createIndexes¶

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Definition
Considerations
Behavior
Example
Output

2.6 新版功能.

Definition¶

createIndexes¶

Builds one or more indexes on a collection.

在 3.2 版更改: Starting in MongoDB 3.2, MongoDB disallows the creation of version 0 indexes. To upgrade existing version 0 indexes, see Version 0 Indexes.

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:

在 3.0 版更改: 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 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.
`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: equality expressions (i.e. `field: value` or using the `$eq` operator), `$exists: true` expression, `$gt`, `$gte`, `$lt`, `$lte` expressions, `$type` expressions, `$and` operator at the top-level only You can specify a `partialFilterExpression` option for all MongoDB index types. 3.2 新版功能.
`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 稀疏索引 for more information. 在 3.2 版更改: 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. 在 2.6 版更改: 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 通过设置TTL使集合中的数据过期 for more information on this functionality. This applies only to TTL indexes.
`storageEngine`	document	Optional. Allows users to specify configuration to the storage engine on a per-index basis when creating an index. The value of the `storageEngine` option should take the following form: { <storage-engine-name>: <options> } Storage engine configuration specified when creating indexes are validated and logged to the oplog during replication to support replica sets with members that use different storage engines. 3.0 新版功能.
`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 通过权重控制搜索结果 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 文本搜索语言 for the available languages and 指定文本索引的语言 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 使用任意键为文档指定语言 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`. 2.6 新版功能.
`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`. 2.6 新版功能.
`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. 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. 3.4 新版功能.

Considerations¶

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

Behavior¶

Concurrency¶

Non-background indexing operations block all other operations on a database.

Multiple Index Builds¶

在 3.0.0 版更改.

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.

Index Options¶

With the exception of the collation option, 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 these index options, drop the existing index with db.collection.dropIndex() before running the new createIndexes with the new options.

Collation Option¶

Unlike other index options, you can create multiple indexes on the same key(s) with different collations. To create indexes with the same key pattern but different collations, you must supply unique index names.

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 that collation.
If you do specify a collation when creating the index, MongoDB creates the index with the specified collation.

Tip

By specifying a collation strength of 1 or 2, you can create a case-insensitive index. Index with a collation strength of 1 is both diacritic- and case-insensitive.

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.

← filemd5 listIndexes →