Re: How many views...

From: Holger Klawitter <lists(at)klawitter(dot)de>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: How many views...
Date: 2004-11-29 08:15:24
Message-ID: 200411290915.29686.lists@klawitter.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

> .... where sqrt(pow((lat1 - lat2),2) + pow((long1 - long2),2)) >= 50

I assume that you dont want to deal with distances > 1000km?!

> of the records that aren't in question anyways. How do you come to the
> lat/long values for the max difference? Is there a general formula for
> that?

You can problably resort to simplified formulas like this:

latitude: 1 degree ~~ 111km
longitude: 1 degree ~~ 111km * cos( reference latitude )

> (I hated math all my life ;-) )

The whole thing is likely to get tough for you then ;-)

Mit freundlichem Gruß / With kind regards
Holger Klawitter
- --
lists <at> klawitter <dot> de
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.2 (GNU/Linux)

iD8DBQFBqtqg1Xdt0HKSwgYRAmgJAJ9+PCiWIbnA2HR6QiGBlLXp9OQT6wCgg+gF
rL3xzK6UP9AUFsnWxpk4zoE=
=GQ0I
-----END PGP SIGNATURE-----

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Tino Wildenhain 2004-11-29 08:44:37 Re: How many views...
Previous Message Tom Lane 2004-11-29 07:36:10 Re: [HACKERS] Adding Reply-To: <listname> to Lists configuration ...