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createIndexes¶
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New in version 2.6.
Definition¶
-
createIndexes
¶ Builds one or more indexes on a collection. The
createIndexes
command takes the following form: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 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 isfalse
.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 isfalse
.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 isfalse
.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 isfalse
. 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 the2dsphere
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 either1
or2
.In MongoDB 2.6, the default version is
2
. MongoDB 2.4 can only support version1
.New in version 2.6.
2dsphereIndexVersion
integer Optional. For 2dsphere indexes, the
2dsphere
index version number. Version can be either1
or2
.In MongoDB 2.6, the default version is
2
. MongoDB 2.4 can only support version1
.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 is26
.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.
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 omitns
, MongoDB generates the namespace.
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:
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 of0
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.