The following query gets the last report (where latitude and longitude and secs are
<> 0) associated with the specified units:
SELECT reports.* FROM reports INNER JOIN units ON units.id = reports.unit_id WHERE reports.unit_id IN (1111, 1112, 1113) AND ( reports.id = ( SELECT reports.id FROM reports WHERE reports.unit_id = units.id AND reports.time_secs != 0 AND reports.latitude != 0.0 AND reports.longitude != 0.0 ORDER BY time desc LIMIT 1 ) )
This query took several minutes to run, and I was wondering if there is an optimization I can do to it.