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db.collection.dropIndexes()

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Definition

db.collection.dropIndexes()

Drops the specified index or indexes (except the index on the _id field) from a collection.

You can use the method to:

  • Drop all but the _id index from a collection.

    db.collection.dropIndexes()
    
  • Drop a specified index from a collection. To specify the index, you can pass the method either:

    • The index specification document (unless the index is a text index in which case, use the index name to drop):

      db.collection.dropIndexes( { a: 1, b: 1 } )
      
    • The index name:

      db.collection.dropIndexes( "a_1_b_1" )
      

      Tip

      To get the names of the indexes, use the db.collection.getIndexes() method.

  • Drop specified indexes from a collection. (Available starting in MongoDB 4.2). To specify multiple indexes to drop, pass the method an array of index names:

    db.collection.dropIndexes( [ "a_1_b_1", "a_1", "a_1__id_-1" ] )
    

    If the array of index names includes a non-existent index, the method errors without dropping any of the specified indexes.

    Tip

    To get the names of the indexes, use the db.collection.getIndexes() method.

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

Parameter Type Description
indexes string or document or array of strings

Optional. Specifies the index or indexes to drop.

To drop all but the _id index from the collection, omit the parameter.

To drop a single index, specify either the index name, the index specification document (unless the index is a text index), or an array of the index name. To drop a text index, specify the index name or an array of the index name instead of the index specification document.

To drop multiple indexes (Available starting in MongoDB 4.2), specify an array of the index names.

The db.collection.getIndexes() is a wrapper around the dropIndexes command.

Behavior

Resource Locking

Changed in version 4.2.

db.collection.dropIndexes() obtains an exclusive lock on the specified collection for the duration of the operation. All subsequent operations on the collection must wait until db.collection.dropIndexes() releases the lock.

Prior to MongoDB 4.2, db.collection.dropIndexes() obtained an exclusive lock on the parent database, blocking all operations on the database and all its collections until the operation completed.

Index Names

If the method is passed an array of index names that includes a non-existent index, the method errors without dropping any of the specified indexes.

_id Index

You cannot drop the default index on the _id field.

text Indexes

To drop a text index, specify the index name instead of the index specification document.