[postgis-users] Re: gps points to postgis

[Yves Moisan]

Hi,

Without knowing much about the limits of vertices in a linestring w/r to postGIS, I would be inclined to think of your GPS points as "points".  I think you'd better try to define some other programming logic to "turn" those GPS points into a linestring on the fly.  Maybe a stored procedure (or a Python script ?) taking the result of a query (that would happen to return your 8500 points) and returning a linestring object ?

This is a very interesting issue for a number of people.  For example, I would like to be able to generate "trajectories" from an arbitrary number of points.  That trajectory could be a line showing water quality data taken downstream that would cover 2 or three rivers, for example.  The set of points of interest could be user selectable.  I could probably also report some stats on the set of points making up my trajectory, in which case do we need a linestring or some other object that could be rendered as a linestring for viewing/mapping purposes, but that could also be worked upon through a programming language, be it SQL or Python.  My point is that points should remain points, in my view, as far as the database is concerned.  Whether some metadata is attached to those points to easily put together a simple SQL query to return the whole set or some other aggregation mechanism is used to turn those points into a geographical/statistical feature of interest or how that should be done is the jist of the problem.  That is maybe an issue for a content mangement system ??

Cheers,

Yves Moisan
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