Databases

Records

Structured data refers to any data that resides in a fixed field within a record or file so that it can be easily entered, stored, queried, and analysed.

Records

Records are made up of fields.
For example, a person could be represented as a record where the fields include their name, age, and address.

Comma separated values (CSV)

One method of storing a record is using comma separated values.
Each record is put on its own line.
Each field is separated by a special character such as a comma.

Pros and cons

Pros:
- Very simple, text-based format.
- Can be read by many applications.
- Easy to use in programs.
Cons:
- Inefficient for large datasets.
- Can only store text data.
- No built-in means of sorting or searching.

Flat-File Databases

Flat-file databases are used to store records of information in order to be searched or queried at a later date.

Structure of flat-file databases

A flat-file database is one that has a single table to store data about an 'entity'.
The table stores data in fields (columns) such as date of birth.
A record (row) of information is a complete set of fields put together.
- This could be a person's details such as name, address, date of birth, telephone number.

Redundancy

Redundant data is data that is repeated in a database.
A single table file is inefficient as it is full of redundant data

Primary key

A primary key is a field used to uniquely identify a specific row of data in a table.
For example, each student in a college database will have a student ID number that is unique to each student that can be used as a primary key

Relational Database

A relational database is a set of tables whose records are linked by certain fields.

Relational database

A relational database is a set of tables whose records are linked by certain fields.
Each table contains data on one entity e.g. students or parents.
When you link one table to another, this is known as a relationship.
Each table then has a relationship to other tables using primary and foreign keys.

Foreign key

If the primary key of one table is placed into another table, this is then known as a foreign key.
For example, when a student ID field is added to a parent table to link you to your parents accounts, that student ID is a primary key in the student table but becomes a foreign key in the family table.
The parents table will have its own primary key.

Secondary key

A secondary key may also be kept by the database.
A parent may not know their child’s student ID, but they will be able to locate their last name in the database.
Secondary keys do not need to be unique.

1Components of a Computer

1.1Structure & Function of the Processor

1.1.1Structure of the CPU

1.1.2Fetch, Decode, Execute Cycle

1.1.3Factors Affecting CPU Performance

1.1.4CPU Architecture

1.2Types of Processors

1.2.1CISC & RISC

1.2.2Multicore & Parallel Cores

1.3Input, Output & Storage

1.3.1Computer Systems

1.3.2Magnetic Storage

1.3.3Optical Storage

1.3.4Types of Optical Storage

1.3.5Types of Memory

1.3.6Flash Memory

1.3.7Virtual Memory

2Software & Software Development

3Exchanging Data

4Data Types, Data Structures & Algorithms

4.1Data Types

4.1.1Data Types

4.1.2Arrays & Strings

4.1.3Representing Numbers

4.1.4Binary Arithmetic

4.1.5Hexadecimal

4.1.6Converting Binary Numbers

4.1.7Floating Points in Binary

4.1.8Floating Point Arithmetic

4.1.9Bitwise Manipulation

4.1.10Character Sets

4.2Data Structures

4.2.1Arrays, Linked Lists & Queues

4.2.2Graphs, Hash Tables & Stacks

4.2.3Trees

4.3Boolean Algebra

4.3.1Computational Logic

4.3.2Boolean Logic

4.3.3Karnaugh Maps

4.3.4Boolean Identities

4.3.5Flip Flops & Adder Circuits

5Legal, Moral, Cultural & Ethical Issues

5.1Computing Related Legislation

5.1.1Data Protection Act (1998)

5.1.2Computer Misuse Act (1990)

5.1.3Copyright Designs and Patents Act (1988)

5.1.4Regulation of Investigatory Powers Act (2000)

5.2Moral & Ethical Issues

5.2.1Online Activity Tracking

5.2.2Censorship

5.2.3Cultural Issues

5.2.4Environmental Issues

5.2.5Layout, Colour Paradigms & Character Sets

6Elements of Computational Thinking

6.1Thinking Abstractly

6.1.1Abstraction

6.2Thinking Procedurally

6.2.1Decomposition

6.3Thinking Logically

6.3.1Pseudocode & Flow Diagrams

7Problem Solving & Programming

7.1Programming Techniques

7.1.1Programming Fundamentals

7.1.2Modularity

7.2Programming Construction

7.2.1Integrated Development Environments

7.2.2Testing

8Algorithms

8.1Algorithms

8.1.1Interpreting, Correcting & Completing Algorithm

8.1.2Sort Algorithms

8.1.3Insertion & Merge Sort

8.1.4Search Algorithms

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