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Multi-user and internet mapping. Multi-user environments. Simple file server solution, LAN (Novel, Windows network). View from everywhere, edit from one workstation. Special graphic database. Locking part of file, check out/check in. Spatial data server.
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Multi-user environments • Simple file server solution, LAN (Novel, Windows network) View from everywhere, edit from one workstation • Special graphic database Locking part of file, check out/check in • Spatial data server Based on relational database, locking, SQL • Web map server
Spatial data server What is the problem with the traditional divided system? • Difficult to maintain the consistency between graphical and attribute data. Two different I/O channel must be handled. • The hybrid solution can not utilize all the advantages of relational databases asdata security, distributed database, multi-user editing etc. • The multi-user editing capabilities of relational databases can not be used forgraphic data, separate solution must be developed for graphic data. • Conversion between different graphic data format is difficult.
Spatial indexing I. The aim of a spatial index is to make the spatial searches faster. By the help of the spatial index we can • Find objects covering a given point • Find objects overlapping a given area • Create spatial join between two spatial indeces (contains, within, intersects) • Combine geometries based on spatial position
Spatial indexing II. Minimal Boundary Rectangle (MBR) Multiple Entry Spatial Index (MESI)
file query html document, image, other file Internet map publication Basic situation Webserver Client browser http protocol Static image (jpg, png, gif) Other sample Third Image map sample <map name="minta"> <area shape="circle" coords="30,30 50,50" href="http://valahol> <area shape="rect" coords="70,40 90,60" href="http://mashol> <area shape="poly" coords="245,462,263,523,336,519,362,446" href="#"> </map> <img src=„kep.gif" height=545 width=804 usemap="#minta">
Data query html document, image Thin client Webserver Mapserver Client browser http protocol Spatial database e.g. ESRI IMS, UMN MapServer, Google Earth more examples sample
file query data file Thick client Webserver Client browser+ plug-in http protocol Spatial database e.g. SVG Viewer, Autodesk Express Viewer, Java Applet sample svg tutorial more examples
initialization data Combined solution Webserver Mapserver Client browser+ plug-in http protocol spatialdatabase e.g. Autodesk Map Guide, Mapserver + Java Servlet + Java Applet sample other sample