What is the difference between data cleansing and data validation?
- Data cleansing ensures data integrity, while data validation ensures data availability.
- Data cleansing focuses on ensuring data consistency, whereas data validation focuses on data accuracy.
- Data cleansing involves correcting or removing inaccurate or incomplete data, while data validation ensures that data adheres to predefined rules or standards.
- Data cleansing involves removing duplicates, while data validation involves identifying outliers.
Data cleansing refers to the process of detecting and correcting (or removing) inaccurate or incomplete data from a dataset. It involves tasks such as removing duplicates, correcting typographical errors, filling in missing values, and standardizing formats. On the other hand, data validation ensures that data meets specific criteria or conforms to predefined rules or standards. It involves tasks such as checking data types, ranges, formats, and relationships to ensure accuracy and consistency. Both processes are crucial for maintaining high-quality data in databases and analytics systems.
Denormalization can lead to faster ________ due to reduced ________ operations.
- Indexing, Joins
- Indexing, Query
- Joins, Indexing
- Queries, Join
Denormalization can lead to faster queries due to reduced join operations. By combining data from multiple normalized tables into a single denormalized table, the need for complex joins is minimized, resulting in faster query execution times, especially for read-heavy workloads.
What are the differences between synchronous and asynchronous communication in distributed systems?
- Asynchronous communication is always faster than synchronous communication.
- In synchronous communication, the sender and receiver must be active at the same time, while in asynchronous communication, they operate independently of each other.
- Synchronous communication involves a single sender and multiple receivers, whereas asynchronous communication involves multiple senders and a single receiver.
- Synchronous communication requires a higher bandwidth compared to asynchronous communication.
Synchronous communication requires the sender and receiver to be active simultaneously, with the sender waiting for a response before proceeding, whereas asynchronous communication allows the sender to continue operation without waiting for an immediate response. Asynchronous communication offers benefits such as decoupling of components, better scalability, and fault tolerance, albeit with potential complexities in handling out-of-order messages and ensuring eventual consistency.
Which component of the Hadoop ecosystem provides real-time, random read/write access to data stored in HDFS?
- HBase
- Hive
- Pig
- Spark
HBase is the component of the Hadoop ecosystem that provides real-time, random read/write access to data stored in HDFS (Hadoop Distributed File System). It is a NoSQL database that runs on top of HDFS.
Which of the following is a key factor in achieving high performance in a distributed system?
- Enhancing server operating systems
- Increasing server memory
- Minimizing network latency
- Reducing disk space usage
Minimizing network latency is a key factor in achieving high performance in a distributed system. Network latency refers to the delay or time it takes for data to travel between nodes in a network. By reducing network latency, distributed systems can improve responsiveness and overall performance, especially in scenarios where data needs to be exchanged frequently between distributed components. Techniques such as data caching, load balancing, and optimizing network protocols contribute to reducing network latency.
What is the core abstraction for data processing in Apache Flink?
- DataFrame
- DataSet
- DataStream
- RDD (Resilient Distributed Dataset)
The core abstraction for data processing in Apache Flink is the DataStream, which represents a stream of data elements and supports operations for transformations and aggregations over continuous data streams.
What are some advantages of using Apache Airflow over traditional scheduling tools for data workflows?
- Batch processing, manual task execution, static dependency definition, limited plugin ecosystem
- Dynamic workflow scheduling, built-in monitoring and logging, scalability, dependency management
- Real-time data processing, event-driven architecture, low-latency execution, minimal configuration
- Static workflow scheduling, limited monitoring capabilities, lack of scalability, manual dependency management
Apache Airflow offers several advantages over traditional scheduling tools for data workflows. It provides dynamic workflow scheduling, allowing for the definition and execution of complex workflows with dependencies. Built-in monitoring and logging capabilities facilitate better visibility and debugging of workflows. Airflow is highly scalable, capable of handling large-scale data processing tasks efficiently. Its dependency management features ensure that tasks are executed in the correct order, improving workflow reliability and efficiency.
What does completeness measure in data quality metrics?
- The accuracy of data compared to a trusted reference source
- The consistency of data across different sources
- The extent to which all required data elements are present
- The timeliness of data updates
Completeness is a data quality metric that measures the extent to which all required data elements are present within a dataset. It evaluates whether all necessary information is available and accounted for, without any missing or omitted values. Complete data sets are essential for making informed decisions and conducting accurate analyses.
The choice between data modeling tools such as ERWin and Visio depends on factors like ________.
- Availability of training resources and online tutorials
- Color scheme and user interface
- Cost, complexity, and specific requirements
- Operating system compatibility and file format support
The choice between data modeling tools such as ERWin and Visio depends on factors like cost, complexity, specific requirements of the project, and the availability of features required for the task.
The process of defining policies, procedures, and standards for data management is part of ________ in a data governance framework.
- Data Compliance
- Data Governance
- Data Quality
- Data Stewardship
In a data governance framework, the process of defining policies, procedures, and standards for data management falls under the domain of Data Governance. Data governance encompasses the establishment of overarching principles and guidelines for managing data effectively across the organization. It involves defining rules and best practices to ensure data is managed, accessed, and used appropriately to support organizational objectives while maintaining compliance and mitigating risks.
________ is a data extraction technique that involves extracting data from semi-structured or unstructured sources, such as emails, documents, or social media.
- ELT (Extract, Load, Transform)
- ETL (Extract, Transform, Load)
- ETLT (Extract, Transform, Load, Transform)
- Web Scraping
Web Scraping is a data extraction technique used to extract data from semi-structured or unstructured sources like emails, documents, or social media platforms, enabling analysis and processing of the data.
What does GDPR stand for in the context of data compliance?
- General Data Protection Regulation
- General Database Processing Rule
- Global Data Privacy Regulation
- Global Digital Privacy Requirement
GDPR stands for General Data Protection Regulation, a comprehensive European Union (EU) legislation designed to protect the privacy and personal data of EU citizens and residents. It imposes strict requirements on organizations handling personal data, including consent mechanisms, data breach notification, data subject rights, and hefty fines for non-compliance, aiming to harmonize data protection laws across the EU and empower individuals with greater control over their personal information.