CH 5 Info Systems

Bytes and Data Organization

• Bytes and data are grouped into:
  • Columns/fields (e.g., 'S' in Sydney)
  • Rows/records (e.g., the whole name Sydney and student number)
  • Tables/files

Chapter 5: Database Processing

Overview

• Study questions 5 & 6 will not be addressed.

Traditional File Systems

• Description:
  • One of the simplest ways to store data.
  • Stores groups of records used by a specific software application together.
  • Simplicity comes with some limitations and costs, including:
  • Inability to share data: Data is often siloed within applications.
  • Inadequate security: Limited security measures can lead to vulnerabilities.
  • Data duplication: Issues such as redundancy (e.g., messy records, time-consuming processes, poor security, and limited access to one user at a time).

Purpose of a Database

• To organize and keep track of things.
• To maintain records across multiple themes.
• General rule for data organization:
  • Single theme: Store in a spreadsheet.
  • Multiple themes: Use a database (e.g., Different classes stored in separate folders).

What is a Database?

• Definition:
  • A self-describing collection of integrated records.
• Components:
  • Hierarchy of data elements.
  • Collection of tables and relationships among the rows.
  • Includes metadata: data that describes other data, such as details related to images captured.

Relationships Among Records

• Records can relate across different tables:
  • Primary Keys:
  • Definition: Unique identifiers for rows in a table.
  • Examples: Social security number, phone number, or driver's license number.

Foreign Keys

• Definition: A primary key that exists in another table (not unique in this context).
• Relational Databases:
  • Framework using tables, keys, and foreign keys to establish relationships.

Metadata

• Definition: Data that describes other data.
• Includes information such as:
  • Data type
  • Field name
  • Field properties
• Importance:
  • Enhances the utility of databases.
  • Facilitates user interaction with databases.

Database Management System (DBMS)

• Definition: A program that creates, processes, and administers databases.
• Key Functions:
  1. Creating the Database and its Structures: Designing and forming the database layout.
  2. Processing the Database: Interacting with the data.
  3. Administrating the Database: Overseeing database operations.

Processing the Database

• Structured Query Language (SQL):
  • Most widely used query language for DBMS.
  • Recognized as an international standard.
  • Four primary operations in DBMS:
  • Read: Retrieve data from the database.
  • Insert: Add new data to the database.
  • Modify: Change existing data.
  • Delete: Remove data from the database.

Administering the Database

• Responsibilities include:
  • Setting up security systems, creating user accounts, assigning passwords, specifying permissions and limits for processing.
  • Limiting user permissions based on access needs.
  • Backing up databases and improving the performance of database applications.
  • Managing unwanted data, akin to setting up a new phone where apps need to be redownloaded and accounts signed into.

Difference between DBMS and Database

• DBMS: A software program designed to manage data effectively.
• Database: An organized collection of related records containing the actual data.

Four Elements of a Database Application

1. Forms:
   • Purpose: To view data, insert new data, update existing records, and delete records.
2. Reports:
   • Definition: Structured presentations of data, utilizing operations like sorting, grouping, and filtering.
3. Queries:
   • Function: Allow users to search based on specific data values provided.
   • Example: Finding individuals based on traits like major, favorite color, or birthday (e.g., identifying people with a birthday in July).
4. Application Programs:
   • Provide security, data consistency, and specialized processing, such as managing out-of-stock situations.