[Loadstone] Two Questions

Shawn Kirkpatrick shawn at odyssey.cm.nu
Thu Nov 1 03:18:45 GMT 2007


Dave's explanation is basically correct. Points are matched by the id and 
userid fields, all other data can be changed.
There are approximately 111.325 kilometres per degree of latitude but that's 
not exact. That number would do for most calculations but if you want the 
exact number you have to do a bit of calculating since it changes slightly 
depending on the latitude value. You could probably look up the exact 
calculations if you need them on wikipedia, they have very good explanations 
on all this stuff.

On Wed, 31 Oct 2007, Michael O. Hanson wrote:

> First, when I import a database with overlapping points, I get a message
> telling me how many points were added, how many points were updated, and how
> many duplicate entries were ignored.  I understand what it means when points
> are added or duplicate entries are ignored.  What does it mean when points
> are updated?
>
> Second, how many miles are between one degree of latitude and another
> degree?  I understand the distance between degrees of latitude does not
> change the further you are north or south of the equator.
>
> Thank You,
>
>
> Mike Hanson
>
>
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