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.