I have a database full of point data. When our user stops at a certain
lat/lon, how do I find the closest point in our database?
We have at least 10,000 points, maybe a lot more so the search has to be
efficient, but I have not found a way. It seems a little surprising
considering how common this query must be.
The obvious way is to scan the entire table and find the closest point. Let's
say our user stops at (40,70), I could do this:
SELECT * FROM foo
ORDER BY distance(point_geom, GeomFromText('POINT(70.0 40.1)', 4326))
LIMIT 1
When I run this through EXPLAIN ANALYZE, it shows a full-table scan. Is there
a way I can use a GIST or is there some other way to speed it up?
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