Per Jessen schreef:
Richard Lynch wrote:

OK, what is a 'geometry column' and what is a 'spatial index' ?
Imagine a single column combining both longitude and latitude.

Now imagine an index that "knows" about long/lat, and keeps
geographically "close" objects sorted in the index for you.

Including "knowing" about the 180 <-> -180 degree wrap-around.
(Or 360 === 0 wrap-around in the other geo-system.)

So when you ask for "theme parks near Zurich" your DB can answer in
milliseconds instead of minutes.

Thanks Richard - I thought Nathan was talking about an abstract concept,
not something "real". So, back the Nathans suggestion:
Back on the mysql side of things, try using geometry columns rather
than numerical primary keys, with spatial indexes.. it's a MASSIVE
performance upgrade (I've cut 5 second queries down to 0.005 by
using geo columns)

Is this worth a try?  Have others tried this?

I for one would really like to see a concrete example of this kind of
use of geometry columns and spacial indexes as an alternative to the stand
integer based primary keys.



/Per Jessen, Zürich


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