FUNDAMENTAL OF GIS & REMOTE SENSING (GLS280) CHAPTER 3
GIS DATABASE
Lecture outline At the end of this lecture, student should be able to: • Understand the meaning of Database • Define different type of Database
Introduction • Geographic database are simply databases containing geographic data for a particular area and subject. • A geographic database is a critical part of an operational GIS both because of the cost of creation and maintenance, and because of the impact of a geographic database on all analysis, modelling, and decision-making activities. • Databases can be physically stored in files or by using specialist software programs called DBMS. • today., most large organizations use a combination of files and DBMS for storing data assets.
Data Management • Data management functions necessary in any GIS system to Facilitate the storage Organization retrieval the data - database
• In GIS, database was created to manage a large proportion of data • Database is a set of structured data or collection of related data • DBMS – organized data in computer database
Definitions • Database – an integrated set of attributes on a particular subject • Geographic (=geospatial) database – set of attributes on a particular subject for a particular geographic area • Database Management System (DBMS) – software to create, maintain and access databases
Cont.. Definition: • A database can be thought of a set of data on a particular subject • A database is an organized collection of data. It is the collection of tables, queries, reports, views and other objects. • The data is typically organized to model aspects of reality in a way that supports processes requiring information.
Cont.. A geographic database is a critical part of operational GIS because -
Cost of creation & maintenance
-
The impact of geographic database on all analysis, modelling & decision making activities.
The Database in GIS • The central data integrator for GIS is the database. • Database in GIS is a simple concept - a list or table of data arranged as rows and columns. • Rows are the records, or each observation entered into the database. • Columns are called fields, which present the attributes or descriptions of each record.
Rows and columns table • Tabular information is the basis of geographic features, allowing you to visualize, query, and analyze your data.
• In the simplest terms, tables are made up of rows and columns, and all rows have the same columns. In ArcGIS, rows are known as records and columns are fields. • Each field can store a specific type of data, such as a number, date, or piece of text.
A GIS links attribute and spatial data
• Attribute Data
• Map Data
• Flat File or DBMS
• Point File
• Relationships
• Area File
• Topology Table
• Topology Type
• Line File
Sample of database created in GIS system
Rows and columns table