[postgis-users] data base structure for holding climate data

[Brent Wood]

> > I'm assuming also you will do the same for lat lon - store them as
> > postgis geom point types to take advantage of the postgis spatial
> > functions.
> 
> Obe, How is storing lat lon as geom points different from reading  
> them into postgis as simple xy coordinates?

Hi Kirk,

You can store coords as simple XY coords as Postgres datatypes, but _NOT_
POstGIS. 

Postgis can only store very specific spatial datatypes, including points, which
have 2 (or 3 coordinates), XY & optional Z, along with a SRID representing
projection/datum. (a SRID of -1 means unknown- but is still has a value)

Storing such data as points (geometric objects) means you can use them with all
the Postgis geometry functions, otherwise you are storing it as a number (or
two numbers), and can only use simple numeric functions. So as a point you can
use point-in-poly, distance, transform, etc., functions which cannot be applied
to simple numeric data.


Cheers,

  Brent