Data, Information, and Database Systems Overview

Data and Information

• Data is comprised of raw, unprocessed facts and are the building blocks for information.
• Information is the result of processing raw data to reveal its meaning, requiring context.
• Information should be accurate, relevant, and timely and serves as a bedrock of knowledge.

Databases and Their Characteristics

• Databases are shared, integrated computer structures that store data.
• End-user data includes raw facts of interest to the end user.
• Metadata is data about data that integrates and manages the end-user data and describes characteristics and relationships.
• Data in today's world is ubiquitous and pervasive.
• Databases enable data persistence and facilitate secure sharing and offer specialized structures for fast data storage, management, and retrieval.
• Database Management System (DBMS) is a collection of programs that manages the database structure and controls data access.

Role and Advantages of DBMS

• The DBMS acts as an intermediary between the user and the database.
• It enables data sharing, integrates the view of data for the end user, and provides efficient data management.
• DBMS improves several processes including; sharing, security, integration and access.

Types of Databases

• Single-user databases support one user at a time, like desktop databases on a personal computer.
• Multiuser databases support multiple users simultaneously and this includes; workgroup databases for specific departments and entreprise databases supporting many users.
• Centralized databases have data at a single site.
• Distributed databases have data distributed across different sites.
• Cloud databases are created and maintained using cloud data services, providing defined performance measures.
• General-purpose databases contain a wide variety of data used in multiple disciplines.
• Discipline-specific databases contain data focused on specific subject areas.
• Operational databases are designed to support a company's day-to-day operations.
• Analytical databases store historical data and business metrics for tactical or strategic decision making.
• Data warehouses store data in a format optimized for decision support.
• Online analytical processing (OLAP) involves tools for retrieving, processing, and modeling data from data warehouses.
• Business intelligence captures and processes business data to generate decision-making information.
• Unstructured data exists in its original, raw state.
• Structured data results from formatting, where the structure is applied based on the type of processing required.
• Semistructured data is processed to some extent.
• Extensible Markup Language (XML) represents data elements in textual format.

Importance of Database Design

• Focuses on designing a database structure to store and manage end-user data.
• Leads to well-designed databases, facilitating data management and generating accurate and valuable information.
• Poorly designed databases can cause errors leading to poor decision making.

Evolution of File System Data Processing

• Manual file systems utilized physical file folders and filing cabinets.
• Computerized file systems involved a Data Processing (DP) specialist creating systems to track data and produce reports.
• File system redux includes modern end-user productivity tools like Microsoft Excel.

Basic File Terminology

• Data consists of raw facts which has little meaning if unorganized,
• Field is a character or group of characters with a specific meaning used to define and store data.
• A record is a logically connected set of one or more fields that describes a person, place, or thing.
• A file is a collection of related records.

Problems with File System Data Processing

• File systems have lengthy development times and difficultly getting quick answers.
• They have complex system administration and lack security and limited data sharing.
• Also require extensive programming.

Structural and Data Dependence

• Structural dependence means access to a file is dependent on its own structure and all file system programs are modified to conform to a new file structure.
• Structural independence indicates the file structure can be changed without affecting the application's ability to access the data.
• Data dependence means data access changes when data storage characteristics change.
• Data independence means data storage characteristics can be changed without affecting the program's ability to access the data.
• Practical significance of data dependence is the difference between logical and physical format.

Data Redundancy

• This inolves storing the same data unnecessarily in different places.
• Data Redundancy leads to islands of information (scattered data locations) and increases the chance of having different versions of the same data.
• Uncontrolled data redundancy can result in poor data security, data inconsistency, data-entry errors, and data integrity problems.

Data Anomalies

• Data anomalies develop when not all of the required changes in the redundant data are made successfully.
• Three types of data anomalies exist; update, insertion and deletion.

Database Systems

• This involves a logically related data is stored in a single logical data repository and is physically distributed among multiple storage facilities.
• Database management systems eliminate most of file system's data inconsistency, data anomaly, data dependence, and structural dependence problems.
• Current generation of DBMS software stores data structures, relationships between structures, and access paths, defining, storing, and managing all access paths and components.

The Database System Environment

• It is the organization of components that define and regulate the collection, storage, management, and use of data within a data base environment.
• The components of a Database System inclyde; hardware, software, people, procedures, and data.

DBMS Functions

• Data dictionary management stores definitions of data elements and their relationships.
• Data storage management maintains performance tuning ensures efficient performance.
• Data transformation and presentation ensures that Data is formatted to conform to expectations.
• Security management enforces user security and data privacy.
• Multiuser access is controlled by sophisticated algorithms.
• Sophisticated algorithms make suer that multiple users can access the database concurrently without compromising its integrity.
• Enables database recovery after a failure (Backup and recovery)
• Minimizes redundancy and maximizes consistency through data integrity.
• Accepts user requests (Database communication)

Structured Query Language (SQL)

• It is the de facto query language and data access standard.
• It is supported by the majority of DBMS vendors.

Disadvantages of Database Systems

• Database Systems has some disadvantages, that include; increased costs, management complexity, maintaining currency and vendor dependence.
• Frequent upgrade/replacement cycles is also a major downside to Database Systems.

Explore the fundamental concepts of data and information, highlighting their differences and importance. Understand databases as structured systems for storing and managing data. Learn about the role and advantages of Database Management Systems (DBMS) in controlling data access and ensuring data persistence.