Geolocating the Nearest Pub
Learn about kNN search and indexing in kNN search.
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kNN search
To implement a
kNN search in PostgreSQL, we need to order the result set with a distance operator, written <->. Here’s the full SQL for searching the pubs near a known position:
select id, name, posfrom pubnamesorder by pos <-> point(-0.12,51.516)limit 3;
With this geolocation, we obtain the following nearby pubs:
id │ name │ pos
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