> db.testcol.find().limit(7)
{ "_id" : "id1", "field" : [ { "age" : 23, "height" : 137 } ] }
{ "_id" : "id2", "field" : [ { "age" : 10, "height" : 137 }, { "age" : 24, "height" : 138 }, { "age" : 30, "height" : 141 }, { "age" : 10, "height" : 163 } ] }
{ "_id" : "id3", "field" : [ { "age" : 24, "height" : 163 }, { "age" : 26, "height" : 164 }, { "age" : 30, "height" : 130 }, { "age" : 10, "height" : 140 } ] }
{ "_id" : "id4", "field" : [ { "age" : 25, "height" : 163 } ] }
{ "_id" : "id5", "field" : [ { "age" : 10, "height" : 144 } ] }
{ "_id" : "id6", "field" : [ { "age" : 22, "height" : 169 }, { "age" : 26, "height" : 151 }, { "age" : 29, "height" : 171 } ] }
{ "_id" : "id7", "field" : [ { "age" : 30, "height" : 136 }, { "age" : 10, "height" : 142 }, { "age" : 27, "height" : 136 } ] }
> db.testcol.getIndexes()
[
	{
		"v" : 2,
		"key" : {
			"_id" : 1
		},
		"name" : "_id_",
		"ns" : "testdb.testcol"
	},
	{
		"v" : 2,
		"key" : {
			"field.age" : 1,
			"field.height" : 1
		},
		"name" : "field.age_1_field.height_1",
		"ns" : "testdb.testcol"
	}
]
> db.testcol.find({"field.age": 14, "field.height": 163}).explain()
{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "testdb.testcol",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"field.age" : {
						"$eq" : 14
					}
				},
				{
					"field.height" : {
						"$eq" : 163
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "FETCH",
			"filter" : {
				"field.height" : {
					"$eq" : 163
				}
			},
			"inputStage" : {
				"stage" : "IXSCAN",
				"keyPattern" : {
					"field.age" : 1,
					"field.height" : 1
				},
				"indexName" : "field.age_1_field.height_1",
				"isMultiKey" : true,
				"multiKeyPaths" : {
					"field.age" : [
						"field"
					],
					"field.height" : [
						"field"
					]
				},
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 2,
				"direction" : "forward",
				"indexBounds" : {
					"field.age" : [
						"[14.0, 14.0]"
					],
					"field.height" : [
						"[MinKey, MaxKey]"
					]
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"serverInfo" : {
		"host" : "MacBook-Pro.local",
		"port" : 27017,
		"version" : "3.4.2",
		"gitVersion" : "3f76e40c105fc223b3e5aac3e20dcd026b83b38b"
	},
	"ok" : 1
}