[postgis-users] Versioning

[Ben Madin]

I might not have the best solution, but for some use cases this is one  
of the key reasons we are using a database for GIS data. It isn't  
perfect, so any feedback would be considered in a positive light.

Every record has a start and end validity - the end being null for the  
most recent.

When new data is provided, we insert a new record, with the new start  
validity, and put in an end validity for the old record (we also  
record the user id who made the change)


This is a solution for the Multiple Areal Unit Problem for  
jurisdictional boundaries (at some level), so not a huge number of  
polygons, and for event data (as points)

Queries can then draw the appropriate polygon for the timing of the  
data set. I'm new to dealing with it, but obviously there are problems  
with some analyses where the boundary changes within the range of  
times in a query.

Actually, this might not be a very good solution at all, but has  
helped for now!

cheers

Ben


On 14/05/2009, at 4:26 AM, Juan Pedro Pérez Alcántara wrote:

> Sure, you right. I'm refering versioning in it's first meaning, that  
> is,
> history tracking.



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Ben Madin
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