MongoDB : Unable to drop a Compound Index on a collection

Question

I have a compound index on my collection called people as shown below

 db.people.getIndexes()
[
        {
                "name" : "_id_",
                "ns" : "at.people",
                "key" : {
                        "_id" : 1
                }
        },
        {
                "_id" : ObjectId("521dd652a185d3defe301983"),
                "ns" : "at.people",
                "key" : {
                        "personname" : 1,
                        "email" : 1,
                        "sex" : 1,
                        "course" : 1
                },
                "name" : "personname_1_email_1_sex_1_course_1",
                "unique" : false
        }
]

I am trying to drop this index this way

 db.people.dropIndex({"personname_1_email_1_sex_1_course_1": 1})

But i am getting error message as

{ "errmsg" : "index not found", "ok" : 0 }

I also tried to drop the index by name

db.people.dropIndex( { "name" : "personname_1_email_1_sex_1_course_1" } )

I know i can drop the indexes on a collection in one shot using the below command

db.people.dropIndexes()

Please let me know how to resolve this ?

Answer 1

Pass the index name into dropIndex without putting it into an object:

db.people.dropIndex("personname_1_email_1_sex_1_course_1")

Answer 2

Just to make full answer.

From documentation: http://docs.mongodb.org/manual/reference/method/db.collection.dropIndex/ you should use db.collection.dropIndex() with string or document that:

Specifies the index to drop. You can specify the index either by the index name or by the index specification document.

So both:

db.people.dropIndex("personname_1_email_1_sex_1_course_1")
db.people.dropIndex({personname:1,email:1,sex:1,course:1})

works fine.