GI Science Database Management Systems Nigel Trodd Coventry University.

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