CSF 7.5 Assessment - Relational Databases

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Which turtle best portrays your current mood?

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Which of the following best describes a database?

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A collection of related data organized in a structured manner.

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Which of the following statements best describes a query? A query is a type of database used to store information. A query is a request for information from a database. A query is a type of programming language used to create websites. A query is a method for storing files on a web server.

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A query is a request for information from a database.

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Which of the following are examples of tables in a relational database? Rows of data in a CSV file, Worksheets in a Microsoft Excel file, Collections of JSON documents in a NoSQL database, Customer orders and products in an e-commerce database

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Customer orders and products in an e-commerce database

Answer explanation

Customer orders and products in an e-commerce database. In a relational database, tables are used to store different types of entities or data objects, and each table has a unique name and a set of columns that represent different attributes or properties of the data. Examples of tables in a relational database might include customer data, order data, product data, and so on.

In a JSON document, data is organized into a collection of key-value pairs, where each key represents a unique identifier for a value, and the value can be of a variety of data types, including strings, numbers, boolean values, arrays, and even other JSON objects.

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Which of the following is true about relational databases? Each row has a unique identification number. Each piece of data has an associated row and column. For a column header named "age," duplicate age values are allowed. All of these options

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Each piece of data has an associated row and column.

Answer explanation

In a relational database, data is stored in tables with columns representing different attributes or fields and rows representing individual records or instances of data. Each piece of data, such as a name or age, is associated with a particular row and column in the table.

Regarding the other statements:

Each row has a unique identification number: This statement is not necessarily true. While it is common for relational databases to have a unique identifier column, such as an ID or primary key, not all databases require one.

For a column header named "age," duplicate age values are allowed: This statement is not true. Relational databases enforce integrity constraints to ensure that duplicate values are not entered into a column that has been designated as unique.

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What does the term "noSQL" refer to?

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A type of database management system

Answer explanation

"noSQL" stands for "not only SQL" and refers to a type of database management system that is non-relational and does not use SQL as its primary query language.

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Which of the following statements is true? Relational databases were used in the past but can’t be used anymore because of big data. Relational databases work better and faster with big data than NoSQL databases. Relational databases are still used today, but NoSQL databases work better and faster with big data. Relational databases and NoSQL databases both work equally well and fast on big data.

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Relational databases are still used today, but NoSQL databases work better and faster with big data.

Answer explanation

Relational databases were commonly used in the past and are still widely used today. However, with the rise of big data and the need to process and analyze large volumes of unstructured or semi-structured data, NoSQL databases have become increasingly popular. NoSQL databases are designed to handle large amounts of unstructured data and can scale horizontally, making them well-suited for big data applications. However, relational databases still have their place in certain applications where data is well-structured and requires strong data integrity and consistency.

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What is one of the disadvantages of using distributed data storage like NoSQL?

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Different users might have different views of the database at the same time.

Answer explanation

Distributed data storage systems like NoSQL often operate on a cluster of machines or servers, with data partitioned and distributed across them. While this architecture can offer many benefits such as scalability and fault-tolerance, it also introduces the risk that if one part of the system fails, it can cause the entire system to fail. This is known as the "single point of failure" problem, and it is a significant disadvantage of distributed data storage systems like NoSQL. To mitigate this risk, distributed systems often use techniques such as replication, sharding, and load balancing to ensure that data remains available and accessible even if one or more nodes in the system fail.

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When would a relational database be a better choice than a NoSQL database? Options: For a large shopping site like Amazon, For an app where thousands of users have individual data available on their phones, For a voting system in a small high school, A relational database is never a better choice than a NoSQL database

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For a voting system in a small high school

Answer explanation

Relational databases are well-suited for applications where data is well-structured and requires strong data integrity and consistency. A voting system is a good example of an application where the accuracy and consistency of data is paramount, and relational databases are designed to handle this type of data. In contrast, NoSQL databases are better suited for handling unstructured or semi-structured data, which may not fit neatly into a relational data model.

For a large shopping site like Amazon, NoSQL databases would be a better choice as they can handle large volumes of unstructured data and scale horizontally to handle high traffic and transactional loads. For an app where thousands of users have individual data available on their phones, a NoSQL database would also be a better choice, as it can handle large amounts of unstructured data and provide fast, real-time access to individual user data.

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Consider the following two statements about NoSQL databases:
I. Users can always access the database, such as performing searches, even while it is being updated by another user or when part of the database is unavailable.
II. The information available to each user is not always up to date.
Which of the following best describes the statements about the tradeoffs of NoSQL?

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I is an advantage, and II is a disadvantage

Answer explanation

The following best describes the statements about the tradeoffs of NoSQL: I is an advantage, and II is a disadvantage.

Statement I is an advantage of NoSQL databases. In a distributed NoSQL database, data is often replicated across multiple nodes, which enables users to access the database even if some parts of it are unavailable or being updated by other users.

Statement II is a disadvantage of NoSQL databases. Because NoSQL databases often use eventual consistency, it is possible that some users may not see the most up-to-date information. This is because updates to the database are not immediately propagated to all nodes in the cluster, but are instead propagated over time until eventually all nodes have the same view of the data. This can result in some users seeing stale or outdated information. However, eventual consistency is often considered an acceptable tradeoff for the benefits of scalability and availability provided by NoSQL databases.