1. DATA MANAGEMENT IN GIS SPATIAL (GEO) DATA MODELS
NON SPATIAL (RELATIONAL) DATA MODELS
GEO-RELATIONAL MODEL
By Prof. V L. Swaminathan

2. DATA COMPONENTS IN GIS G E O G R A P H I C D A T A T1 T2
Temporal
Dimension
LOCATIONAL DATA
(Spatial)
NON-LOCATIONAL
(Description)
T1 T2
Measured x-y
Topological
Relation
Var Class Val Name
Point Line Poly Grid Net.
Soil Sand
Fine
Coarse

3. SPATIAL DATA MODELING DIGITAL MODEL GIS DATABASE MODEL MAP RASTER
REAL WORLD
ELLIPSOID
DIGITAL
MODEL
GIS DATABASE
MODEL
SPHEROID
ANALOG
MODEL
MAP
RASTER
VECTOR

4. VECTOR SPAGHETTI STRUCTURE11 31 6 15
(0,0) X
AXIS Y
Feature No Location
Point x,y (Single Point)
Line x1,y1;x2,y2;...xn,yn
Polygon x1,y1;x2,y2;...xn,yn
Polygon x1,y1;x2,y2;...xn,yn

5. VECTOR SPAGHETTI : Critique-1
Feature No Location
Point x,y (Single Point)
Line x1,y1;x2,y2;...xn,yn
Polygon x1,y1;x2,y2;...xn,yn
Polygon x1,y1;x2,y2;...xn,yn 11 31 6 15
(0,0) X
AXIS Y
CAPTURES LOCATIONS ACCURATELY BUT:
SHARED BOUNDARIES OF POLYGON 31 & 15 CAPTURED MORE THAN ONCE.
IN REALITY SUCH REPETITIONS WILL BE MANY.
PROBLEMS OF INTEGRITY, AND REDUNDANCY IN DATABASE

6. VECTOR SPAGHETTI : Critique-2
Feature No Location
Point x,y (Single Point)
Line x1,y1;x2,y2;...xn,yn
Polygon x1,y1;x2,y2;...xn,yn
Polygon x1,y1;x2,y2;...xn,yn 11 31 6 15
(0,0) X
AXIS Y
POLYGON 31 IS INCLUDED IN 15 . LINE 11 AND POINT 6 ARE ALSO WITHIN POLYGON 15.
IN REALITY SUCH RELATIONSHIPS ARE MANY.
SPATIAL RELATIONSHIPS HAVE TO BE COMPUTED GEOMETRICALL AND INFERRED
IMPLICATIONS ON COMPUTATIONAL EFFICIENCY

7. VECTOR TOPOLOGY STRUCTURE1 2 5 3 4 6 7 8 9 10 11
NODE
LINK
POLYGON
LINK# R-POLY L-POLY NODE-1 NODE-2
NODE# X_COORD Y_CORD

8. VECTOR TOPOLOGY STRUCTURE : CRITIQUE -12 5 3 4 6 7 8 9 10 11
NODE
LINK
POLYGON
LINK# R-POLY L-POLY NODE-1 NODE-2
NODE# X_COORD Y_CORD
CAPTURES CO-ORDINATES ONLY ONCE
PROBLEMS OF REDUNDANCY AND INTEGRITY MINIMIZED

9. VECTOR TOPOLOGY STRUCTURE : CRITIQUE -21 2 5 3 4 6 7 8 9 10 11
NODE
LINK
POLYGON
LINK# R-POLY L-POLY NODE-1 NODE-2
CAPTURES SPATIAL RELATIONSHIPS EXPLICITLY
ASSOCIATION AMONGST THE SPATIAL FEATURES
CONNECTIVITY

10. VECTOR TOPOLOGY STRUCTURE : CRITIQUE -31 2 5 3 4 6 7 8 9 10 11
NODE
LINK
POLYGON
LINK# R-POLY L-POLY NODE-1 NODE-2
ASSOCIATION
FOR FINDING POLYGONS SURROUNDING 3, SEARCH THROUGH THE LIST
LOOK FOR LINKS BOUNDING THE POLYGON-3
LOOK FOR ASSOCIATED R-POLY & L-POLY

11. VECTOR TOPOLOGY STRUCTURE : CRITIQUE -41 2 5 3 4 6 7 8 9 10 11
NODE
LINK
POLYGON
LINK# R-POLY L-POLY NODE-1 NODE-2
CONNECTIVITY : NODE-7 & NODE-2
LOOK FOR LINKS EMNATING FROM NODE-7 i.e 9, 11,10
FOCUS ON ONE LINK(i.e. 9) AND LOOK FOR ASSOCIATED NODES (i.e 6)
LOOK FOR LINKS EMNATING FROM THIS NODE (i.e. 8,7)
CONTINUE THE PROCESS TILL NODE 2 IS REACHED FOR ALL THE PASSES

12. VECTOR TOPOLOGY STRUCTURE : CRITIQUE -51 2 5 3 4 6 7 8 9 10 11
NODE
LINK
POLYGON
LINK# R-POLY L-POLY NODE-1 NODE-2
NODE# X_COORD Y_CORD
BY EXPLICITLY CAPTURING SPATIAL RELATIONSHIPS (i.e. TOPOLOGY
GEOMETRIC COMPUTATION PROBLEM IS TURNED INTO SEARCH PROBLEM

13. RASTER GRID STRUCTURE 1 2 3 4 File Structure: 0 0 0 0 0 0 0 1 2 3 4
File Structure:
Row Column Value
Row Column Value

14. RASTER GRID : Critique-1 1 2 3 4
LINE AND POINT NOT REPRESENTED:
SEPEARATE LAYERS REQUIRED FOR
OVERLAPPING FEATURES
POLYGONS, POINTS AND LINES

15. RASTER GRID : Critique-2 1 2 3 4
0’S AND 1’S REPEATED MANY TIMES UNNECESSARILY
REDUNDANCY OF DATA STORAGE
IMPLICATIONS ON STORAGE
VOLUME
SOLUTION
RUN LENGTH ENCODING
ROW COLUMN VAL

16. RASTER GRID : Critique-2 1 2 3 4
POLYGON 2 NOT REPRESENTED:
GRID SIZE HAS TO BE SMALLER IN ORDER TO REPRESENT FEATURES ACCURATELY
- IMPLICATIONS ON STORAGE VOLUME
OR HAVE VARIABLE SIZE OF GRID OVERLAY :
QUAD-TREE

17. QUAD-TREE STRUCTURE RASTER QUADTREE
AREA RECURSIVELY DECOMPOSED INTO REGULAR SHAPED GRIDS OF SMALLER & SMALLER SIZE TILL SMALLEST GRID REPRESENTS HOMOGENEOUS REGION
REQUIRES LESS STORAGE THAN RASTER AS NUMBER OF GRIDS WILL BE LESS
GRIDS COULD BE TRIANGLES, SQUARES OR HEXAGON
SQUARES COMMONLY USED BECAUSE ORIENTATION PROBLEM COMES IN FOR OTHER SHAPES

18. QUAD-TREE STRUCTURE : CRITIQUE-1B C D BA BC
BAC
BAD
BCA
BCB
BCC
RESULTS IN TREE STRUCTURE (PARENT CHILD RELATION SHIPS AMONGST THE CELLS) FOR STORAGE AND RETRIEVAL

19. QUAD-TREE STRUCTURE : CRITIQUE-2B C D BA BC
BAC
BAD
BCA
BCB
BCC
REQUIRES LESS STORAGE THAN RASTER AS NUMBER OF GRIDS WILL BE LESS
GRID B WILL BE REPRESENTED BY ONLY 5 CELLS AGAINST 16 IN RASTER MODE

20. QUAD-TREE STRUCTURE - CRITIQUE-3B C D BA BC
BAC
BAD
BCA
BCB
BCC
AMENABLE TO VARIABLE SCALE DATABASE HANDLING
FACILITATES DISTRIBUTED DATABASE HANDLING OF LARGE DATABASES
VARIOUS OTHER QUADTREE APPROCHES

21. QUAD-TREE STRUCTURE - CRITIQUE-4
VERY SENSITIVE FOR CO-ORDINATE TRANSFORMATION
TRANSLATION
ROTATION
ENTIRE TREE STRUCTURE HAS TO BE RE-WORKED ON AFFECTING THESE TRANSFORMATIONS

22. QUAD-TREE STRUCTURE - CRITIQUE-5
MANY OTHER APPROCHES
PM QUADTREE
SUB-DIVISION BASED ON DECOMPSITION OF BOUNDARY EDGES AND VERTICES
ORIGINAL VECTOR STRUCTURE AND TOPOLOGY IS MAINTAINED, THUS GIVES BEST OF BOTH WORLD
POINT QUADTREE
SUB-DIVISION BASED ON LOCATION OF ORDERED DATA POINTS RATHER THAN REGULAR SPATIAL DECOMPOSITION
MX , PR, AND MANY MORE...

23. SPATIAL DATA MODELS - CRITIQUE
MODEL AFFECTS ALL ASPECTS OF GIS EFFICIENCY
DIFFERENT APPROACHES STRIVE TO REALISE IDEAL REPRESENTATION OF FEATURES IN GIS VIS-A-VIS THE ASPECTS GIVEN IN TABLE
NONE OF THE APPROACHES GIVES IDEAL SOLUTION

24. NON SPATIAL DATA HANDLING IN GIS
BASED ON DATABASE MANAGEMENT SYSTEM (DBMS) CONCEPTS

25. DATABASE MANAGEMENT SYSTEM (DBMS)
STRUCTURED/ SYSTEMATIC, SHARABLE, NON-REDUNDANT STORAGE OF DATA
DBMS
STANDARD S/W TOOL FACILITATING ALL ASPECTS OF DATABASE MANAGEMENT VIZ INPUT, STORAGE, RETRIEVAL & PRENENTATION

26. PURPOSE OF DBMS APPROACH
REDUCED DATA REDUNDANCY - VOLUME, CONSISTENCY, INTEGRITY, QUALITY
DATA DICTIONARY - SELF DESCRIPTIVE, DOCUMENTED STORAGE
PROGRAM & DATA INDEPENDENCE - INDEPENDANT CHANGE OF USER PROGRAM AND/OR DATA STORAGE FORMAT ( ITEMS, FILES, DEVICE)
TRANSPARENCY - USER FREE FROM BOTHERATIONS OF INTERNAL STORAGE INTRICACIES
MULTIPLE USER VIEWS
STORED
DATABASE
(INTERNAL
VIEW)
CONCEPTUAL
VIEW
DBMS
EXTERNAL
VIEW- A
VIEW- B
USER- A
USER- B
USER- C
USER- D

27. DBMS TYPES (MODELS) - HEIRARCHIAL
RIGID VS HORIZONTAL RELATIONS
OCCURANCES CAN NOT BE CHANGED
COUNTRY
STATE
REGION
CITY
TOWN

28. DBMS MODELS- NETWORK OCCURANCES CAN NOT BE CHANGED COUNTRY STATE
REGION
CITY
TOWN

29. DBMS MODELS- RELATIONAL
COUNTRY
STATE
REGION
CITY
TOWN C1 C2 C3 S1 S2 S3 R1 R2 R3 T1 T2
FLEXIBLE RELATIONSHIPS, OCCURANCES
REDUNDANCY
COUNTRY STATE
C1 S1
C2 S2
C3 S3
.. ..
STATE CITY
S1 C1
S1 C2
S3 C3
STATE TOWN
S3 T1
S3 T2
REGION CITY
COUNTRY REGION
C3 R1
C3 R2
C2 R3
REGION TOWN
STATE REGION
.. ..

30. GIS-VS-DBMS TWO WAYS TO USE DBMS CONCEPT IN GIS
TOTAL DBMS SOLUTION - ALL DATA OPERATIONS IN DBMS ENVIRONMENT
PROBLEMS
VARIABLE LENGTH OF RECORDS FOR CO-ORDINATES
INFINITE NUMBER OF RELATIONSHIPS AMONGST THE SPATIAL OBJECTS
INTERNAL STRUCTURE TOO COMPLEX FOR DBMS'S TO PROVIDE TRANSPARENCY
MIXED SOLUTION - GEO RELATIONAL
SOME DATA ELEMENTS (ATTRIBUTES, ENTITY RELATIONSHIPS) IN DBMS (INFO,DBASE,ORACLE, INFORMIX)
SOME DATA (LOCATIONAL) DIRECTLY FROM FILES BECAUSE DIFFICULT TO HANDLE IN DBMS MODEL
SECOND METHOD GEO RELATIONAL USED IN GIS

31. GEO RELATIONAL MODEL IN GISP1 P2 P3 P4 N1 N2 N3 N4 N5
GEO DATA IN
PROPRIETORY FORMAT - HIDDEN FROM USERS
NON-SPATIAL DATA IN RELATIONAL (RDBMS) - ACCESSIBLE
ARCS
ID CO-ORD A A A
POLYGONS
ID ARCS
P1 A1,A2,A3
P2 A2,A7,A5,A6
P3 A3,A5,A4
NODES
ID CO-ORD
N1 X,Y
N2 X,Y
N3 X,Y
ARCS
ID L-POLY R-POLY FNODE TNODE LEN DESCR ..
A1 P N N
A2 P P N N
POLYGONS
ID AREA PERI DESCR POP .. P P

32. Thank you