note 108315 deleted from mongocollection.ensureindex by derick

Note Submitter: coffee dot stone at gmail dot com ---- be careful when using ensureIndex('loc'=>'2d') for example, if the data structure of loc is array('lng'=>120, 'lat'=>-30), when it is saved into database, its structure will be ['lat':-30, 'lng':120], it is because the array in PHP is the ordered map, not the order of literal in your code. so the 2d-index is mapped as (lat, lng). when you find your location with (lng, lat), the wrong results are returned. be careful