ElasticKnnSearch

class langchain_community.vectorstores.elastic_vector_search.ElasticKnnSearch(index_name: str, embedding: Embeddings, es_connection: 'Elasticsearch' | None = None, es_cloud_id: str | None = None, es_user: str | None = None, es_password: str | None = None, vector_query_field: str | None = 'vector', query_field: str | None = 'text')

Deprecated since version 0.0.1: Use Use ElasticsearchStore class in langchain-elasticsearch package instead.

[DEPRECATED] Elasticsearch with k-nearest neighbor search (k-NN) vector store.

Recommended to use ElasticsearchStore instead, which supports metadata filtering, customising the query retriever and much more!

You can read more on ElasticsearchStore: https://python.langchain.com/docs/integrations/vectorstores/elasticsearch

It creates an Elasticsearch index of text data that can be searched using k-NN search. The text data is transformed into vector embeddings using a provided embedding model, and these embeddings are stored in the Elasticsearch index.

Parameters:

• index_name (str) –

• embedding (Embeddings) –

• es_connection (Optional['Elasticsearch']) –

• es_cloud_id (Optional[str]) –

• es_user (Optional[str]) –

• es_password (Optional[str]) –

• vector_query_field (Optional[str]) –

• query_field (Optional[str]) –

index_name

The name of the Elasticsearch index.

Type:

str

embedding

The embedding model to use for transforming text data into vector embeddings.

Type:

Embeddings

es_connection

An existing Elasticsearch connection.

Type:

Elasticsearch, optional

es_cloud_id

The Cloud ID of your Elasticsearch Service deployment.

Type:

str, optional

es_user

The username for your Elasticsearch Service deployment.

Type:

str, optional

es_password

The password for your Elasticsearch Service deployment.

Type:

str, optional

vector_query_field

The name of the field in the Elasticsearch index that contains the vector embeddings.

Type:

str, optional

query_field

The name of the field in the Elasticsearch index that contains the original text data.

Type:

str, optional

Usage:

>>> from embeddings import Embeddings
>>> embedding = Embeddings.load('glove')
>>> es_search = ElasticKnnSearch('my_index', embedding)
>>> es_search.add_texts(['Hello world!', 'Another text'])
>>> results = es_search.knn_search('Hello')
[(Document(page_content='Hello world!', metadata={}), 0.9)]

Attributes

embeddings

Access the query embedding object if available.

Methods

__init__(index_name, embedding[, ...])
aadd_documents(documents, **kwargs)	Async run more documents through the embeddings and add to the vectorstore.
aadd_texts(texts[, metadatas])	Async run more texts through the embeddings and add to the vectorstore.
add_documents(documents, **kwargs)	Add or update documents in the vectorstore.
add_texts(texts[, metadatas, model_id, ...])	Add a list of texts to the Elasticsearch index.
adelete([ids])	Async delete by vector ID or other criteria.
afrom_documents(documents, embedding, **kwargs)	Async return VectorStore initialized from documents and embeddings.
afrom_texts(texts, embedding[, metadatas])	Async return VectorStore initialized from texts and embeddings.
aget_by_ids(ids, /)	Async get documents by their IDs.
amax_marginal_relevance_search(query[, k, ...])	Async return docs selected using the maximal marginal relevance.
amax_marginal_relevance_search_by_vector(...)	Async return docs selected using the maximal marginal relevance.
as_retriever(**kwargs)	Return VectorStoreRetriever initialized from this VectorStore.
asearch(query, search_type, **kwargs)	Async return docs most similar to query using a specified search type.
asimilarity_search(query[, k])	Async return docs most similar to query.
asimilarity_search_by_vector(embedding[, k])	Async return docs most similar to embedding vector.
asimilarity_search_with_relevance_scores(query)	Async return docs and relevance scores in the range [0, 1].
asimilarity_search_with_score(*args, **kwargs)	Async run similarity search with distance.
create_knn_index(mapping)	Create a new k-NN index in Elasticsearch.
delete([ids])	Delete by vector ID or other criteria.
from_documents(documents, embedding, **kwargs)	Return VectorStore initialized from documents and embeddings.
from_texts(texts, embedding[, metadatas])	Create a new ElasticKnnSearch instance and add a list of texts to the
get_by_ids(ids, /)	Get documents by their IDs.
knn_hybrid_search([query, k, query_vector, ...])	Perform a hybrid k-NN and text search on the Elasticsearch index.
knn_search([query, k, query_vector, ...])	Perform a k-NN search on the Elasticsearch index.
max_marginal_relevance_search(query[, k, ...])	Return docs selected using the maximal marginal relevance.
max_marginal_relevance_search_by_vector(...)	Return docs selected using the maximal marginal relevance.
search(query, search_type, **kwargs)	Return docs most similar to query using a specified search type.
similarity_search(query[, k, filter])	Pass through to knn_search
similarity_search_by_vector(embedding[, k])	Return docs most similar to embedding vector.
similarity_search_with_relevance_scores(query)	Return docs and relevance scores in the range [0, 1].
similarity_search_with_score(query[, k])	Pass through to knn_search including score

__init__(index_name: str, embedding: Embeddings, es_connection: 'Elasticsearch' | None = None, es_cloud_id: str | None = None, es_user: str | None = None, es_password: str | None = None, vector_query_field: str | None = 'vector', query_field: str | None = 'text')

Parameters:

• index_name (str) –

• embedding (Embeddings) –

• es_connection (Optional['Elasticsearch']) –

• es_cloud_id (Optional[str]) –

• es_user (Optional[str]) –

• es_password (Optional[str]) –

• vector_query_field (Optional[str]) –

• query_field (Optional[str]) –

async aadd_documents(documents: List[Document], **kwargs: Any) → List[str]

Async run more documents through the embeddings and add to the vectorstore.

Parameters:

• documents (List[Document]) – Documents to add to the vectorstore.

• kwargs (Any) – Additional keyword arguments.

Returns:

List of IDs of the added texts.

Raises:

ValueError – If the number of IDs does not match the number of documents.

Return type:

List[str]

async aadd_texts(texts: Iterable[str], metadatas: List[dict] | None = None, **kwargs: Any) → List[str]

Async run more texts through the embeddings and add to the vectorstore.

Parameters:

• texts (Iterable[str]) – Iterable of strings to add to the vectorstore.

• metadatas (List[dict] | None) – Optional list of metadatas associated with the texts. Default is None.

• **kwargs (Any) – vectorstore specific parameters.

Returns:

List of ids from adding the texts into the vectorstore.

Raises:

• ValueError – If the number of metadatas does not match the number of texts.

• ValueError – If the number of ids does not match the number of texts.

Return type:

List[str]

add_documents(documents: List[Document], **kwargs: Any) → List[str]

Add or update documents in the vectorstore.

Parameters:

• documents (List[Document]) – Documents to add to the vectorstore.

• kwargs (Any) – Additional keyword arguments. if kwargs contains ids and documents contain ids, the ids in the kwargs will receive precedence.

Returns:

List of IDs of the added texts.

Raises:

ValueError – If the number of ids does not match the number of documents.

Return type:

List[str]

add_texts(texts: Iterable[str], metadatas: List[Dict[Any, Any]] | None = None, model_id: str | None = None, refresh_indices: bool = False, **kwargs: Any) → List[str]

Add a list of texts to the Elasticsearch index.

Parameters:

• texts (Iterable[str]) – The texts to add to the index.

• metadatas (List[Dict[Any, Any]], optional) – A list of metadata dictionaries to associate with the texts.

• model_id (str, optional) – The ID of the model to use for transforming the texts into vectors.

• refresh_indices (bool, optional) – Whether to refresh the Elasticsearch indices after adding the texts.

• **kwargs – Arbitrary keyword arguments.

Returns:

A list of IDs for the added texts.

Return type:

List[str]

async adelete(ids: List[str] | None = None, **kwargs: Any) → bool | None

Async delete by vector ID or other criteria.

Parameters:

• ids (List[str] | None) – List of ids to delete. If None, delete all. Default is None.

• **kwargs (Any) – Other keyword arguments that subclasses might use.

Returns:

True if deletion is successful, False otherwise, None if not implemented.

Return type:

Optional[bool]

async classmethod afrom_documents(documents: List[Document], embedding: Embeddings, **kwargs: Any) → VST

Async return VectorStore initialized from documents and embeddings.

Parameters:

• documents (List[Document]) – List of Documents to add to the vectorstore.

• embedding (Embeddings) – Embedding function to use.

• kwargs (Any) – Additional keyword arguments.

Returns:

VectorStore initialized from documents and embeddings.

Return type:

VectorStore

async classmethod afrom_texts(texts: List[str], embedding: Embeddings, metadatas: List[dict] | None = None, **kwargs: Any) → VST

Async return VectorStore initialized from texts and embeddings.

Parameters:

• texts (List[str]) – Texts to add to the vectorstore.

• embedding (Embeddings) – Embedding function to use.

• metadatas (List[dict] | None) – Optional list of metadatas associated with the texts. Default is None.

• kwargs (Any) – Additional keyword arguments.

Returns:

VectorStore initialized from texts and embeddings.

Return type:

VectorStore

async aget_by_ids(ids: Sequence[str], /) → List[Document]

Async get documents by their IDs.

The returned documents are expected to have the ID field set to the ID of the document in the vector store.

Fewer documents may be returned than requested if some IDs are not found or if there are duplicated IDs.

Users should not assume that the order of the returned documents matches the order of the input IDs. Instead, users should rely on the ID field of the returned documents.

This method should NOT raise exceptions if no documents are found for some IDs.

Parameters:

ids (Sequence[str]) – List of ids to retrieve.

Returns:

List of Documents.

Return type:

List[Document]

New in version 0.2.11.

async amax_marginal_relevance_search(query: str, k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, **kwargs: Any) → List[Document]

Async return docs selected using the maximal marginal relevance.

Maximal marginal relevance optimizes for similarity to query AND diversity among selected documents.

Parameters:

• query (str) – Text to look up documents similar to.

• k (int) – Number of Documents to return. Defaults to 4.

• fetch_k (int) – Number of Documents to fetch to pass to MMR algorithm. Default is 20.

• lambda_mult (float) – Number between 0 and 1 that determines the degree of diversity among the results with 0 corresponding to maximum diversity and 1 to minimum diversity. Defaults to 0.5.

• kwargs (Any) –

Returns:

List of Documents selected by maximal marginal relevance.

Return type:

List[Document]

async amax_marginal_relevance_search_by_vector(embedding: List[float], k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, **kwargs: Any) → List[Document]

Async return docs selected using the maximal marginal relevance.

Maximal marginal relevance optimizes for similarity to query AND diversity among selected documents.

Parameters:

• embedding (List[float]) – Embedding to look up documents similar to.

• k (int) – Number of Documents to return. Defaults to 4.

• fetch_k (int) – Number of Documents to fetch to pass to MMR algorithm. Default is 20.

• lambda_mult (float) – Number between 0 and 1 that determines the degree of diversity among the results with 0 corresponding to maximum diversity and 1 to minimum diversity. Defaults to 0.5.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents selected by maximal marginal relevance.

Return type:

List[Document]

as_retriever(**kwargs: Any) → VectorStoreRetriever

Return VectorStoreRetriever initialized from this VectorStore.

Parameters:

**kwargs (Any) –

Keyword arguments to pass to the search function. Can include: search_type (Optional[str]): Defines the type of search that

the Retriever should perform. Can be “similarity” (default), “mmr”, or “similarity_score_threshold”.

search_kwargs (Optional[Dict]): Keyword arguments to pass to the

search function. Can include things like:

k: Amount of documents to return (Default: 4) score_threshold: Minimum relevance threshold

for similarity_score_threshold

fetch_k: Amount of documents to pass to MMR algorithm

(Default: 20)

lambda_mult: Diversity of results returned by MMR;

1 for minimum diversity and 0 for maximum. (Default: 0.5)

filter: Filter by document metadata

Returns:

Retriever class for VectorStore.

Return type:

VectorStoreRetriever

Examples:

# Retrieve more documents with higher diversity
# Useful if your dataset has many similar documents
docsearch.as_retriever(
    search_type="mmr",
    search_kwargs={'k': 6, 'lambda_mult': 0.25}
)

# Fetch more documents for the MMR algorithm to consider
# But only return the top 5
docsearch.as_retriever(
    search_type="mmr",
    search_kwargs={'k': 5, 'fetch_k': 50}
)

# Only retrieve documents that have a relevance score
# Above a certain threshold
docsearch.as_retriever(
    search_type="similarity_score_threshold",
    search_kwargs={'score_threshold': 0.8}
)

# Only get the single most similar document from the dataset
docsearch.as_retriever(search_kwargs={'k': 1})

# Use a filter to only retrieve documents from a specific paper
docsearch.as_retriever(
    search_kwargs={'filter': {'paper_title':'GPT-4 Technical Report'}}
)

async asearch(query: str, search_type: str, **kwargs: Any) → List[Document]

Async return docs most similar to query using a specified search type.

Parameters:

• query (str) – Input text.

• search_type (str) – Type of search to perform. Can be “similarity”, “mmr”, or “similarity_score_threshold”.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents most similar to the query.

Raises:

ValueError – If search_type is not one of “similarity”, “mmr”, or “similarity_score_threshold”.

Return type:

List[Document]

async asimilarity_search(query: str, k: int = 4, **kwargs: Any) → List[Document]

Async return docs most similar to query.

Parameters:

• query (str) – Input text.

• k (int) – Number of Documents to return. Defaults to 4.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents most similar to the query.

Return type:

List[Document]

async asimilarity_search_by_vector(embedding: List[float], k: int = 4, **kwargs: Any) → List[Document]

Async return docs most similar to embedding vector.

Parameters:

• embedding (List[float]) – Embedding to look up documents similar to.

• k (int) – Number of Documents to return. Defaults to 4.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents most similar to the query vector.

Return type:

List[Document]

async asimilarity_search_with_relevance_scores(query: str, k: int = 4, **kwargs: Any) → List[Tuple[Document, float]]

Async return docs and relevance scores in the range [0, 1].

0 is dissimilar, 1 is most similar.

Parameters:

• query (str) – Input text.

• k (int) – Number of Documents to return. Defaults to 4.

• **kwargs (Any) –

  kwargs to be passed to similarity search. Should include: score_threshold: Optional, a floating point value between 0 to 1 to

  filter the resulting set of retrieved docs

Returns:

List of Tuples of (doc, similarity_score)

Return type:

List[Tuple[Document, float]]

async asimilarity_search_with_score(*args: Any, **kwargs: Any) → List[Tuple[Document, float]]

Async run similarity search with distance.

Parameters:

• *args (Any) – Arguments to pass to the search method.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Tuples of (doc, similarity_score).

Return type:

List[Tuple[Document, float]]

create_knn_index(mapping: Dict) → None

Create a new k-NN index in Elasticsearch.

Parameters:

mapping (Dict) – The mapping to use for the new index.

Returns:

None

Return type:

None

delete(ids: List[str] | None = None, **kwargs: Any) → bool | None

Delete by vector ID or other criteria.

Parameters:

• ids (List[str] | None) – List of ids to delete. If None, delete all. Default is None.

• **kwargs (Any) – Other keyword arguments that subclasses might use.

Returns:

True if deletion is successful, False otherwise, None if not implemented.

Return type:

Optional[bool]

classmethod from_documents(documents: List[Document], embedding: Embeddings, **kwargs: Any) → VST

Return VectorStore initialized from documents and embeddings.

Parameters:

• documents (List[Document]) – List of Documents to add to the vectorstore.

• embedding (Embeddings) – Embedding function to use.

• kwargs (Any) – Additional keyword arguments.

Returns:

VectorStore initialized from documents and embeddings.

Return type:

VectorStore

classmethod from_texts(texts: List[str], embedding: Embeddings, metadatas: List[Dict[Any, Any]] | None = None, **kwargs: Any) → ElasticKnnSearch

Create a new ElasticKnnSearch instance and add a list of texts to the

Elasticsearch index.

Parameters:

• texts (List[str]) – The texts to add to the index.

• embedding (Embeddings) – The embedding model to use for transforming the texts into vectors.

• metadatas (List[Dict[Any, Any]], optional) – A list of metadata dictionaries to associate with the texts.

• **kwargs – Arbitrary keyword arguments.

Returns:

A new ElasticKnnSearch instance.

Return type:

ElasticKnnSearch

get_by_ids(ids: Sequence[str], /) → List[Document]

Get documents by their IDs.

The returned documents are expected to have the ID field set to the ID of the document in the vector store.

Fewer documents may be returned than requested if some IDs are not found or if there are duplicated IDs.

Users should not assume that the order of the returned documents matches the order of the input IDs. Instead, users should rely on the ID field of the returned documents.

This method should NOT raise exceptions if no documents are found for some IDs.

Parameters:

ids (Sequence[str]) – List of ids to retrieve.

Returns:

List of Documents.

Return type:

List[Document]

New in version 0.2.11.

knn_hybrid_search(query: str | None = None, k: int | None = 10, query_vector: List[float] | None = None, model_id: str | None = None, size: int | None = 10, source: bool | None = True, knn_boost: float | None = 0.9, query_boost: float | None = 0.1, fields: List[Mapping[str, Any]] | Tuple[Mapping[str, Any], ...] | None = None, page_content: str | None = 'text') → List[Tuple[Document, float]]

Perform a hybrid k-NN and text search on the Elasticsearch index.

Parameters:

• query (str, optional) – The query text to search for.

• k (int, optional) – The number of nearest neighbors to return.

• query_vector (List[float], optional) – The query vector to search for.

• model_id (str, optional) – The ID of the model to use for transforming the query text into a vector.

• size (int, optional) – The number of search results to return.

• source (bool, optional) – Whether to return the source of the search results.

• knn_boost (float, optional) – The boost value to apply to the k-NN search results.

• query_boost (float, optional) – The boost value to apply to the text search results.

• fields (List[Mapping[str, Any]], optional) – The fields to return in the search results.

• page_content (str, optional) – The name of the field that contains the page content.

Returns:

A list of tuples, where each tuple contains a Document object and a score.

Return type:

List[Tuple[Document, float]]

knn_search(query: str | None = None, k: int | None = 10, query_vector: List[float] | None = None, model_id: str | None = None, size: int | None = 10, source: bool | None = True, fields: List[Mapping[str, Any]] | Tuple[Mapping[str, Any], ...] | None = None, page_content: str | None = 'text') → List[Tuple[Document, float]]

Perform a k-NN search on the Elasticsearch index.

Parameters:

• query (str, optional) – The query text to search for.

• k (int, optional) – The number of nearest neighbors to return.

• query_vector (List[float], optional) – The query vector to search for.

• model_id (str, optional) – The ID of the model to use for transforming the query text into a vector.

• size (int, optional) – The number of search results to return.

• source (bool, optional) – Whether to return the source of the search results.

• fields (List[Mapping[str, Any]], optional) – The fields to return in the search results.

• page_content (str, optional) – The name of the field that contains the page content.

Returns:

A list of tuples, where each tuple contains a Document object and a score.

Return type:

List[Tuple[Document, float]]

max_marginal_relevance_search(query: str, k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, **kwargs: Any) → List[Document]

Return docs selected using the maximal marginal relevance.

Maximal marginal relevance optimizes for similarity to query AND diversity among selected documents.

Parameters:

• query (str) – Text to look up documents similar to.

• k (int) – Number of Documents to return. Defaults to 4.

• fetch_k (int) – Number of Documents to fetch to pass to MMR algorithm. Default is 20.

• lambda_mult (float) – Number between 0 and 1 that determines the degree of diversity among the results with 0 corresponding to maximum diversity and 1 to minimum diversity. Defaults to 0.5.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents selected by maximal marginal relevance.

Return type:

List[Document]

max_marginal_relevance_search_by_vector(embedding: List[float], k: int = 4, fetch_k: int = 20, lambda_mult: float = 0.5, **kwargs: Any) → List[Document]

Return docs selected using the maximal marginal relevance.

Maximal marginal relevance optimizes for similarity to query AND diversity among selected documents.

Parameters:

• embedding (List[float]) – Embedding to look up documents similar to.

• k (int) – Number of Documents to return. Defaults to 4.

• fetch_k (int) – Number of Documents to fetch to pass to MMR algorithm. Default is 20.

• lambda_mult (float) – Number between 0 and 1 that determines the degree of diversity among the results with 0 corresponding to maximum diversity and 1 to minimum diversity. Defaults to 0.5.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents selected by maximal marginal relevance.

Return type:

List[Document]

search(query: str, search_type: str, **kwargs: Any) → List[Document]

Return docs most similar to query using a specified search type.

Parameters:

• query (str) – Input text

• search_type (str) – Type of search to perform. Can be “similarity”, “mmr”, or “similarity_score_threshold”.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents most similar to the query.

Raises:

ValueError – If search_type is not one of “similarity”, “mmr”, or “similarity_score_threshold”.

Return type:

List[Document]

similarity_search(query: str, k: int = 4, filter: dict | None = None, **kwargs: Any) → List[Document]

Pass through to knn_search

Parameters:

• query (str) –

• k (int) –

• filter (dict | None) –

• kwargs (Any) –

Return type:

List[Document]

similarity_search_by_vector(embedding: List[float], k: int = 4, **kwargs: Any) → List[Document]

Return docs most similar to embedding vector.

Parameters:

• embedding (List[float]) – Embedding to look up documents similar to.

• k (int) – Number of Documents to return. Defaults to 4.

• **kwargs (Any) – Arguments to pass to the search method.

Returns:

List of Documents most similar to the query vector.

Return type:

List[Document]

similarity_search_with_relevance_scores(query: str, k: int = 4, **kwargs: Any) → List[Tuple[Document, float]]

Return docs and relevance scores in the range [0, 1].

0 is dissimilar, 1 is most similar.

Parameters:

• query (str) – Input text.

• k (int) – Number of Documents to return. Defaults to 4.

• **kwargs (Any) –

  kwargs to be passed to similarity search. Should include: score_threshold: Optional, a floating point value between 0 to 1 to

  filter the resulting set of retrieved docs.

Returns:

List of Tuples of (doc, similarity_score).

Return type:

List[Tuple[Document, float]]

similarity_search_with_score(query: str, k: int = 10, **kwargs: Any) → List[Tuple[Document, float]]

Pass through to knn_search including score

Parameters:

• query (str) –

• k (int) –

• kwargs (Any) –

Return type:

List[Tuple[Document, float]]