Database fundamentals V

Front

What are the key considerations during the creation step of a database?

Back

what information the databases will store, its hosting, and how it will be accessing by clients

Answer explanation

During the creation of a database, it's critical to define what data it will store, where it will be hosted (either on-premise or in the cloud), and how clients (users or applications) will access it. The visual appearance or color scheme is typically not a concern when creating a database. While the database's performance is an important factor, it is not the primary consideration during the creation phase. While managing a database lifecycle may include its deletion, the creation phase primarily focuses on defining its content, location, and accessibility.

Front

Emily is a software developer who is developing a shopping website where users can login, add items to their carts, and check out. She wants the items in the cart to remain even if the user logs out or closes the browser, meaning she wants the cart data to persist. Which technique should Emily use to ensure the data persistence?

Back

store cart data in a database

Answer explanation

Storing data in a database will ensure that the cart data remains intact, even when a user logs out or closes their browser. When the user returns and logs in again, the application can retrieve the user's cart data from the database. Session variables only maintain data while the session is active. If the user logs out or closes the browser, the information stored in the session would be lost. Volatile memory loses its stored information once power is lost, like when the system is shut down or restarted. Therefore, it is not an ideal storage medium for persisting data. Storing data in HTML code would not persist and would be lost once the user closes the session or refreshes the page. Its purpose is not for data persistence.

Front

Which operation would BEST ensure a fallback point in case of data loss, corruption, or other types of database failures? Options: Taking database backup, assigning roles and permissions to users, Writing SQL commands to interact with a database, using query builders and report generation tools

Back

Taking database backup

Answer explanation

Taking database backups refers to the process of making copies of the entire database or its parts at regular intervals. This is crucial for being able to restore data in case of corruption, loss, or failures. Assigning roles and permissions to users is a part of managing database security but isn't directly concerned with safeguarding data against loss or failures. Query builders and report generation tools are used for interacting with a database and extracting meaningful insights from data, but they don't help protect against data loss or failures. Writing SQL commands is a method of database interaction and manipulation, but it doesn't inherently safeguard data against potential loss or corruption.

Front

Which command in SQL is primarily used to modify the structure of an existing database, table, or column?

Back

Alter

Answer explanation

Explanation

The ALTER command in SQL is used to modify the structure of an existing database, table, or column, such as adding or deleting columns in a table or changing the data type of a column. "PERMISSIONS" isn't a recognized SQL command. It is a concept related to managing user rights and access within a database system, not altering object structures in a database. The DROP command in SQL eliminates existing databases, tables, or indexes. It does not modify their structure. The CREATE command in SQL is used to establish new databases, tables, or indexes. It does not modify the structure of existing ones.

Front

How does a schema impact the way a database works and how it is organized?

Back

It defines the structure of the database, including tables, fields, relationships, and constraints.

Answer explanation

A schema influences a database by defining its structure. It stipulates the organization of tables, specifies fields, establishes relationships, and sets constraints. It essentially acts as the blueprint for the database. While data security and user authorization are vital components of a database management system, they are typically separate from the schema. A schema doesn’t directly influence the graphical interface of a DBMS. Instead, it primarily impacts the database's structure and how data is organized, stored, and related. A schema does not manipulate data.

Front

Which type of database commands are used to define and manage the structure of a database, such as creating tables or altering their structure?

Back

Data Definition language (DDL)

Answer explanation

Data Definition Language (DDL) commands. DDL commands are used to define and manage the structure of a database, including creating tables, altering table structures, and defining constraints. They are responsible for managing the schema of a database. Data Query Language (DQL) is not a widely used term in database systems. While queries are an essential part of data manipulation, the term DQL is not commonly used to represent a specific category of commands related to defining or managing the structure of a database. Data Control Language (DCL) commands are used to manage user permissions and access control within a database. They do not directly deal with defining or managing the structure of a database. Data Manipulation Language (DML) commands are used to manipulate data within a database, such as inserting or updating records. They do not directly involve defining or managing the structure of a database.

Front

Which SQL command is MOST suitable for retrieving data from an SQL database? Options: DELETE, SELECT, UPDATE, INSERT

Back

SELECT

Answer explanation

Explanation

The SELECT command is used to retrieve data from a database, making it the most suitable for this operation. The UPDATE command is used to modify existing records in a database, not for retrieving data. The DELETE command is aimed at removing records from a database, not retrieving the data. The INSERT command is used to add new records into a database, not for retrieving existing ones.