INTEGERATED DATA ANALYSIS
GIS model is the integrated data
model which is more closely integrated with the database management system than
in the hybrid system. The integrated data model approach is also described as
the spatial data base management system approach, with the GIS serving as the
query processor sitting on top of the database itself. The integrated data model
has a number of implications in terms of the special characteristics of spatial
data. From the data base viewpoint, it is possible to store both the
coordinates and the topological information required to characterise digital
cartographic elements using a design based on Codd's Normal Forms. (x, y)
coordinate pairs for individual vertices along line segments are stored as different rows in a data base table. To
achieve satisfactory retrieval performance it has been found necessary to store
coordinate strings in long or 'bulk data' columns in tables. Handling of large
spatial databases is the need to convert 2-D coordinate information into 1-D
spatial keys that can be stored as data base table columns. These can then be
indexed in the normal way and used for fast retrieval of map elements contained
within or overlapping a specified geographical search area.
There are two ways of storing
coordinate information as relational tables. The first records individual (x,
y) coordinate pairs and polygon terminator and vertices as individual atomic
elements or a row in a database. It is very difficult to search any element
because each element must be recomposed from its atomic format to grate whole
polygons or groups of polygons. The integrated GIS with which it can be
understood how a single database can be configured to certain separate files
for entities and attributes.GIS purpose are based on entities, attributes, and
the relationship between entities and attributes with respect to the locations,
temporal changes and both location and time. In the following sections, an
attempt is made to provide a preliminary study for creating object based data
models on the basis of entity-attribute relationships, location based
representations of spatio-temporal data, and time based representations of
spatio-temporal data and a combined approach of representing spatio-temporal
data.
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