TOPCIT - Data

Data

A fundamental resource that represents raw facts, figures, or observations collected from the real world in its unprocessed form. Example: Temperature readings recorded by a weather station.

Information

A structured and systematised form of data that has been processed to serve a specific purpose, making it meaningful and useful. Example: A weather report summarising temperature trends over a week.

Knowledge

A refined form of information derived from analysis, interpretation, and application of rules or theories, enabling decision-making and value creation. Example: A meteorologist predicting future weather patterns based on historical climate data and scientific models.

Batch Processing System

A data processing system that collects data over a period or in bulk and processes it all at once, making it suitable for tasks that do not require immediate results. Example: Utility companies processing monthly electricity bills in batches rather than individually in real-time.

File Handling System

Characterized by the application program directly implements the file structure, application programs improve data access by embedding the data access method, and there is program-data dependence

Real-Time Processing System

A data processing system that instantly processes incoming data, ensuring rapid response and system performance for time-sensitive operations. Example: Stock trading platforms executing buy/sell orders immediately based on market fluctuations.

On-line Processing Systems

A data processing system that connects processors and databases over a network, allowing users to request and receive immediate data processing. Example: Online banking systems enabling instant fund transfers between accounts.

Distributed Processing System

A data processing system that distributes computing tasks across multiple locations, improving efficiency, scalability, and fault tolerance. Example: Cloud-based applications leveraging multiple data centers to process user requests globally.

File Handling System

A data management system that stores and accesses data in sequential files, where application programs directly implement file structures and data access methods.

Example: Early payroll systems storing employee records in flat files, requiring custom programs to retrieve and update salary details.

Program-Data Dependence

A problem of file handling systems where application programs are tightly coupled with data structures, making modifications difficult.

Data Inconsistency

A problem of file handling systems where the same data may be represented differently across multiple files, leading to discrepancies.

Data Redundancy

A problem of file handling systems where the duplicate storage of data increases storage requirements and maintenance complexity.

Database

A structured collection of related data that is integrated and stored to serve multiple applications efficiently, overcoming the limitations of traditional file handling systems.

Example: A customer relationship management (CRM) system storing and managing customer interactions across different departments in an organization.

Stored Data

A database characteristic that keeps data in a computer-readable format for efficient retrieval and management.

Integrated Data

A database characteristic that ensures data from multiple sources is combined into a unified structure, maintaining consistency.

Operational D

A database characteristic that supports an organization's daily operations, such as transactions, reporting, and decision-making.

Shared Data

A database characteristic that allows multiple users and applications to access and manipulate data concurrently.

Database System (DBS)

A computerized system designed for storing, managing, and processing data within a database, ensuring efficient data handling and accessibility.

Example: An enterprise resource planning (ERP) system that integrates financial, human resources, and inventory data into a centralized database for streamlined operations.

User

A database system component that represents individuals who interact with the database using a query language to process data.

Database

A database system component that serves as a structured collection of stored data, ensuring organization and accessibility.

Database Language

A database system component that provides the means to manipulate, query, and define the structure of the database.

Database Management System (DBMS)

A database system component that acts as software responsible for managing, processing, and securing data within the database.

Data Independence

A database concept that separates data structure from application programs, reducing redundancy and ensuring flexibility in schema modifications.

Example: A banking system where changes to the database storage format do not affect customer-facing applications.

External Schemas

A database architecture component that defines the user's view of the database, allowing multiple tailored perspectives for different users or groups.

Example:

• A student sees only their grades and personal details.

• A professor sees student records for their courses but not financial details.

Logical Schemas

A database architecture component that represents the logical structure of the entire database, integrating external schemas into a unified global view.

Example: Defines entities like students, courses, professors, and relationships such as enrollment and grading.

Internal Schemas

A database architecture component that describes the physical storage structure, detailing how data is stored and accessed on physical media.

Example: Data is stored in indexed tables on disk, optimized for retrieval and security.

Logical Data Independence

A database characteristic that enables modifications to the conceptual schema without affecting external schemas, ensuring flexibility in logical data organization.

Physical Data Independence

A database characteristic that allows changes to the internal schema without impacting the conceptual schema, ensuring adaptability in storage mechanisms.

Database Administrator (DBA)

A database management role responsible for overseeing the database system, ensuring security, efficiency, and proper operation.

Example: In a financial institution, they manage database security, optimizes queries, and ensures compliance with data regulations.

Establishing the System

A DBA role that involves setting up and configuring the database environment.

Defining Schema

A DBA role that designs the logical structure of the database, including tables, relationships, and constraints.

Establishing Policy

A DBA role that defines rules for data access, backup, and recovery procedures.

Controlling Security

A DBA role that manages user permissions, authentication, and data protection measures.

Providing Technical Support

A DBA role that assists users and developers with database-related issues.

Managing Data Dictionary

A DBA role that maintains metadata, ensuring consistency and documentation of database structures.

Tuning Performance

A DBA role that optimizes queries, indexing, and storage to enhance efficiency.

Data User

A database role responsible for accessing and utilizing data for specific needs, including querying, updating, and reporting.

Example: A sales analyst retrieves customer purchase history using SQL queries to generate reports on buying trends.

Collecting Requirements

A data user role that involves defining data needs for business or analytical purposes.

Data Definition Language (DDL)

A database language that defines and manages database schemas, specifying how data is structured and stored.

Example: A database administrator creating a new table for customer records using the CREATE statement.

Data Manipulation Language (DML)

A database language that manipulates data within tables, allowing retrieval, insertion, modification, and deletion of records.

Example: A sales analyst updating product prices using the UPDATE statement.

Data Control Language (DCL)

A database language that manages user permissions and access control within the database system.

Example: A database administrator granting read-only access to a junior analyst using the GRANT statement.

Transaction Control Language (TCL)

A database language that manages transactions, ensuring data integrity and consistency.

Example: A banking system committing a transaction after successfully transferring funds using the COMMIT statement.

Using DML for Queries and Updates

A data user role that executes SQL commands to retrieve, modify, and manipulate data.

Accessing Data through Application Programs

A data user role that interacts with databases via software applications for business operations.

Database Management System (DBMS)

A core software system that manages databases, ensuring efficient data storage, retrieval, security, and integrity while supporting multiple users and applications.

Example: MySQL, PostgreSQL, and Oracle DBMS are widely used in enterprise applications for managing structured data.

Defining the Database Structure

A DBMS function that establishes the schema, specifying tables, relationships, and constraints.

Manipulating Data

A DBMS function that enables users to insert, delete, update, and retrieve data efficiently.

Concurrency Control

A DBMS function that manages simultaneous access by multiple users, preventing conflicts and ensuring consistency.

Security

A DBMS function that protects the database from unauthorized access through authentication and access control mechanisms.

Recovery

A DBMS function that restores the database to a consistent state after failures, ensuring data durability.

Utility

A DBMS function that provides maintenance tools such as backup, indexing, and performance monitoring.

Interface

A DBMS function that offers user-friendly interfaces, including graphical tools and query languages, for database interaction.

Integrity

A DBMS function that maintains accuracy and consistency through constraints, validation rules, and referential integrity.

Hierarchical Database

A database model that organizes data in a tree-like structure, supporting 1:N relationships but limiting flexibility in queries and relationship modifications. Example: An organizational structure where employees are grouped under departments, each reporting to a higher-level manager.

Network Database

A database model that extends the hierarchical structure into a network form, supporting M:N relationships for flexible access paths but requiring complex design and management. Example: A university course registration system, where students enroll in multiple courses, and courses have multiple instructors.

Relational Database

A database model based on set theory, storing data in two-dimensional tables with structured relationships, supporting SQL queries and data independence. Example: E-commerce platforms like Amazon use these databases to manage customers, orders, and inventory efficiently

Object-Oriented Database (OOD)

A database model that integrates object-oriented principles, supporting user-defined data types, inheritance, and complex relationships for advanced data processing. Example: 3D modeling software storing objects with attributes like shape, texture, and behavior.

Object-Relational Database

A hybrid database model combining relational and object-oriented features, supporting user-defined types, row functions, and triggers for modern applications. Example: Multimedia databases managing images, videos, and metadata with relational indexing and object-oriented attributes.

Main Memory Database

A database type that stores data in main memory instead of disk, enabling fast transaction processing and real-time decision-making. Example: Stock trading systems requiring instant data retrieval for high-frequency trading.

Embedded Database

A database type installed within an embedded system, offering portability and fast processing but limited by memory constraints. Example: Smart home devices storing sensor data for automation and control.

Mobile Database

A database type designed for mobile devices, operating independently while supporting synchronization with server databases. Example: Offline banking apps allowing transactions without an internet connection, later syncing with the central database.

Spatial Database

A database type optimized for geographical data, storing coordinate values for location-based queries and GIS applications. Example: Google Maps using spatial databases to manage roads, landmarks, and navigation routes.

XML (Extensible Markup Language)

A markup language primarily used for creating and formatting web documents, based on SGML (Standard Generalized Markup Language).

Example: XML is used in RSS feeds to structure news updates for websites.

Extensible Markup

An XML characteristic that allows users to define custom tags for structuring data.

HTML Integration

An XML characteristic that enables XML to work alongside HTML for web applications.

Self-Descriptive

An XML characteristic that allows data to be stored with metadata, making it easy to interpret.

XML Processor

A system that handles XML documents, ensuring their correctness and enabling data retrieval.

XML Editor

An XML processor component that creates and edits XML documents.

XML Parser

An XML processor component that validates XML syntax and structure.

XML Engine

An XML processor component that executes queries and transmits XML data.

DTD (Document Type Definition)

A schema definition method that verifies the structure and contents of an XML document by defining element types, attribute lists, and notation declarations.

Example: A book catalog using this to enforce consistent formatting.

<!DOCTYPE catalog [
<!ELEMENT book (title, author, price)>
<!ELEMENT title (#PCDATA)>
<!ELEMENT author (#PCDATA)>
<!ELEMENT price (#PCDATA)>
]>

#PCDATA

A data definition that originated in Standard Generalized Markup Language (SGML), and is used also in Extensible Markup Language (XML) Document Type Definition (DTD) to designate mixed content XML elements.

XML Schema

A more advanced alternative to DTD that defines the structure and constraints of XML documents, supporting data types, namespaces, and multiple document processing.

Example: A product inventory system using this for validation.

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:element name="product">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="name" type="xsd:string"/>
        <xsd:element name="price" type="xsd:decimal"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>

XQuery

A query language designed to search and retrieve XML-based data, similar to SQL for databases.

Example: Extracting book titles from an XML document.

for $book in doc("books.xml")/catalog/book
return $book/title

XLink

A linking mechanism in XML that provides advanced hyperlink functionalities, supporting simple links, extended links, and linkbases.

Example: Linking external resources in an XML document.

<article xlink:type="simple" xlink:href="https://example.com" xmlns:xlink="http://www.w3.org/1999/xlink">
    Click here for more information.
</article>

Requirements Collection and Analysis

A database design phase that involves gathering and analyzing user needs to define the database system's purpose, data requirements, and processing needs.

Example: A hospital database system requires patient records, appointment scheduling, and billing information.

Conceptual Design

A database design phase that represents the real-world information structure using Entity-Relationship (ER) modeling at a high level of abstraction.

Example: An ER diagram for a university database defining entities (Students, Courses, Professors) and relationships (Enrollment, Teaching).

Logical Design

A database design phase that converts the conceptual model into a relational structure, defining tables, primary keys, foreign keys, attributes, and integrity constraints.

Example: A normalized relational schema for an e-commerce database with tables like Customers, Orders, and Products.

Physical Design

A database design phase that defines the physical storage structure, considering file organization, indexing methods, and performance optimization.

Example: Using indexing in a banking database to speed up transaction searches.

Database Building

A database implementation phase that involves creating the actual database system using a DBMS, including SQL schema creation, data population, and query execution.

Example: Creating tables and inserting data in MySQL for an inventory management system.

Operation and Maintenance

A database management phase that ensures the database system runs smoothly through monitoring, optimization, and security measures.

Conceptual Phase

A database design consideration that defines entities, relationships, and constraints to avoid redundancy.

Logical Phase

A database design consideration that selects attributes, keys, and normalization techniques for consistency.

Physical Phase

A database design consideration that optimizes storage, indexing, and query performance for efficiency.

Roles

A database design consideration that defines responsibilities for data architects, DBAs, and developers.

Data Management System

A database design consideration that selects the appropriate DBMS based on scalability and security needs.

Data Modeling

A database design consideration that uses ER diagrams and normalization to structure data effectively.

Chen Model

An ER notation that uses rectangles for entities, diamonds for relationships, and ellipses for attributes, distinguishing between simple, composite, single-valued, multi-valued, and derived attributes.

Generalization/Specialization

A data modeling concept that represents is-a relationships, where generalization merges multiple entities into a higher-level type, and specialization decomposes an entity into subtypes.

Aggregation

A data modeling concept that represents part-of relationships, treating multiple entities as a single unit.

Degree

A relationship characteristic that defines the number of entity types participating (e.g., binary, ternary).

Connectivity

A relationship characteristic that specifies cardinality (e.g., 1:1, 1:N, N:M)

Participation Constraint

A relationship characteristic that determines whether an entity's participation is total (mandatory) or partial (optional)

Identifier

A database attribute that uniquely distinguishes each entity instance, ensuring data integrity and consistency.

Uniqueness

A database identifier characteristic that ensures each entity instance is uniquely identifiable.

Minimality

A database identifier characteristic that requires the fewest attributes necessary for uniqueness.

Immutability

A database identifier characteristic that prevents frequent changes to identifier values.

Relevance

A database identifier characteristic that ensures identifiers are meaningful within the business context.

Connection Trap

A database modeling issue that distorts information retrieval due to incorrect relationship structures.

Fan Trap

A connection trap that occurs when a 1:N:1 relationship creates an ambiguous path, preventing specific connections.