[postgis-users] Massive Lidar Dataset Datatype Suggestions?

[Paul Ramsey]

On 13-Nov-04, at 12:34 PM, collin wrote:

> I am trying to figure the best setup for storing, extracting and 
> processing this dataset.  btw, it is a smallish dataset. We will be 
> processing 2 billion+ point projects in the near future.

The key here is "the best setup for storing, extracting and 
processing". You are talking about non-trivial amounts of data and 
processing tasks, so the decisions you make about storage will have 
large downstream effects. The "right decisions" are dictated by what 
you are actually going to *do* with the data.  How are you going to be 
querying it?  What variables and variable combinations will you be 
using?
Do you really need to store every point as a separate row, for example? 
  One "easy" way to cut down your storage and index size would be to 
store your LIDAR points as MULTIPOINT patches. Simply cut up your 
working plane with an arbitrary grid system and patch the points 
together based on their x/y values and what grid cell they fall into.  
Depending on the importance of the extra point attributes for your 
downstream processing plans, this simplification might be a very smart 
one.
Really, the key is what your downstream processing regime will be. 
Regardless, get the LWGEOM working, HWGEOM is really inappropriate for 
point data.
Paul