db.collection.dropIndexes()

Definition

  • db.collection.dropIndexes()

mongo Shell Method

This page documents the mongo shell method, and doesnot refer to the MongoDB Node.js driver (or any other driver)method. For corresponding MongoDB driver API, refer to your specificMongoDB driver documentation instead.

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.
  1. 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 atext index in which case, use theindex name to drop):
  1. db.collection.dropIndexes( { a: 1, b: 1 } )
  1. -

The index name:

  1. db.collection.dropIndexes( "a_1_b_1" )

Tip

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

  • Drop specified indexes from a collection. (Available starting inMongoDB 4.2). To specify multiple indexes to drop, pass the methodan array of index names:
  1. db.collection.dropIndexes( [ "a_1_b_1", "a_1", "a_1__id_-1" ] )

If the array of indexnames includes a non-existent index, the method errors withoutdropping any of the specified indexes.

Tip

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

The db.collection.dropIndexes() method takes the followingoptional parameter:

ParameterTypeDescriptionindexesstring or document or array of stringsOptional. 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, theindex specification document (unless the index is atext index), or an array of theindex name. To drop a text index,specify the index name or an array of the index name insteadof the index specification document.

To drop multiple indexes (Available starting in MongoDB4.2), specify an array of the index names.

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

Behavior

Starting in MongoDB 4.2, the dropIndexes() operation only killsqueries that are using the index being dropped. This may includequeries considering the index as part ofquery planning.

Prior to MongoDB 4.2, dropping an index on acollection would kill all open queries on the collection.

Resource Locking

Changed in version 4.2.

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

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

Index Names

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

_id Index

You cannot drop the default index on the _id field.

text Indexes

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