db.collection.dropIndex()¶

db.collection.dropIndex(index)¶

Drops or removes the specified index from a collection. The db.collection.dropIndex() method provides a wrapper around the dropIndexes command.

Note

You cannot drop the default index on the _id field.

The db.collection.dropIndex() method takes the following parameter:

Parameters:	index – Specifies the index to drop. You can specify the index either by the index name or by the index specification document. [1] See Index Specification Documents for information on index specification documents. To view all indexes on a collection, use the `db.collection.getIndexes()` method.

The following example uses the db.collection.dropIndex() method on the collection pets that has the following indexes:

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> db.pets.getIndexes()
[
   {  "v" : 1,
      "key" : { "_id" : 1 },
      "ns" : "test.pets",
      "name" : "_id_"
   },
   {
      "v" : 1,
      "key" : { "cat" : -1 },
      "ns" : "test.pets",
      "name" : "catIdx"
   },
   {
      "v" : 1,
      "key" : { "cat" : 1, "dog" : -1 },
      "ns" : "test.pets",
      "name" : "cat_1_dog_-1"
   }
]

Consider the index on the field cat. The index has the user-specified name of catIdx [2]. To drop the index catIdx, you can use either the index name:

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db.pets.dropIndex( "catIdx" )

or the index specification document { "cat" : 1 }:

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db.pets.dropIndex( { "cat" : 1 } )

[1]	When using a `mongo` shell version earlier than 2.2.2, if you specified a name during the index creation, you must use the name to drop the index.

[2]	During index creation, if the user does not specify an index name, the system generates the name by concatenating the index key field and value with an underscore, e.g. `cat_1`.

← db.collection.drop() db.collection.dropIndexes() →