Can you create an index on an array field in MongoDB?

MongoDB automatically creates a multikey index if any indexed field is an array; you do not need to explicitly specify the multikey type.

How indexes are created in MongoDB?

Indexes support the efficient execution of queries in MongoDB. Without indexes, MongoDB must perform a collection scan, i.e. scan every document in a collection, to select those documents that match the query statement.

Can we create index in MongoDB?

Indexes can be created by using the createIndex method. Indexes can be created on just one field or multiple field values. Indexes can be found by using the getIndexes method. Indexes can be removed by using the dropIndex for single indexes or dropIndexes for dropping all indexes.

How do you create a text index MongoDB?

In MongoDB, we can create text indexes using db. collectionName. createIndex() method. So, to index a field that contains either string or an array of string elements, pass a document in the createIndex() method that contains the field and the string literal(i.e., “text”).

Does MongoDB support geospatial indexes?

MongoDB’s geospatial indexing allows you to efficiently execute spatial queries on a collection that contains geospatial shapes and points. This tutorial will briefly introduce the concepts of geospatial indexes, and then demonstrate their use with $geoWithin , $geoIntersects , and $nearSphere .

How do I create a compound index in MongoDB compass?

To create an index on a collection via Compass, the collection must contain documents.

1. Click the Create Index button. ¶ From the Indexes tab, click the Create Index button to bring up the Create Index dialog.
2. Optional. Enter the index name. ¶
3. Add fields to index. ¶ Specify an index key.

How does text index work in MongoDB?

For a text index, the weight of an indexed field denotes the significance of the field relative to the other indexed fields in terms of the text search score. For each indexed field in the document, MongoDB multiplies the number of matches by the weight and sums the results.

How do I add text to index?

Create the index

1. Click where you want to add the index.
2. On the References tab, in the Index group, click Insert Index.
3. In the Index dialog box, you can choose the format for text entries, page numbers, tabs, and leader characters.
4. You can change the overall look of the index by choosing from the Formats dropdown menu.

What is geospatial index in MongoDB?

Overview. A 2dsphere index supports queries that calculate geometries on an earth-like sphere. 2dsphere index supports all MongoDB geospatial queries: queries for inclusion, intersection and proximity. For more information on geospatial queries, see Geospatial Queries.

Which MongoDB command will show the available indexes?

You can find all the available indexes in a MongoDB collection by using the getIndexes method. This will return all the indexes in a specific collection. Result: The output contains the default _id index and the user-created index student name index.

What are the different types of indexing in MongoDB?

Index Types ¶. 1 Single Field ¶. In addition to the MongoDB-defined _id index, MongoDB supports the creation of user-defined ascending/descending indexes on a single 2 Compound Index ¶. 3 Multikey Index ¶. 4 Geospatial Index ¶. 5 Text Indexes ¶.

What is unique index and missing field in MongoDB?

Unique Index and Missing Field ¶ If a document does not have a value for the indexed field in a unique index, the index will store a null value for this document. Because of the unique constraint, MongoDB will only permit one document that lacks the indexed field.

How do I reference a document in another document in MongoDB?

MongoDB applications use one of two methods for relating documents: Manual references where you save the _id field of one document in another document as a reference. DBRefs are references from one document to another using the value of the first document’s _id field, collection name, and, optionally, its database name.

How does MongoDB limit the number of documents it can inspect?

If an appropriate index exists for a query, MongoDB can use the index to limit the number of documents it must inspect. Indexes are special data structures [ 1] that store a small portion of the collection’s data set in an easy to traverse form.