Database Management Systems Flashcards

Which type of database model organizes data into tables with rows and columns, linked by keys?

Answer: Relational model

The relational model organizes data into tables (relations) connected via primary and foreign keys, and is the basis for SQL-based databases.

In a relational database, a PRIMARY KEY is best described as:

Answer: A field that uniquely identifies each record in a table

A primary key uniquely identifies each row in a table and cannot contain null or duplicate values.

Which SQL command is used to retrieve data from a database table?

Answer: SELECT

The SELECT statement is the SQL command used to query and retrieve data from one or more database tables.

What does ACID stand for in the context of database transactions?

Answer: Atomicity, Consistency, Isolation, Durability

ACID stands for Atomicity, Consistency, Isolation, and Durability — the four properties that guarantee reliable database transactions.

A FOREIGN KEY in a relational database:

Answer: Links a record in one table to a record in another table

A foreign key is a field in one table that references the primary key of another table, establishing a relationship between the two tables.

Which normal form eliminates partial dependencies by ensuring every non-key attribute depends on the whole primary key?

Answer: Second Normal Form (2NF)

Second Normal Form (2NF) requires that all non-key attributes are fully functionally dependent on the entire primary key, eliminating partial dependencies.

In database terminology, what is a 'schema'?

Answer: The logical structure or blueprint defining the organization of data in a database

A schema is the logical structure that defines how a database is organized, including tables, columns, data types, and relationships.