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

Software: Definition and Functions

Software is the intangible component of any computer system. It consists of a collection of rules and guidelines that establish the relationship between the user and the machine.

Functions of Software

1. To reduce manual entry of information.
2. Provide communication media between man and machine.
3. Encourage greater use of media and reduce the processing time of files.
4. Provide routines that automatically perform repetitive, classified work.

Software Classification

System Software

A series of programs that facilitate man-machine communication, permitting its proper exploitation.

Application Software

Programs developed to solve specific problems. These can be classified into:

Basic or Utility Programs

These are applications whose... Continue reading "Software Fundamentals: Classification and Acquisition Methods" »

Test Strategy

• Test Planning
• Design test cases
• Test Run
• Collection and evaluation

The software is tested to discover errors made inadvertently when carrying out their design and construction.

The tests are a set of activities you can plan ahead and carry out systematically. For this reason, you must define the process of software engineering template for software testing.

A software testing strategy should include: evidence of low-level, high level evidence.

Verification: a set of activities to ensure that software correctly implements a specific function.

Validation: different set of activities to ensure that software built is consistent with customer requirements.

Only once the software architecture comes into play is completed Independent Test Group.

Starting a Session and Destroying Variables (inicio.php)

session_start();
unset($_SESSION["host"]);

Creating a Session and Attempting a Connection (marco.php)

session_start();
$conn = @mysql_connect($host, $user, $password) or die("Incorrect user or password");
@mysql_select_db($db, $conn) or die("Cannot open the DB");

Assigning Connection Parameters to Session Variables

$_SESSION["host"] = $host;
$_SESSION['User'] = $user;

Starting a Session, Connecting to the Database, and Sending an Insertion Query (altas.php)

<?
 session_start();
 $conn = mysql_connect($host, $user, $password) or die("Incorrect user or password");
 mysql_select_db($db, $conn) or die("Not selected");
 $query = "insert into departments values ($dep, '$nom', '$crazy')";
 $result

Database Fundamentals

A database is a set of tools designed to manage information related to a specific topic, such as books or CDs.

Core Database Components

• Tables

  Tables store data in an organized manner, featuring fields that allow information to be handled effectively.

• Queries

  Queries are tools that provide answers to questions that may arise about the stored data.

• Forms

  Forms are data objects that present information differently from a table, offering a more pleasant, colorful, and effective user interface.

• Reports

  Reports allow you to print stored data in formats designed by the user.

Understanding Data Types

Data types define the kind of values a field can hold. Here are common data types:

• Text (VARCHAR)

  Can be formed by letters, numbers, and spaces,

Network Fundamentals

The Internet: History and Evolution

The Internet was born in the U.S. in the early 1970s from a network created by the U.S. Army called ARPANET. (Sources: http://www.isoc.org/internet/history/; http://wiki.startup2.eu/index.php/Main_Page).

The Internet is not controlled or maintained by any single entity, which provides both its main advantages and disadvantages. Every person connecting is free to set the tone or ideology that will be used. While we previously focused on the Internet generally, the current discussion centers on Web 2.0 and the Social Web, driven by the continuous emergence of new services.

Web 1.0 vs. Web 2.0

The characteristics of Web 1.0 involved a server sending information to clients, determining which clients... Continue reading "Fundamental Concepts of Internet and Web 2.0 Technologies" »

Disk Quota Management in Windows Server 2008

Windows Server 2008 offers two distinct types of disk quotas to help manage storage utilization:

• NTFS Disk Quotas

  Available in all versions of Windows Server 2008, NTFS Disk Quotas allow administrators to manage the disk space used by users. Quotas are set for each volume. While users receive warning messages when exceeding their quota, event logging is the primary communication channel for disk quota management.

• File Server Resource Manager (FSRM)

  Windows Server 2008 supports File Server Resource Manager (FSRM) for advanced quota management. FSRM enables the management of space utilization for specific folders and volumes. Users approaching or exceeding their limits will automatically receive email notifications.

Features of Free Software

Free software provides the following freedoms:

• The freedom to run the program for any purpose.
• The freedom to study how the program works and adapt it to your needs.
• The freedom to redistribute copies so you can help others.
• The freedom to improve the program and release improvements to the public, so that the whole community benefits.

Sharing Resources in Windows

To share network resources in Windows, you need to ensure that file and printer sharing is enabled in the local area network configuration. To do this, go to "Network Connections", right-click on "Local Area Connection", and select "Properties".

Types of Users

• Administrator or Root: Responsible for configuration and maintenance.
• User: Uses the system and accesses resources

Processor Front

The processor front involves three components: source, destination, and message. The source (e.g., a terminal or computer) sends a message. The destination (e.g., another terminal or computer) receives the message. The front-end processor acts as the connection between the source and destination, managing the message transfer. It frees the host processor from communication tasks, handling message routing, transmission monitoring, code translation, and encryption. All data transmitted to or from the host processor are managed through this specialized front-end processor, allowing the host processor to operate more efficiently and focus on application processing.

Types of Communications

A network enables computer connections to share... Continue reading "Computer Network Communications" »

Software Development Models

Attributes of Effective Requirements (AtrERS): Correct, unambiguous, complete, verifiable, consistent, modifiable, concise, organized, searchable, understandable by the client, regardless of design.

Scaling Factors: Correctness, reliability, efficiency, integrity, ease of use and maintenance, flexibility, ease of testing, portability, reusability, ease of interoperation.

Life History: Succession of stages through which a software product passes during its existence. Attempts to determine the order of the steps involved and the criteria associated with the transition between these stages.

Software Engineering: Application of scientific knowledge to the design and construction of computer programs and associated documentation... Continue reading "Software Development Models: Waterfall, Prototype, and More" »

Advanced Features

Advanced features facilitate consultation similar to a spreadsheet because they work based on rows and columns.

• COUNT(): Count the number of rows in the column set
• MIN(): Find the minimum value of the column set
• MAX(): Find the maximum value of the column set
• AVG(): Gets the average values in the column set
• SUM(): Gets the total value implied by the values obtained in the column provided

Modifying the Database

SQL DDL has modules for the definition of data that allows us to create or modify table structure.

The instructions for these operations are:

• CREATE TABLE: Allows you to create an empty data table.
• INSERT: Allows you to store records in a table created.
• UPDATE: You can modify data records stored in the table.
• DELETE: Deletes a record