Database Management System - Cambridge Level 9 Computer Science

This set of flashcards covers fundamental database management concepts, including flat files vs. DBMS, tables, fields, records, data types, primary keys, and the relational database management system (RDBMS).

What is the definition of a database?

An organised collection of related information that stores facts so they can be easily found, used, and updated.

List three everyday examples of databases mentioned in the transcript.

A phone contacts list, a school's student records, and a library's book catalogue.

What is a flat file?

A storage method that holds data in ONE single table or list, similar to a spreadsheet, with no links between different sets of data.

What are two disadvantages of using flat files as data grows?

Information is often duplicated (data duplication) and the data becomes hard to search, sort, or update safely.

What does the abbreviation DBMS stand for?

Database Management System.

What is the primary role of a DBMS?

It is software that allows users to create, store, organise, and manage data in a database while controlling access and maintaining accuracy.

Which software applications are provided as examples of a DBMS?

LibreOffice Base, Microsoft Access, and MySQL.

Why is a DBMS needed to handle data?

To remove duplicate data, keep data accurate and consistent, provide fast searching and filtering, and ensure security by allowing only authorized users.

In a DBMS table, how is data organised?

Data is organised into rows and columns, where each table focuses on one specific topic such as Students, Books, or Orders.

What is a field in a DBMS table?

A single COLUMN in a table that stores one specific type of detail about the subject, such as a name or a class.

What is a record in a DBMS table?

A single ROW in a table that holds all the details about ONE specific item, such as all information regarding a single student.

What is the purpose of a data type?

It tells the DBMS what KIND of value a field will hold, such as words, numbers, or dates.

Why are data types important for a DBMS?

They stop incorrect information from being entered, save storage space, allow for correct calculations, and help the system process data faster.

List the common data types mentioned in the lecture and an example for each.

Text (e.g., Ravi Kumar), Number (e.g., $42$), Date/Time (e.g., $12$-May-$2011$), Currency (e.g., $25.50$), Yes/No (True/False), and Memo (long paragraph).

What is a primary key?

A special field that gives every record a unique value so that no two rows in a table are the same.

What are the essential characteristics of a primary key?

It must be UNIQUE, it cannot be left empty (no NULL values), its value should not change over time, and every table should have exactly one.

What does RDBMS stand for?

Relational Database Management System.

What is the main difference between data storage in a DBMS versus an RDBMS?

A DBMS stores data as separate files or simple tables with little link between them, while an RDBMS stores data in related tables linked by keys to reduce duplication.

What is a foreign key?

A field in one table that matches the Primary Key of another table, used to create a link between the two tables.

Why are foreign keys necessary in an RDBMS?

They connect related tables so data isn't repeated, keep data consistent, and prevent broken or 'orphan' links between records.