Optimize Queries by Using Indexes

Overview

On this page, you can see copyable code examples that show how to manage different types of indexes by using the MongoDB Ruby Driver.

To use an example from this page, copy the code example into the sample application or your own application. Be sure to replace all placeholders in the code examples, such as <connection string>, with the relevant values for your MongoDB deployment.

require 'mongo'
# Replace the placeholders with your credentials
uri = "<connection string>"
# Sets the server_api field of the options object to Stable API version 1
options = { server_api: { version: "1" }}
# Creates a new client and connect to the server
client = Mongo::Client.new(uri, options)
database = client.use('<database name>')
collection = database[:<collection name>]
# Start example code here
    
# End example code here
client.close

Single Field Index

The following example creates an ascending index on the specified field:

collection.indexes.create_one({ <field name>: 1 })

To learn more about single field indexes, see the Single Field Indexes guide.

Compound Index

The following example creates a compound index on the two specified fields.

collection.indexes.create_one({ <field name 1>: -1, <field name 2>: 1 })

To learn more about compound indexes, see the Compound Indexes guide.

Multikey Index

The following example creates a multikey index on the specified array-valued field:

collection.indexes.create_one({ <field name>: 1 })

To learn more about multikey indexes, see the Multikey Indexes guide.

Geospatial Index

The following example creates a 2dsphere index on the specified field that contains GeoJSON objects:

collection.indexes.create_one({ <GeoJSON field name>: '2dsphere' })

To learn more about geospatial indexes, see the Geospatial Indexes guide.

Atlas Search Index Management

The following sections contain code examples that describe how to manage Atlas Search indexes.

To learn more about search indexes, see the Atlas Search Indexes guide.

index_definition = {
  mappings: {
    dynamic: false,  
    fields: { 
      <field name>: { type: '<field type>' }
    }
  }
}
collection.search_indexes.create_one(index_definition, name: '<index name>')

puts collection.search_indexes.collect(&:to_json)

updated_definition = {
  mappings: {
    dynamic: false,  
    fields: { <updated field name>: { type: '<updated field type>' } }
    }
}
collection.search_indexes.update_one(updated_definition, name: '<index name>')

collection.search_indexes.drop_one(name: '<index name>')

Text Index

The following example creates a text index on the specified string field:

collection.indexes.create_one({ <field name>: 'text' })

To learn more about text indexes, see the Text Indexes guide.

Create Many Indexes

The following example creates multiple indexes on the given array of index specifications:

collection.indexes.create_many([
  { key: { <field name 1>: 1 } },
  { key: { <field name 2>: -1 } },
])

Drop Index

The following example deletes an index with the specified name:

collection.indexes.drop_one( '<index name>' )

The following example shows how to delete all indexes in a collection:

collection.indexes.drop_all

List Indexes

The following example prints a list of all indexes in the specified collection:

puts collection.indexes.collect(&:to_json)

Index Options

The following is a full list of the available options you can add when creating indexes. These options mirror the options supported by the createIndex command. For more information, see the createIndex command in the MongoDB Server manual.

API Documentation

To learn more about the methods or objects used in this guide, see the following API documentation:

• indexes

• create_one

• drop_one

• drop_all