Introduction to Spatial Databases Unit 6

Introduction to Spatial Databases

• Unit 6 focuses on spatial databases.
• The date of the presentation is 12/25/2020.

Fundamental Database Concepts

• Database Management System (DBMS): Provides the framework for information systems, fundamentally changing how organizations operate. It's an active area of research.
• File-Based System (Predecessor): A collection of application programs; typically produced reports. Each program manages its own data. Significant problems include data redundancy and program data dependency.
• Database Approach: Addresses file-based system problems. A shared collection of related data, described to meet organizational needs.
• DBMS (Database Management System): Software enabling users to define, create, maintain, and control access to a database.

Fundamental Database Concepts - Application Programs

• Application Program: A computer program interacting with the database, typically via SQL statements.
• The database system defines a collection of application programs that interact with the database, and the DBMS itself.

Fundamental Database Concepts - DBMS Provides

• Data Definition Language (DDL): Allows users to define the database.
• Data Manipulation Language (DML): Enables users to insert, update, delete, and retrieve data from the database.
• Database Access Control, Integrity, Concurrency, Recovery, Catalog, and Views: Provide controlled access, security, integrity, concurrency, recovery, and user-accessible database catalogs; simplifies data for users.

Fundamental Database Concepts - DBMS Components

• Hardware: The computer equipment.
• Software: The DBMS, the operating system, and application programs.
• Data: All the information stored in the system.
• Procedures: The specific processes and rules for handling tasks within the DBMS.
• People: Include data/database administrators, database designers, application developers, and end-users.

DBMS vs. Flat File

• DBMS: Supports Multi-user access, designed for small and large businesses, removes redundancy and integrity issues, expensive but low total cost of ownership in the long term, easy to implement complex transactions.
• Flat File: Does not support multi-user access, limited to small systems, has redundancy and integrity issues, is cheaper, no support for complicated transactions.

Fundamental Database Concepts - Advantages & Disadvantages

• Advantages of the Database Approach: Minimizes data redundancy, maintains data consistency, allows data sharing, improves security and integrity.
• Disadvantages of the Database Approach: Complex structure, high cost, reduced performance, and higher impact of a failure.

DBMS Advantages (Additional Info)

• Efficient Storage and Retrieval: Employ various techniques and powerful functions.
• Balances Applications: Acts as an efficient handler.
• Uniform Management: Provides uniform administration procedures for data management.
• Data Integrity and Security: Implements integrity constraints to control access.
• Controlled Access: Schedules concurrent access, ensuring only one user can access the same data at a time.
• Reduced Application Development: Application programmers are not exposed to data representation details.

DBMS Disadvantages (Additional Info)

• High Hardware and Software Costs: Significant investment is required.
• Complex Systems: Often requiring specialized training for users.
• Potential for Data Damage or Corruption: All data integrated into a single database can potentially create vulnerabilities.
• Data Loss: Multiple users simultaneously using the same system at the same time may lead to data loss if the process is not appropriately handled.
• Limitations in Calculations: DBMS may not be suited for complex calculations.

Spatial Database Concepts

• Definition: Contains information about spatial location, topological relationships, shape of geographic features, and the attributes of the data.

Spatial Database Characteristics

• Spatial Database System: A database system.
• Spatial Data Types (SDTs): Included in the data model and query language.
• Spatial Indexing and Join Algorithms: Supported in the implementation for efficient operations.

Geographic Database - Types and Functions

• Attempts to Define Geographic Data Types: Various attempts to standardize geographic data representation and processing using international standards (ISO) and the Open Geospatial Consortium (OGC).
• GIS Community Efforts: Defined core geographic types and functions that are used in DBMSs and are accessible using the SQL language.

Geographic Database - Geometry

• Geometry Class: The root class for geometric objects.
• Spatial Reference: Associated with a coordinate system (e.g., UTM, WGS1984).
• Subtypes: Includes Point, Curve, Surface, and Geometry Collection.
• Relationships: The hierarchy shows how geometries combine from other types.

Geometry Class Hierarchy

• Diagram: A hierarchical visual representation illustrating the relationships among geometric types. (Reference: after OGC)

Boolean Operations

• Spatial Relationships: A set of Boolean operators to test spatial relationships between geometric objects.
  • Equals
  • Disjoint
  • Intersects
  • Touches
  • Crosses
  • Within
  • Contains
  • Overlaps
  • Relate

Boolean Operations (examples)

• Examples illustrate the specific operations and their applications.

Advantages of Spatial Database vs. Traditional File System

• Data Consolidation: Reduces redundancy through central data storage; simplifies maintenance and reduces data duplication or replication.
• Application Independence: Data is independent, allowing easier application evolution and simultaneous usage.
• Ease of Data Sharing and Management: Provides easy and streamlined data sharing across applications and between different users.
• Data Access Security and Standards: Improved data security and access controls.

Disadvantages of Spatial Database vs. Traditional File System

• High Costs: The cost of acquiring and maintaining DBMS software can be substantial.
• Complexity to Manage: Implementing and properly managing a DBMS adds complexity to managing data, especially in projects involving small numbers of data inputs.
• Performance for Single Users: Single-user performance can sometimes be better when using traditional file systems, especially when dealing with complex data types.
• Database Size Issues: Modern geographic databases are often increasing in size and complexity.

Database Management Systems

• Definition: Software for organizing, storing, and accessing data efficiently and effectively.
• Small Databases: Small databases can often be stored simply and efficiently.
• Large Complex Databases: Large databases require specialist DBMS software for database management and integrity.

DBMS Provides

• Data Model, Indexes, Query Language, Security, Security, Controlled Update, Backup and Recovery, Database Administration Tools, and Application Programming Interfaces (APIs): List various functionalities provided by DBMS systems.

DBMS Provides (detailed aspects)

• Data Load: Tools to load data into databases, often for standard formats (character, numbers, dates) or via custom software.
• Indexing: Data structures (indexes) to accelerate searches across all database data types.
• Query Language: Provides standard query language like SQL for database interaction and query handling.
• Security: Controls access to all or part of the database to safeguard data.
• Controlled Update: Through transaction management, ensuring consistent updates in a multi-user environment.
• Backup and Recovery: Utilized to protect data from system failures and provide recovery options.
• Database Administration Tools: Help administrators manage database schema, performance indexing, and user access rights.
• Applications: Standard and general-purpose tools for creating, using, and maintaining databases.
• Application Programming Interfaces (APIs): Customizable interfaces to allow advanced integration of application programming languages for additional function enhancements.

DBMS and GIS

• DBMS Integration In GIS: Virtually all large-scale GIS databases are based on DBMS technology.
• DBMS Integration with GIS Software: Most GIS vendors either integrate the DBMS within their product or provide an interface for DBMS integration to enhance functionality.

Types of DBMS

• Classification: Classified based on how data is stored and manipulated.
• Relational (RDBMS): Contains a set of tables and records of data attributes describing the objects under study. Over 95% of DBMS data are stored this way. Relational databases were primarily developed for handling business applications.
• Object (ODBMS): Stores complete objects directly in the database which addresses weaknesses of RDBMS, including support for rich data types.
• Object-Relational (ORDBMS): Hybrid systems combining features of RDBMS and ODBMS, designed to handle rich data and complex objects found in databases like those in GIS systems.

Geographic ORDBMS

• Extension: Supports geographic data types and functions through the addition of those functions described further in later slides.

Geographic ORDBMS - Supports and Functions (various aspects)

• Query Parser: The engine interprets SQL queries.
• Query Optimizer: Optimizes the software query to efficiently handle geographic queries in the database software.
• Query Language: Supports geographic types and functions (e.g., finding polygons that touch each other).
• Indexing Services: Extends standard indexing to support multidimensional data formats (e.g., x, y, z coordinates).
• Storage Management: Handles large volumes of geographic records and their specialized storage structure.
• Transaction Services: Extended to support long transactions commonly occurring in geographic operations.
• Replication: Supports replicating databases to handle geographically diverse systems or distributed users, properly handling reconciliation.
• Examples for Query Optimizer: Specific example query use cases and options are provided demonstrating how to use database search algorithms.

Applications of Database Management

• Common application areas include industries like banking, manufacturing, finance, universities, and airlines. There are many geographical database use cases in administration, water resources, and the cadastre (land records).

Users in a DBMS Environment

• Application Programmers: Write programs in various programming languages to interact with databases.
• Database Administrators: Responsible for managing the entire DBMS system.
• End-Users: Interact with the database, conduct operations like data retrieval, updates, and deletion.

Popular DBMS Software

• A list of popular software tools for DBMS implementation.

Alternative to Using DBMS Systems

• Circumstances in which a more simple approach is sufficient and recommended over implementing a full database management system (example: cases in which the budget or expertise is lacking).

This quiz covers Unit 6 on spatial databases, focusing on fundamental database concepts and the role of Database Management Systems (DBMS) in modern information systems. It explores the transition from file-based systems to a more integrated database approach, addressing common issues such as data redundancy. Test your knowledge on these essential topics and their practical applications.