Speeding up mySQL SPATIAL select based on distance to coordinates - mysql

Question

I am trying to move our site over from using a Lat/Lng field (CHAR), when doing distance. This is how we currently do it:
SELECT ID,( 6371 * acos( cos( radians(52.35462) ) * cos( radians( glinks_Links.Latitude ) ) * cos( radians( glinks_Links.Longitude ) - radians(4.88227) ) + sin( radians(52.35462) ) * sin( radians( glinks_Links.Latitude ) ) ) ) AS distance FROM glinks_Links
WHERE
(
((Latitude BETWEEN (52.35462 - 40/69.0) AND (52.35462 + 40/69.0)) )
AND
(Longitude BETWEEN (4.88227 - 40/42.5) AND (4.88227 + 40/42.5))
)
HAVING distance < 40 ORDER BY distance
...and this comes back as
Showing rows 0 - 24 (1855 total, Query took 0.0288 seconds.)
Then another version that actually gives the "distance" back (as we want to sort by that, and only include the closest);
SELECT ID,st_distance_sphere(POINT(4.88227,52.35462), point_test) / 1000 AS distance FROM glinks_Links WHERE ( ((Latitude BETWEEN (52.35462 - 40/69.0) AND (52.35462 + 40/69.0)) ) AND (Longitude BETWEEN (4.88227 - 40/42.5) AND (4.88227 + 40/42.5)) ) HAVING DISTANCE < 100 ORDER BY distance LIMIT 100
Gives:
Showing rows 0 - 99 (100 total, Query took 0.0237 seconds.)
Then what seems to be the best:
SELECT *
FROM glinks_Links
where st_distance_sphere(POINT(4.88227,52.35462), point_test)/1000 <= 100
Showing rows 0 - 24 (3439 total, Query took 0.0015 seconds.)
The issue with that though - is that it doesn't provide me with the distance! What I want to do is query and grab the 100 closest. Is there a way I can do this, without compramising on the speed?

Answer 1

be sure you have proper composite index on
create index my_idx ON glinks_Links (Latitude, Longitude, ID)
And you don't need unuseful () for where condition (using AND)
SELECT ID,( 6371 * acos( cos( radians(52.35462) ) * cos( radians( glinks_Links.Latitude ) )
* cos( radians( glinks_Links.Longitude ) - radians(4.88227) ) + sin( radians(52.35462) )
* sin( radians( glinks_Links.Latitude ) ) ) ) AS distance
FROM glinks_Links
WHERE Latitude BETWEEN (52.35462 - 40/69.0) AND (52.35462 + 40/69.0)
AND Longitude BETWEEN (4.88227 - 40/42.5) AND (4.88227 + 40/42.5)
HAVING distance < 40
ORDER BY distance
for the second version
SELECT ID, st_distance_sphere(POINT(4.88227,52.35462), point_test) / 1000 AS distance
FROM glinks_Links
WHERE Latitude BETWEEN (52.35462 - 40/69.0) AND (52.35462 + 40/69.0)
AND Longitude BETWEEN (4.88227 - 40/42.5) AND (4.88227 + 40/42.5)
HAVING DISTANCE < 100
ORDER BY distance
LIMIT 100
you should use a composite index on
create index myidx ON glinks_Links (Latitude, Longitude, point_test, ID )