BYU-ITC-515R-ACT

Homework 7 – Database Servers

1. Question: (True/False) A relational database organizes data into tables with rows and columns.
   • Answer: True
2. Question: (True/False) SQL stands for Structured Query Language.
   • Answer: True
3. Question: (True/False) All databases use SQL as their query language.
   • Answer: False
4. Question: What command is used to retrieve data from a SQL database?
   • Answer: SELECT
5. Question: What command is used to add new data to a SQL database table?
   • Answer: INSERT
6. Question: What command is used to modify existing data in a SQL database table?
   • Answer: UPDATE
7. Question: What command is used to remove data from a SQL database table?
   • Answer: DELETE
8. Question: A foreign key is used to link two __ together.
   • Answer: tables
9. Question: (True/False) A database index improves data retrieval speed.
   • Answer: True
10. Question: What command is used to grant permissions to a SQL database user?
    • Answer: GRANT
11. Question: What command is used to revoke permissions from a SQL database user?
    • Answer: REVOKE
12. Question: (True/False) PostgreSQL is an open-source relational database management system.
    • Answer: True
13. Question: (True/False) PostgreSQL uses MySQL as its default query language.
    • Answer: False
14. Question: (True/False) PostgreSQL can handle both SQL and JSON queries.
    • Answer: True
15. Question: What command is used to connect to a PostgreSQL database from the command line?
    • Answer: psql
16. Question: What flag allows you to specify the database name when connecting using psql?
    • Answer: -d
17. Question: What command lists all databases in PostgreSQL?
    • Answer: \l or \list
18. Question: What command lists all tables in the current PostgreSQL database?
    • Answer: \dt
19. Question: How do you create a new database named testdb in PostgreSQL?
    • Answer: CREATE DATABASE testdb;
20. Question: How do you delete a database named testdb in PostgreSQL?
    • Answer: DROP DATABASE testdb;
21. Question: What command creates a new user named dbuser with a password password123?
    • Answer: CREATE USER dbuser WITH PASSWORD 'password123';
22. Question: What command grants all privileges on a database named testdb to user dbuser?
    • Answer: GRANT ALL PRIVILEGES ON DATABASE testdb TO dbuser;
23. Question: What command revokes all privileges on testdb from dbuser?
    • Answer: REVOKE ALL PRIVILEGES ON DATABASE testdb FROM dbuser;
24. Question: What command starts the PostgreSQL service on a Linux system? Assume you are not the root user.
    • Answer: sudo systemctl start postgresql
25. Question: What command stops the PostgreSQL service? Assume you are not the root user.
    • Answer: sudo systemctl stop postgresql
26. Question: What command checks the status of the PostgreSQL service? Assume you are not the root user.
    • Answer: sudo systemctl status postgresql