MongoDB Search and MongoDB Vector Search Indexes

Overview

In this guide, you can learn how to programmatically manage your MongoDB Search and MongoDB Vector Search indexes by using the Ruby driver.

The MongoDB Search feature enables you to perform full-text searches on collections hosted on MongoDB Atlas. To learn more about MongoDB Search, see the MongoDB Search Overview.

MongoDB Vector Search enables you to perform semantic searches on vector embeddings stored in MongoDB Atlas. To learn more about MongoDB Vector Search, see the MongoDB Vector Search Overview.

You can call the following methods to manage your MongoDB Search and MongoDB Vector Search indexes:

• search_indexes#create_one

• search_indexes#create_many

• search_indexes#update_one

• search_indexes#drop_one

The following sections provide code examples that demonstrate how to use each of the preceding commands.

Create a Search Index

To create a single MongoDB Search or MongoDB Vector Search index, use the search_indexes#create_one method. To create multiple indexes, use the search_indexes#create_many method. Both methods return immediately, while the indexes are asynchronously created in the background.

The following code example shows how to create a MongoDB Search index by providing an index definition and an optional name for the index:

# Creates indexes on all dynamically indexable fields with a default index name
collection.search_indexes.create_one(
  { mappings: { dynamic: true } } 
)
# Creates an index on the specified field with the specified index name
index_definition = {
  mappings: {
    dynamic: false,  
    fields: { 
      fullplot: { type: 'string' }
    }
  }
}
collection.search_indexes.create_one(index_definition, name: 'mySearchIndex')

You can use search_indexes#create_many to create multiple MongoDB Search or MongoDB Vector Search indexes by providing an array of index specifications. Each index specification should include the following components:

• definition parameter: Defines the index

• name parameter: Specifies the index name

• type parameter: Specifies the type of index ('search' or 'vectorSearch')

The following code example shows how to create both MongoDB Search and MongoDB Vector Search indexes in one call:

index_spec_1 = {
  name: 'searchIndex_plot',
  type: 'search',
  definition: {
    mappings: {
      dynamic: false,  
      fields: { 
        plot: { type: 'string' }
      }
    }
  }
}
index_spec_2 = {
  name: 'vsIndex_plot_embedding',
  type: 'vectorSearch',
  definition: {
    fields: [
      {
        type: "vector",
        path: "plot_embedding",
        numDimensions: 1536,
        similarity: "dotProduct"
      }
    ]
  }
}
collection.search_indexes.create_many([index_spec_1, index_spec_2])

For longer index definitions, it is helpful to define the index definitions outside of the method call. To learn more about the syntax of index definitions, see the Review MongoDB Search Index Syntax or the How to Index Fields for MongoDB Vector Search guides in the Atlas manual.

Update a Search Index

To update a MongoDB Search or MongoDB Vector Search index, use the search_indexes#update_one method.

To update an index, you must provide a new index definition. You must specify the index you want to update by using either the name or id of the index. The following code shows how to update a MongoDB Search index:

updated_definition = {
  mappings: {
    dynamic: false,  
    fields: { fullplot: { type: 'string' } }
    }
}
# Specifies the index to update by using the index name
collection.search_indexes.update_one(updated_definition, name: 'searchIndex_plot')
# Specifies the index to update by using the index id
collection.search_indexes.update_one(updated_definition, id: <index id>)

Delete a Search Index

To delete a MongoDB Search or MongoDB Vector Search index, use the search_indexes#drop_one method.

To delete an index, you must provide the id or name of the index. The following code shows how to delete a search index from a collection:

# Specifies the index to delete by using the index name
collection.search_indexes.drop_one(name: 'searchIndex_plot')
# Specifies the index to delete by using the index id
collection.search_indexes.drop_one(id: <index id>)

List Search Indexes

You can use the search_indexes object to list the entire index specification of each MongoDB Search and MongoDB Vector Search index on a collection:

puts collection.search_indexes.collect(&:to_json)

To list individual fields in the index specification for each index, iterate over the search_indexes object:

collection.search_indexes.each do |index_spec|
  p index_spec['id']
  p index_spec['name']
  p index_spec['status']
  p index_spec['queryable']
  p index_spec['latestDefinition']
end

Additional Information

To learn more about MongoDB Search, see the MongoDB Search documentation.

To learn more about MongoDB Vector Search, see the Ruby driver's Run a MongoDB Vector Search Query guide or the MongoDB Vector Search documentation.