How does data warehousing differ from traditional relational database systems?
- Data warehousing does not support complex queries
- Data warehousing focuses on historical and analytical queries
- Data warehousing is not suitable for large datasets
- Data warehousing uses NoSQL databases
Data warehousing differs from traditional relational database systems by primarily focusing on historical and analytical queries rather than transactional processing. It involves storing and managing large volumes of data for reporting and analysis.
The ________ component of an ETL tool is responsible for loading transformed data into the target system.
- Extraction
- Integration
- Loading
- Transformation
The loading component of an ETL tool is responsible for loading transformed data into the target system, such as a data warehouse or a database. It completes the ETL process by making data available for analysis.
Data modeling best practices advocate for the use of ________ to facilitate collaboration and communication among team members.
- Data dictionaries
- Data lakes
- Data warehouses
- Entity-Relationship diagrams (ER diagrams)
Entity-Relationship diagrams (ER diagrams) are commonly used in data modeling to visually represent data structures, relationships, and attributes, aiding collaboration and understanding.
Data cleansing is a critical step in ensuring the ________ of data.
- Accuracy
- Completeness
- Consistency
- Integrity
Data cleansing, also known as data cleaning or data scrubbing, focuses on ensuring the completeness of data by removing or correcting errors, inconsistencies, and inaccuracies. It involves processes such as removing duplicate records, correcting typos, and standardizing formats to improve data quality and reliability for analysis and decision-making.
Scenario: Your distributed system relies on message passing between nodes. What challenges might arise in ensuring message delivery and how would you address them?
- Message duplication and out-of-order delivery
- Network latency and packet loss
- Node failure and message reliability
- Scalability and message throughput
In a distributed system relying on message passing, challenges such as network latency, packet loss, and node failures can impact message delivery and reliability. To address these challenges, techniques like message acknowledgment, retry mechanisms, and message queuing systems can be implemented. Using reliable messaging protocols such as TCP/IP or implementing message brokers like RabbitMQ can ensure guaranteed message delivery even in the presence of network failures or node crashes. Additionally, designing fault-tolerant architectures with redundancy and failover mechanisms can enhance the reliability of message delivery in distributed systems.
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.
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.
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.
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.
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.