Notes, summaries, assignments, exams, and problems for Computers

Fundamental Database Concepts

What is a datasheet?

When you first open a datasheet, Microsoft Access selects the first field value in the first record.

What is a table?

All fields for a specific individual or place can be grouped together as a table.

How can a field be described?

A field can be described as an attribute.

What is a primary key?

A field, or a combination of fields, that has a unique value is a primary key.

What is a requirement for a primary key?

A primary key must contain a unique value for each record within the table.

What is a foreign key?

A field that is defined in one table and is also a primary key in a different table is a foreign key.

What is a requirement for a foreign key?

Every foreign key must match the field value of a primary

Database Design Fundamentals

Key Concepts and Definitions

Data Type

The data type determines what field values are allowed and what other properties the field will have.

Saving a Table

You can specify a name for a table after you click the Save button on the Table Design toolbar.

Table Structure

The final step in the creation of a table is to save the table structure to disk.

Primary Key

A primary key uniquely identifies each record in a table.

Identifying Fields

When designing a database, you need to identify the fields that will be required.

Data Redundancy

Storing the same data field in multiple tables is called data redundancy.

Composite Key

A primary key that consists of more than one field is called a composite key.

Avoiding Data Redundancy

When designing... Continue reading "Database Design: Mastering Data Types, Keys, and Queries" »

Design patterns offer proven solutions to recurring software design challenges, promoting code reusability, maintainability, and efficiency. They can be categorized into three main types:

Behavioral Design Patterns

These patterns focus on communication and interaction between objects, enhancing flexibility. Examples include:

• Observer Pattern: Enables one-to-many dependencies, where changes in one object automatically notify dependent objects.
• Iterator Pattern: Provides sequential access to elements within a collection without exposing its underlying structure.

Creational Design Patterns

These patterns address object creation mechanisms, ensuring suitable instantiation processes. Examples include:

• Singleton Pattern: Restricts object creation to a single

Understanding Deadlock

A deadlock is a critical situation in which two or more computer programs, sharing the same resource, effectively prevent each other from accessing that resource. This results in both programs ceasing to function or becoming unresponsive.

Historically, the earliest computer operating systems ran only one program at a time, making all system resources available to that single program. As operating systems evolved to run multiple programs concurrently through interleaving, programs initially had to specify their resource needs in advance to avoid conflicts.

The advent of dynamic resource allocation, where programs could request further resources after execution began, introduced the problem of deadlocks. Addressing deadlocks... Continue reading "Deadlock and Semaphores: Concurrency in Operating Systems" »

Structural Design Patterns

Decorator - Adds additional functionality to a class

Adapter - 'adapts' one interface for a class into one that the client expects

Façade - creates a simplified interface from an existing one

Flyweight - A high quantity of objects share common properties to save space.

Bridge - decouples an abstraction from its implementation so that the two can vary independently.

Behavioral Design Patterns

Chain of Responsibility - Linked list of handlers

Command - Enables all the info for a request to be contained within a single object.

Interpreter - Developing domain specific languages

Iterator - Sequentially access elements of an aggregate object.

Mediator - Removes the need for classes to communicate with each other directly.

Observer... Continue reading "Structural and Behavioral Design Patterns in Software Development" »

Understanding the Internet: A Global Network

The Internet is a global network of interconnected computers that any device can join. It functions as a Wide Area Network (WAN), which is essentially a series of connected Local Area Networks (LANs).

Data packets are transmitted between computers using protocols that govern how information is sent and received.

Key Internet Technologies and Services

Technologies and services available over the Internet include:

• Web Pages: HTML documents presenting images, sound, and text, accessed via a web browser.
• Web Applications: Software accessed through a web browser.
• Native Applications: Applications developed for specific devices (e.g., smartphones), accessible without a browser.
• Email: Electronic mail communication.

Data Project Management: A Comprehensive Guide

Goal Setting: The Foundation of Project Planning

Every project requires a clear destination to determine its success. Goal setting is the first step in project planning, providing a roadmap for the project's journey.

Tools & Skills: Assessing Project Resources

The upper blocks of DR (Data Requirements) focus on evaluating the resources necessary for data project implementation. These resources include:

• Hard Resources: Data, software tools, processing
• Soft Resources: Skills, domain expertise, human resources for execution

Process & Value: Implementation and Delivery

The lower blocks of DR concentrate on project implementation and delivery. DR serves as a planning tool, helping project managers:

• Identify

Inserting Tables into Slides

In the Insert Object dialog box, click the Create From File option and click Browse to locate and choose the document or spreadsheet that contains the table. By default, the presentation software will insert the table. When you click OK, the entire document or spreadsheet is imported to your slide. Double-click the inserted text to remove extra text if the document contains more than the table. If you check the Link checkbox while inserting, after you update the table in the document or spreadsheet, then right click on the imported table in the presentation software, and select the option Update Link, the embedded table gets updated automatically. Drag and drop the table on the slide to position it.

Chart Design Principles

Convey... Continue reading "Embed and Link Objects in Presentations: Best Practices" »