gistfile1.txt

> db.details.ensureIndex({name: 1});
> db.details.reIndex();
{
	"nIndexesWas" : 2,
	"msg" : "indexes dropped for collection",
	"nIndexes" : 2,
	"indexes" : [
		{
			"key" : {
				"_id" : 1
			},
			"ns" : "local.details",
			"name" : "_id_"
		},
		{
			"key" : {
				"name" : 1
			},
			"ns" : "local.details",
			"name" : "name_1"
		}
	],
	"ok" : 1
}
> db.details.find();
{ "_id" : ObjectId("4f29108c986f01257a5db1ba"), "name" : "uk", "metro" : { "city" : "United Kingdom", "state" : "UK" } }
{ "_id" : ObjectId("4f291091986f01257a5db1bb"), "name" : "ak", "metro" : { "city" : "United Kingdom", "state" : "UK" } }
{ "_id" : ObjectId("4f291095986f01257a5db1bc"), "name" : "bk", "metro" : { "city" : "United Kingdom", "state" : "UK" } }
{ "_id" : ObjectId("4f291099986f01257a5db1bd"), "name" : "ck", "metro" : { "city" : "United Kingdom", "state" : "UK" } }
{ "_id" : ObjectId("4f29109d986f01257a5db1be"), "name" : "dk", "metro" : { "city" : "United Kingdom", "state" : "UK" } }