OPTIONS

createIndexes

New in version 2.6.

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>,
            ...
        },
        { ... },
        { ... }
    ]
  }
)

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.

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

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.
ns string Optional. The namespace (i.e. <database>.<collection>) of the collection for which to create the index. If you omit ns, MongoDB generates the namespace.
background Boolean Optional. Builds the index in the background so that building an index 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 of documents where the index key or keys match 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.

dropDups Boolean

Optional. Creates a unique index on a field that may have duplicates. MongoDB indexes only the first occurrence of a key and removes all documents from the collection that contain subsequent occurrences of that key. Specify true to create unique index. The default value is false.

The option is unavailable for hashed indexes.

Deprecated since version 2.6.

Warning

dropDups will delete data from your collection when building the index.

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 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.
v index version Optional. The index version number. The default index version depends on the version of mongod running when creating the index. Before version 2.0, the this value was 0; versions 2.0 and later use version 1, which provides a smaller and faster index format. Specify a different index version only in unusual situations.
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. For text indexes, the text index version number. Version can be either 1 or 2.

In MongoDB 2.6, the default version is 2. MongoDB 2.4 can only support version 1.

New in version 2.6.

2dsphereIndexVersion integer

Optional. For 2dsphere indexes, the 2dsphere index version number. Version can be either 1 or 2.

In MongoDB 2.6, the default version is 2. MongoDB 2.4 can only support version 1.

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.

Considerations

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

Behavior

Non-background indexing operations block all other operations on a database. If you specify multiple indexes to createIndexes, MongoDB builds the indexes serially.

If you create an index with one set of options and then issue createIndexes with the same index fields but different options, MongoDB will not change the options nor rebuild the index. To change index options, drop the existing index with db.collection.dropIndex() before running the new createIndexes with the new options.

Example

The following command builds two indexes on the inventory collection of the products database:

db.getSiblingDB("products").runCommand(
  {
    createIndexes: "inventory",
    indexes: [
        {
            key: {
                item: 1,
                manufacturer: 1,
                model: 1
            },
            name: "item_manufacturer_model",
            unique: true
        },
        {
            key: {
                item: 1,
                supplier: 1,
                model: 1
            },
            name: "item_supplier_model",
            unique: true
        }
    ]
  }
)

When the indexes successfully finish building, MongoDB returns a results document that includes a status of "ok" : 1.

Output

The createIndexes command returns a document that indicates the success of the operation. The document contains some but not all of the following fields, depending on outcome:

createIndexes.createdCollectionAutomatically

If true, then the collection didn’t exist and was created in the process of creating the index.

createIndexes.numIndexesBefore

The number of indexes at the start of the command.

createIndexes.numIndexesAfter

The number of indexes at the end of the command.

createIndexes.ok

A value of 1 indicates the indexes are in place. A value of 0 indicates an error.

createIndexes.note

This note is returned if an existing index or indexes already exist. This indicates that the index was not created or changed.

createIndexes.errmsg

Returns information about any errors.

createIndexes.code

The error code representing the type of error.

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