create index on aH.uid > db.testing_ah_array_path_new.find({'aH.sm':'dominik','aH.uid':{'$gte':1, '$lte':1000}}).explain() { "cursor" : "BtreeCursor aH_uid_1", "isMultiKey" : true, "n" : 276, "nscannedObjects" : 124565, "nscanned" : 124565, "nscannedObjectsAllPlans" : 124667, "nscannedAllPlans" : 124667, "scanAndOrder" : false, "indexOnly" : false, "nYields" : 1, "nChunkSkips" : 0, "millis" : 809, "indexBounds" : { "aH.uid" : [ [ 1, 1.7976931348623157e+308 ] ] } , } On the other hand, when changing the '$lte' and '$gte' order > db.testing_ah_array_path_new.find({'aH.sm':'dominik','aH.uid':{'$lte':1000,'$gte':1}}).explain() { "cursor" : "BtreeCursor aH_uid_1", "isMultiKey" : true, "n" : 276, "nscannedObjects" : 276, "nscanned" : 276, "nscannedObjectsAllPlans" : 378, "nscannedAllPlans" : 378, "scanAndOrder" : false, "indexOnly" : false, "nYields" : 0, "nChunkSkips" : 0, "millis" : 2, "indexBounds" : { "aH.uid" : [ [ -1.7976931348623157e+308, 1000 ] ] } , } In both cases, upper and lower bound should be shown as set to 1 and 1000 respectively by explain()