Understanding Database Management Systems

What is a relational database?

• A relational database is a type of cloud storage service.

• A relational database is a database that organizes data into tables with defined relationships between them.

• A relational database is a collection of unstructured data.

• A relational database is a system that only stores images and videos.

Define primary key in a relational database.

• A primary key is an optional field in a database table.

• A primary key is a unique identifier for a record in a relational database table.

• A primary key is a foreign key in another table.

• A primary key can contain duplicate values.

What does SQL stand for?

• Standard Query Language

• Structured Query List

• Simple Query Language

• Structured Query Language

Write a basic SQL query to select all records from a table.

• GET * FROM table_name;

• SELECT * FROM table_name;

• FETCH * FROM table_name;

• SELECT ALL FROM table_name;

What is the purpose of database normalization?

• To enhance security by restricting data access.

• The purpose of database normalization is to minimize redundancy and dependency by organizing fields and table relationships.

• To increase data duplication for faster access.

• To simplify complex queries by merging tables.

Explain the first normal form (1NF).

• A table is in First Normal Form (1NF) if it contains nested tables within its columns.

• A table is in First Normal Form (1NF) if it has at least three columns with different data types.

• A table is in First Normal Form (1NF) if it contains only atomic values, each column has unique names, and all entries in a column are of the same type.

• A table is in First Normal Form (1NF) if it allows duplicate values in a column.

What is a foreign key?

• A foreign key is a field that links two tables by referencing the primary key of another table.

• A foreign key is a unique identifier for a table.

• A foreign key is a type of primary key.

• A foreign key is a field that stores data from the same table.

List two types of data integrity constraints.

• Data Redundancy

• Entity Integrity, Referential Integrity

• Data Encryption

• Data Normalization

What is the difference between a unique constraint and a primary key?

• A primary key can have duplicate values, while a unique constraint cannot.

• A primary key cannot be null and uniquely identifies records, while a unique constraint can allow nulls and ensures uniqueness.

• Both primary keys and unique constraints can be null.

• A unique constraint is used for foreign keys, while a primary key is not.

Name a popular database management tool.

• MongoDB

• SQLite

• MySQL

• PostgreSQL