Spatial indexing in mnesia

Hal Snyder <>
Thu Jan 4 18:29:08 CET 2001


David Gould <> writes:

> Right, is that the silver cover edition, or an earlier one? Mine is
> at work and I am not. Anyway, about 20 pages + or - from there is
> the paper by Antonin Guttman defining R-Trees which as far as I last
> knew are the prefered spatial index type.
> 
> Funny thing: at Illustra (and later Informix), I worked with a guy
> named Tony on some memory leaks and other integration bugs (we had a
> difficult runtime environment) in the spatial index code, and as
> sometimes happens when one is fixing someone elses bugs, I was kinda
> grumpy about it. "Who wrote all this cruft, why do we let this kinda
> slop get checked in" and so forth although it wasn't really that
> bad. It must have been about a year later when I tumbled to the fact
> that "Tony" was short for "Antonin". Sheesh. I wish I could say I
> was smarter now and wouldn't do that again...

A little OT maybe, but BTW we have been using PostgreSQL r-trees to
locate nearest service provider - customer dials 800 number for a
retail chain, we get long/lat from his number, look up nearest store
in (r-tree indexed) database, and connect. We even optimized the
search by preloading spatial data sorted in Hilbert curve order.

The algorithms are subtle but not extremely lengthy - I bet the whole
thing could be done nicely in Erlang/mnesia. Heck, maybe you could
even use Erlang for some of the telephony...




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