CompTIA Tech+ (FC0-U71) Practice Questions: Data and Database Fundamentals Domain

Correct Answer: A

Explanation: CRUD stands for Create, Read, Update, and Delete, which are the four basic operations for managing data in a database. Options B, C, and D do not correctly represent these operations.

Correct Answer: B

Explanation: A differential backup captures all data changes since the last full backup. An incremental backup captures only the changes made since the last backup of any type, a full backup captures all data, and a snapshot backup is a point-in-time copy of the data.

Correct Answer: C

Explanation: A relational database organizes data into tables, which can be linked—or related—based on data common to each. Option A is incorrect because a hierarchical database organizes data in a tree structure. Option B is incorrect because a network database uses a graph structure. Option D is incorrect because a flat file database stores data in a single table.

Correct Answer: B

Explanation: The main purpose of a database backup is to ensure data can be recovered in case of data loss due to hardware failure, software issues, or other disasters. Option A is incorrect as backups do not increase performance. Option C is related to database concurrency, and option D pertains to data analysis, not backups.

Correct Answer: C

Explanation: The main advantage of NoSQL databases is their ability to handle unstructured data more efficiently than traditional relational databases. Option A is not always true, Option B is unrelated to NoSQL's primary benefits, and Option D is incorrect as all databases require backups.

Correct Answer: C

Explanation: The SELECT command in SQL is used to retrieve data from a database. INSERT is used to add new data, DELETE is used to remove data, and UPDATE is used to modify existing data.

Correct Answer: D

Explanation: The SELECT operation is used to retrieve data from a database based on specific criteria. Option A (INSERT) is used to add new data. Option B (UPDATE) is used to modify existing data. Option C (DELETE) is used to remove data.

Correct Answer: B

Explanation: A foreign key is used to establish a relationship between two tables by referencing the primary key of another table. Option A is incorrect because a foreign key does not uniquely identify records. Option C is incorrect as foreign keys are not used for storing binary data. Option D is incorrect as foreign keys do not encrypt data.

Correct Answer: C

Explanation: MongoDB is an example of a NoSQL database, which is designed to handle unstructured data and scale horizontally. MySQL (A), PostgreSQL (B), and Oracle (D) are examples of relational databases.

Correct Answer: A

Explanation: A primary key is a field that uniquely identifies each record in a table, ensuring that no two records have the same value in this field. Option B is incorrect because a primary key is not specifically for storing large text data. Option C is incorrect because primary keys do not store calculated values. Option D is incorrect because primary keys do not allow duplicate values.