<jonathanmoules@...> writes: > > I need to deploy four stand-alone laptops with > a basic GIS (data viewing only) and have chosen QGIS for this. The data > held is for the entire county of Warwickshire, and one of the datasets > I need to put on there is MasterMap. Specifically the datasets I'm using > are:Topographic line: 3.7 million featuresTopographic Area: 1.3 million featuresCartographic Text: 250,000 featuresGiven the dataset size, obviously the first > choice is a database, but as these are stand-alone laptops that must have > the simplest setup possible (they're going to be used out in the field > away from tech-support) I've ruled that option out.I tried shapefile's but it turns out that
Hi, I think that the best method for browsing that much of vector data would be to use OpenJUMP or copy the way how it handles PostGIS layers in to QGIS. What is special with the OpenJUMP native PostGIS driver is that PostGIS layers are dynamic. Only the features from withing the map view are queried from the database. They are cached for some time but previously used features are thrown away periodically which keeps the memory consumption small. You can have millions of features in the database but when you zoom in OpenJUMP is having only a handful of features on the layer. Application makes a new query when user is panning so all the millions of features are available when needed and the system is practically as fast as PostGIS is. What the user must do is to set scale limits for the database layers. It does not make sense ever to show million features on a map. When zoomed out the application must switch off the detailed layer and show some genaralised layer instead. That could be done by making such a into PostGIS and addind that as another layer into GIS project. -Jukka Rahkonen- _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
