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I was studying geometric types and coordinates in SQL, in Postgresql more specifically, and I came across two operators, the operator <@> and the operator <->. What’s the difference between them? What’s the fastest?
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The operator <-> (distance between 2 objects), defined in Postgresql itself, is used with objects of a two-dimensional space.
The operator <@> (point <@> point), defined in the extra module "earthdistance", is used for the calculation of distances on the earth’s surface and takes into account the latitude and longitude of the points.
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The distance from the surface of the earth cannot be considered a two-dimensional space at the end of the day we use X and Y (lat lng)? From what I saw the <-> works with Point too, so which two methods would be the fastest?
– Eduardo Mior
According to the Terraplanists, yes.
– anonimo
It is that in the case of the Point we are not considering the altitude, only the latitude and longitude, then and if we put the earth in a straight plane it becomes a two-dimensional space, or the latitude and longitude cannot be considered as X and Y ?
– Eduardo Mior
The "earthdistance" module takes into account the curvature of the earth’s surface. Just remember that it is an approximation (consider the Earth as a perfect sphere), if you need more accuracy evaluate the use of Postgis.
– anonimo
In my case I need more optimization than precision, the accuracy for me is not important, I did some benchmarks comparing both Postgis and others and ended up not being very happy in the results, So in search of more agile solutions I ended up finding the distance operators, but I couldn’t find many explanations to tell the exact difference between them, all the documentation said was that they returned the distance between 2 points, but now it makes more sense. What I need is just sort by the nearest ones so I also don’t care about the unit of measure.
– Eduardo Mior