Which index is created by MongoDB for every collection?

When creating documents in a collection, MongoDB creates a unique index using the _id field. MongoDB refers to this as the Default _id Index. This default index cannot be dropped from the collection.

How many text indexes can a MongoDB collection have?

Text Index text indexes can include any field whose value is a string or an array of string elements. To perform text search queries, you must have a text index on your collection. A collection can only have one text search index, but that index can cover multiple fields.

Can we create multiple indexes in MongoDB?

MongoDB supports several different index types including text, geospatial, and hashed indexes.

What is MongoDB default index?

Default Index. In MongoDB indexing, all the collections have a default index on the _id field. If we don’t specify any value for the _id the MongoDB will create _id field with an object value. This index prevents clients from creating two documents with the same value _id field.

Which of the following are indexes supported by MongoDB?

MongoDB provides two geospatial indexes known as 2d indexes and 2d sphere indexes using these indexes we can query geospatial data. Here, the 2d indexes support queries that are used to find data that is stored in a two-dimensional plane.

What is the maximum size of a MongoDB document?

16 megabytes
The maximum BSON document size is 16 megabytes. The maximum document size helps ensure that a single document cannot use excessive amount of RAM or, during transmission, excessive amount of bandwidth. To store documents larger than the maximum size, MongoDB provides the GridFS API.

What is the maximum size of index key limit and number of indexes per collection?

Explanation. The total size of an index entry, which can include structural overhead depending on the BSON type, must be less than 1024 bytes. A single collection can have no more than 64 indexes.

How do I drop all indexes in MongoDB?

The index or indexes to drop.

1. To drop all but the _id index from the collection, specify “*” .
2. To drop a single index, specify either the index name, the index specification document (unless the index is a text index), or an array of the index name.

How do I see indexes in MongoDB?

View Existing Indexes To view a list of all indexes on a collection in MongoDB Compass, click on the target collection in the left-hand pane and select the Indexes tab. For details on the information displayed in this tab, refer to the Compass documentation.

How many types of indexes are there in MongoDB?

What is the maximum size of index key limit and number of indexes per collection Mcq?

A collection cannot have more than 64 indexes. The length of the index name cannot be longer than 125 characters.

How many collections can be created in MongoDB?

In general, we recommend limiting collections to 10,000 per replica set. When users begin exceeding 10,000 collections, they typically see decreases in performance. To avoid this anti-pattern, examine your database and remove unnecessary collections.

How do I create an index on a collection in MongoDB?

To create an index on a collection in MongoDB Compass, the collection must contain documents. In the left-hand MongoDB Compass navigation pane, click the database that contains your desired collection. From the database view, click the target collection name. From the Indexes tab, click the Create Index button to bring up the Create Index dialog.

What are the different types of index types supported by MongoDB?

MongoDB supports several different index types including text, geospatial, and hashed indexes. See index types for more information. Changed in version 4.2: MongoDB 4.2 wildcard indexes support workloads where users query against custom fields or a large variety of fields in a collection:

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.

How do I create a case-insensitive Index in MongoDB?

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. By specifying a collation strength of 1 or 2, you can create a case-insensitive index.