createIndexes

Definition

createIndexes

Builds one or more indexes on a collection.

The createIndexes command takes the following form:

db.runCommand(
  {
    createIndexes: <collection>,
    indexes: [
        {
            key: {
                <key-value_pair>,
                <key-value_pair>,
                ...
            },
            name: <index_name>,
            <option1>,
            <option2>,
            ...
        },
        { ... },
        { ... }
    ],
    writeConcern: { <write concern> }
  }
)

The createIndexes command takes the following fields:

Field Type Description
createIndexes string The collection for which to create indexes.
indexes array Specifies the indexes to create. Each document in the array specifies a separate index.
writeConcern document

Optional. A document expressing the write concern. Omit to use the default write concern.

New in version 3.4.

Each document in the indexes array can take the following fields:

Changed in version 3.0: The dropDups option is no longer available.

Field Type Description
key document Specifies the index’s fields. For each field, specify a key-value pair in which the key is the name of the field to index and the value is either the index direction or index type. If specifying direction, specify 1 for ascending or -1 for descending.
name string A name that uniquely identifies the index.
background boolean Optional. Builds the index in the background so the operation does not block other database activities. Specify true to build in the background. The default value is false.
unique boolean

Optional. Creates a unique index so that the collection will not accept insertion or update of documents where the index key value matches an existing value in the index.

Specify true to create a unique index. The default value is false.

The option is unavailable for hashed indexes.

partialFilterExpression document

Optional. If specified, the index only references documents that match the filter expression. See Partial Indexes for more information.

A filter expression can include:

You can specify a partialFilterExpression option for all MongoDB index types.

New in version 3.2.

sparse boolean

Optional. If true, the index only references documents with the specified field. These indexes use less space but behave differently in some situations (particularly sorts). The default value is false. See Sparse Indexes for more information.

Changed in version 3.2: Starting in MongoDB 3.2, MongoDB provides the option to create partial indexes. Partial indexes offer a superset of the functionality of sparse indexes. If you are using MongoDB 3.2 or later, partial indexes should be preferred over sparse indexes.

Changed in version 2.6: 2dsphere indexes are sparse by default and ignore this option. For a compound index that includes 2dsphere index key(s) along with keys of other types, only the 2dsphere index fields determine whether the index references a document.

2d, geoHaystack, and text indexes behave similarly to the 2dsphere indexes.

expireAfterSeconds integer Optional. Specifies a value, in seconds, as a TTL to control how long MongoDB retains documents in this collection. See Expire Data from Collections by Setting TTL for more information on this functionality. This applies only to TTL indexes.
storageEngine document

Optional. Allows users to configure the storage engine on a per-index basis when creating an index.

The storageEngine option should take the following form:

storageEngine: { <storage-engine-name>: <options> }

Storage engine configuration options specified when creating indexes are validated and logged to the oplog during replication to support replica sets with members that use different storage engines.

New in version 3.0.

weights document Optional. For text indexes, a document that contains field and weight pairs. The weight is an integer ranging from 1 to 99,999 and denotes the significance of the field relative to the other indexed fields in terms of the score. You can specify weights for some or all the indexed fields. See Control Search Results with Weights to adjust the scores. The default value is 1.
default_language string Optional. For text indexes, the language that determines the list of stop words and the rules for the stemmer and tokenizer. See Text Search Languages for the available languages and Specify a Language for Text Index for more information and examples. The default value is english.
language_override string Optional. For text indexes, the name of the field, in the collection’s documents, that contains the override language for the document. The default value is language. See Use any Field to Specify the Language for a Document for an example.
textIndexVersion integer

Optional. The text index version number. Users can use this option to override the default version number.

For available versions, see Versions.

New in version 2.6.

2dsphereIndexVersion integer

Optional. The 2dsphere index version number. Users can use this option to override the default version number.

For the available versions, see Versions.

New in version 2.6.

bits integer

Optional. For 2d indexes, the number of precision of the stored geohash value of the location data.

The bits value ranges from 1 to 32 inclusive. The default value is 26.

min number Optional. For 2d indexes, the lower inclusive boundary for the longitude and latitude values. The default value is -180.0.
max number Optional. For 2d indexes, the upper inclusive boundary for the longitude and latitude values. The default value is 180.0.
bucketSize number

For geoHaystack indexes, specify the number of units within which to group the location values; i.e. group in the same bucket those location values that are within the specified number of units to each other.

The value must be greater than 0.

collation document

Optional. Specifies the collation for the index.

Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.

If you have specified a collation at the collection level, then:

  • If you do not specify a collation when creating the index, MongoDB creates the index with the collection’s default collation.
  • If you do specify a collation when creating the index, MongoDB creates the index with the specified collation.

The collation option has the following syntax:

collation: {
   locale: <string>,
   caseLevel: <boolean>,
   caseFirst: <string>,
   strength: <int>,
   numericOrdering: <boolean>,
   alternate: <string>,
   maxVariable: <string>,
   backwards: <boolean>
}

When specifying collation, the locale field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document.

New in version 3.4.

The mongo shell provides the methods db.collection.createIndex() and db.collection.createIndexes() as wrappers for the createIndexes command.

Considerations

Changed in version 3.2: MongoDB disallows the creation of version 0 indexes. To upgrade existing version 0 indexes, see Version 0 Indexes.

Index Names

An index name, including the namespace, cannot be longer than the Index Name Length limit.

Replica Sets and Sharded Clusters

To minimize the impact of building an index on replica sets and sharded clusters, use a rolling index build procedure as described on Build Indexes on Replica Sets.

Collation and Index Types

The following indexes only support simple binary comparison and do not support collation:

Tip

To create a text, a 2d, or a geoHaystack index on a collection that has a non-simple collation, you must explicitly specify {collation: {locale: "simple"} } when creating the index.

Behavior

Concurrency

Foreground indexing operations on a populated collection block all other operations on a database.

Multiple Index Builds

Changed in version 3.0.0.

If you specify multiple indexes to the createIndexes command, the operation only scans the collection once, and if at least one index is to be built in the foreground, the operation will build all the specified indexes in the foreground.

Memory Usage Limit

Changed in version 3.4: You can build one or more indexes on a collection with the database command createIndexes. The default limit on memory usage for a createIndexes operation is 500 megabytes. You can override this limit by setting the