1. UNIT 3 – MODULE 4: Database Management

2. INTRODUCTION Managing data is a critically important function. It enables strategic searching & manipulation of data that would manually take large amounts of time. GIS has two data types that requires management: spatial & attribute data. Credit: C. Jones, GIS & Computer Cartography, 1997

3. ADVANTAGES There are many benefits to having a computerized database: – Can be utilized for other purposes (e.g. marketing). – Reduction in redundancies (unnecessary data duplication). – Easy to maintain (e.g. automated updating). – Can quickly sift through information based on multiple parameters. Credit: Alaska Department of Natural Resources

4. DATABASE CREATION There are four major steps for database creation: 1.Data Investigation – consider the type of data you want for a database (e.g. what are you trying to prove/show with the data?). No GIS software required. 2.Data Modeling – forming a conceptual model by assessing entities & attribute data characteristics (i.e. how will data be linked?). No GIS software required. 3.Database Design – creating a user-friendly database design. Dependent on GIS software to be used and data model chosen. 4.Database Implementation – infusing the database with attribute data by a specific procedure.

5. SPATIAL & ATTRIBUTE LINK Relationship between databases and GIS will vary. For example: a simple raster GIS will not require a database. One relationship option is having attribute file data separated from a raster image. Most vector GIS utilize a hybrid approach, where spatial data is stored within the GIS data structure, and attribute data is stored in a database management system (DBMS). All spatial & attribute data could also be found within the same DBMS. Bottom line: there are options.

6. CONCLUSION It is important to understand how information is stored within a GIS. This enhances your ability to manipulate data, which assists in what you’re trying to show or resolve. It also allows you to better understand how data-related errors might have occurred. Credit: ESRI