This section of the help documents concepts involved with the structure and content of the data base.
The data base is topologically structured and geographically indexed.
The topological structure ensures that object relationships are maintained. For example, moving a point which is defined in a line will modify the shape of the line. If that line is defined in a polygon, the shape and area of that polygon will also be modified. This concept applies throughout the system.
The geographical indexing maximises the speed of operation allowing rapid screen regeneration and the ability to find objects efficiently. It also permits three dimensional models of virtually unlimited size to be processed, subject to hardware limitations.
Data Base Objects
The data base may contain the following object types.
- Points
- Lines
- Primary and Secondary Alignments
- Long Sections
- Cross Sections
- Section Markers
- Corridors of Interest
- Polygons
- Text
By definition, polygons consist of lines and lines consist of points.
The following objects are special types of line objects
The following is a combination of arc and spiral objects.
Each of these object types may have particular attributes associated with them Select the appropriate topic for further information.
Data Base Files
Refer to the
topic for information on the various files created and/or used by the data base.