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17cc78ef01
written a generic framework of rules that the contrib makefiles can use instead of writing their own each time. You only need to set a few variables and off you go. |
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| earthdistance.c | ||
| earthdistance.sql.in | ||
| Makefile | ||
| README.earthdistance | ||
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.