihood of overwhelming the system when issues persist.

The SQL command used to permanently remove a table from the database is ________.

  • DELETE TABLE
  • DESTROY TABLE
  • DROP TABLE
  • REMOVE TABLE
The DROP TABLE command is used in SQL to permanently remove a table and all its data from the database. It's important to exercise caution when using this command as it cannot be undone.

What strategies can be employed to ensure scalability in data modeling projects?

  • Consistent use of primary keys
  • Implementation of complex queries
  • Normalization and denormalization
  • Vertical and horizontal partitioning
Strategies such as vertical and horizontal partitioning allow for distributing data across multiple resources, ensuring scalability by accommodating growing data volumes and supporting efficient data retrieval.

What are some potential drawbacks of over-indexing a database?

  • Enhanced data consistency
  • Improved query performance
  • Increased storage space and maintenance overhead
  • Reduced likelihood of index fragmentation
Over-indexing a database can lead to increased storage space and maintenance overhead. It may also slow down data modification operations and increase the likelihood of index fragmentation, affecting overall performance.

Scenario: You're working on a project where data consistency is critical, and the system needs to handle rapid scaling. How would you address these requirements using NoSQL databases?

  • Combine multiple NoSQL databases
  • Implement eventual consistency
  • Use a database with strong consistency model
  • Utilize sharding and replication for scaling
In a project where data consistency is critical and rapid scaling is required, using a NoSQL database with a strong consistency model ensures data integrity. This may involve sacrificing some scalability for consistency.

The process of assessing the quality of data and identifying potential issues is known as ________.

  • Data governance
  • Data profiling
  • Data stewardship
  • Data validation
Data profiling involves analyzing and examining the characteristics and quality of data to understand its structure, content, and potential issues. It includes tasks such as assessing data completeness, consistency, accuracy, and integrity to identify anomalies, patterns, and outliers. Data profiling helps organizations gain insights into their data assets, prioritize data quality improvements, and make informed decisions regarding data management strategies and processes.