Enhanced models and applications: temporal, multimedia, XML, distributed databases, data warehousing, OLAP-OLTP, data mining techniques and Big Data (MapReduce, Hadoop) and NoSQL systems. - One Line Questions

1. In XML, what is a 'tag' used to define? An element or structure within the document
2. What is the primary function of Hadoop MapReduce? A programming model for processing large datasets in parallel across clusters.
3. What is a 'data mart' in a data warehousing context? A small, single-subject data warehouse tailored to the needs of a specific department or user group.
4. What is a 'distributed transaction' in the context of distributed databases? A transaction that involves updates to data stored at multiple network sites.
5. What is a 'shredded' XML document in the context of storing XML in relational databases? An XML document whose content is broken down and stored across multiple relational tables.
6. Which data mining technique is used to group similar data instances together? Clustering
7. Which data mining technique is analogous to supervised learning where the goal is to predict a numerical value? Regression
8. In Hadoop MapReduce, what does the 'Map' phase typically do? Processes input data and generates intermediate key-value pairs.
9. What does 'eventual consistency' mean in the context of some NoSQL databases? Data will eventually become consistent across all replicas, but there might be a delay.
10. Which type of NoSQL database is optimized for storing and retrieving key-value pairs? Key-Value Store
11. Which of the following is a key challenge in distributed databases? Ensuring data consistency across multiple sites.
12. What is a challenge related to distributed database concurrency control? Ensuring that transactions do not interfere with each other across multiple sites.
13. A 'fact table' is a central component in which data warehousing structure? Star Schema
14. Which of the following is a common data modeling technique used in data warehousing? Star Schema
15. What is the main characteristic of OLAP operations compared to OLTP operations? Focus on complex analytical queries involving large historical data.
16. Which of the following is a potential challenge in managing temporal databases? Handling the large volume of historical data and efficiently querying time intervals.
17. Which component of Hadoop is responsible for resource management and job scheduling? YARN
18. Which technique is commonly used to improve the performance of OLAP queries on large data cubes? Pre-aggregation of data (materialized views).
19. What is the primary benefit of using a data mining approach over traditional statistical analysis for certain problems? It can uncover complex, non-linear patterns in large datasets automatically.
20. Which type of NoSQL database stores data in JSON-like documents, allowing for flexible and nested structures? Document Database
21. Which NoSQL database type is most suitable for representing social network connections or recommendation engines? Graph Database
22. What is the main advantage of using HDFS over traditional file systems for Big Data? Designed for fault tolerance and high throughput for large files across a cluster.
23. In data warehousing, what does 'OLAP' stand for? Online Analytical Processing
24. Which of the following best describes 'OLTP'? Online Transaction Processing systems designed for high-volume, short, atomic transactions.
25. What does the 'classification' technique in data mining aim to do? Assign data points to predefined categories or classes.
26. Association rule mining, like 'Apriori', is primarily used for what purpose? Discovering relationships between items (e.g., market basket analysis).
27. In Hadoop MapReduce, what does the 'Reduce' phase typically do? Combines intermediate results from the map phase into final outputs.
28. Which type of database model is designed to handle time-varying data, allowing queries about past, present, and future states? Temporal Database Model
29. Which of the following is a common data format for XML documents? Hierarchical structure with tags
30. The 'Slice' operation in OLAP typically involves: Selecting a subset of a cube by choosing a single value for one of its dimensions.
31. Which of the following is a core concept in Big Data processing frameworks? Distributed computing
32. Which OLAP operation allows users to navigate through different levels of detail in a data hierarchy? Drill-down/Roll-up
33. What is 'Big Data' generally characterized by? High volume, high velocity, and high variety of data.
34. What is a common use case for distributed databases? Applications requiring high availability and geographic distribution of data, like global e-commerce.
35. Which standard is commonly used for representing and querying semi-structured data, particularly in web applications? XML
36. Graph databases are designed to excel at: Representing and querying complex relationships between data points (nodes and edges).
37. What is the primary characteristic of a multimedia database? Storing and managing various types of media like images, audio, and video.
38. Column-family stores (like Cassandra) are particularly well-suited for: Applications with very high write loads and large datasets distributed across many servers.
39. Which of the following is a characteristic of NoSQL databases? Schema-less or flexible schema design.
40. NoSQL is often chosen for applications requiring: High scalability, availability, and handling of unstructured or semi-structured data.
41. What are 'dimension tables' in a star schema? Tables providing context or descriptive attributes for the facts.
42. In multimedia databases, what is a key challenge related to data storage and retrieval? The large size of media files and the need for efficient indexing and searching based on content.
43. In a temporal database, what is a 'valid time' interval? The period during which a fact is true in the real world.
44. In the context of Big Data, what does 'velocity' refer to? The speed at which data is generated and needs to be processed.
45. What does the 'variety' aspect of Big Data refer to? The different types of data (structured, semi-structured, unstructured).
46. In temporal databases, what is 'transaction time'? The time a fact is recorded or modified in the database.
47. What is the purpose of the Hadoop Distributed File System (HDFS)? To store very large files across multiple machines in a cluster.
48. What is the primary goal of 'data mining' when applied to customer data? To identify customer segments, predict churn, or recommend products.
49. What is the goal of data mining? To extract hidden patterns and knowledge from large datasets.
50. What is the primary purpose of a data warehouse? To facilitate business intelligence and decision support by integrating data from various sources.