mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-09 16:09:22 +02:00
instead of int, change the calculation method to use the haversine formula which is more accurrate for short distances, added a grant to public for geo_distance and added a regression test. I will resubmit the earth distance stuff based on cube after 7.3 is released. Bruno Wolff III
42 lines
1.7 KiB
Plaintext
42 lines
1.7 KiB
Plaintext
---------------------------------------------------------------------
|
|
I corrected a bug in the geo_distance code where two double constants
|
|
were declared as int. I changed the distance function to use the
|
|
haversine formula which is more accurate for small distances.
|
|
I added a regression test to the package. I added a grant statement
|
|
to give execute access for geo_distance to public.
|
|
|
|
Bruno Wolff III
|
|
September 2002
|
|
---------------------------------------------------------------------
|
|
Date: Wed, 1 Apr 1998 15:19:32 -0600 (CST)
|
|
From: Hal Snyder <hal@vailsys.com>
|
|
To: vmehr@ctp.com
|
|
Subject: [QUESTIONS] Re: Spatial data, R-Trees
|
|
|
|
> From: Vivek Mehra <vmehr@ctp.com>
|
|
> Date: Wed, 1 Apr 1998 10:06:50 -0500
|
|
|
|
> Am just starting out with PostgreSQL and would like to learn more about
|
|
> the spatial data handling ablilities of postgreSQL - in terms of using
|
|
> R-tree indexes, user defined types, operators and functions.
|
|
>
|
|
> Would you be able to suggest where I could find some code and SQL to
|
|
> look at to create these?
|
|
|
|
Here's the setup for adding an operator '<@>' to give distance in
|
|
statute miles between two points on the earth's surface. Coordinates
|
|
are in degrees. Points are taken as (longitude, latitude) and not vice
|
|
versa as longitude is closer to the intuitive idea of x-axis and
|
|
latitude to y-axis.
|
|
|
|
There's C source, Makefile for FreeBSD, and SQL for installing and
|
|
testing the function.
|
|
|
|
Let me know if anything looks fishy!
|
|
|
|
A note on testing C extensions - it seems not enough to drop a function
|
|
and re-create it - if I change a function, I have to stop and restart
|
|
the backend for the new version to be seen. I guess it would be too
|
|
messy to track which functions are added from a .so and do a dlclose
|
|
when the last one is dropped.
|