GI ScienceDatabase Management Systems

Nigel TroddCoventry University

GIS are INFORMATION systems

what is the role of databases?what do they do?how do they do it ?

databases...

... a body of related data stored in a structured manner

a body of unstructured dataa body of structured data

store & retrieve data efficiently

and …

check integrate manipulate

a DataBase Management System

a DBMS is

'a software system with capabilities to define data and their attributes, establish relationships among data items, manipulate the data and manage the data'

Stamper & Price (1990)

but

Spatial data are different

Putting the G

into an IS

how do databases store spatial data ?

Spatial data = attribute + geometry / topology

but

things are rarely simple

rdbms

e.g. dBase MS Access Oracle 9i

Codd’s laws

Storing spatial data: relational db

Storing spatial data: relational db

geodb

Summary

data, databases, dbms, geodbdatabase models

– flat file, O-O– relational dbms

tables (tuples)– linked by unique identifiers

efficient storage, effective retrieval