langchain_community.vectorstores.pgvecto_rs.PGVecto_rs

class langchain_community.vectorstores.pgvecto_rs.PGVecto_rs(embedding: Embeddings, dimension: int, db_url: str, collection_name: str, new_table: bool = False)

VectorStore backed by pgvecto_rs.

Initialize a PGVecto_rs vectorstore.

Parameters

• embedding (Embeddings) – Embeddings to use.

• dimension (int) – Dimension of the embeddings.

• db_url (str) – Database URL.

• collection_name (str) – Name of the collection.

• new_table (bool) – Whether to create a new table or connect to an existing one.

• true (If) –

• exists (the table will be dropped if) –

• recreated. (then) –

• False. (Defaults to) –

Attributes

embeddings

Access the query embedding object if available.

Methods

__init__(embedding, dimension, db_url, ...)	Initialize a PGVecto_rs vectorstore.
aadd_documents(documents, **kwargs)	Run more documents through the embeddings and add to the vectorstore.
aadd_texts(texts[, metadatas])	Run more texts through the embeddings and add to the vectorstore.
add_documents(documents, **kwargs)	Run more documents through the embeddings and add to the vectorstore.
add_texts(texts[, metadatas])	Run more texts through the embeddings and add to the vectorstore.
adelete([ids])	Delete by vector ID or other criteria.
afrom_documents(documents, embedding, **kwargs)	Return VectorStore initialized from documents and embeddings.
afrom_texts(texts, embedding[, metadatas])	Return VectorStore initialized from texts and embeddings.
amax_marginal_relevance_search(query[, k, ...])	Return docs selected using the maximal marginal relevance.
amax_marginal_relevance_search_by_vector(...)	Return docs selected using the maximal marginal relevance.
as_retriever(**kwargs)	Return VectorStoreRetriever initialized from this VectorStore.
asearch(query, search_type, **kwargs)	Return docs most similar to query using specified search type.
asimilarity_search(query[, k])	Return docs most similar to query.
asimilarity_search_by_vector(embedding[, k])	Return docs most similar to embedding vector.
asimilarity_search_with_relevance_scores(query)	Return docs and relevance scores in the range [0, 1], asynchronously.
asimilarity_search_with_score(*args, **kwargs)	Run similarity search with distance asynchronously.
delete([ids])	Delete by vector ID or other criteria.
from_collection_name(embedding, db_url, ...)	Create new empty vectorstore with collection_name.
from_documents(documents, embedding[, ...])	Return VectorStore initialized from documents.
from_texts(texts, embedding[, metadatas, ...])	Return VectorStore initialized from texts and optional metadatas.
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 specified search type.
similarity_search(query[, k, distance_func])	Return docs most similar to query.
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, ...])	Run similarity search with distance.
similarity_search_with_score_by_vector(...)	Return docs most similar to query vector, with its score.

__init__(embedding: Embeddings, dimension: int, db_url: str, collection_name: str, new_table: bool = False) → None

Initialize a PGVecto_rs vectorstore.

Parameters

• embedding (Embeddings) – Embeddings to use.

• dimension (int) – Dimension of the embeddings.

• db_url (str) – Database URL.

• collection_name (str) – Name of the collection.

• new_table (bool) – Whether to create a new table or connect to an existing one.

• true (If) –

• exists (the table will be dropped if) –

• recreated. (then) –

• False. (Defaults to) –

Return type

None

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

Run more documents through the embeddings and add to the vectorstore.

Parameters

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

• documents (List[Document]) –

• kwargs (Any) –

Returns

List of IDs of the added texts.

Return type

List[str]

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

Run more texts through the embeddings and add to the vectorstore.

Parameters

• texts (Iterable[str]) –

• metadatas (Optional[List[dict]]) –

• kwargs (Any) –

Return type

List[str]

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

Run more documents through the embeddings and add to the vectorstore.

Parameters

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

• kwargs (Any) –

Returns

List of ids of the added documents.

Return type

List[str]

add_texts(texts: Iterable[str], metadatas: Optional[List[dict]] = None, **kwargs: Any) → List[str]

Run more texts through the embeddings and add to the vectorstore.

Parameters

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

• metadatas (Optional[List[dict]]) – Optional list of metadatas associated with the texts.

• kwargs (Any) – vectorstore specific parameters

Returns

List of ids of the added texts.

Return type

List[str]

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

Delete by vector ID or other criteria.

Parameters

• ids (Optional[List[str]]) – List of ids to delete.

• **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

Return VectorStore initialized from documents and embeddings.

Parameters

• documents (List[Document]) –

• embedding (Embeddings) –

• kwargs (Any) –

Return type

VST

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

Return VectorStore initialized from texts and embeddings.

Parameters

• texts (List[str]) –

• embedding (Embeddings) –

• metadatas (Optional[List[dict]]) –

• kwargs (Any) –

Return type

VST

async amax_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.

• 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]

Return docs selected using the maximal marginal relevance.

Parameters

• embedding (List[float]) –

• k (int) –

• fetch_k (int) –

• lambda_mult (float) –

• kwargs (Any) –

Return type

List[Document]

as_retriever(**kwargs: Any) → VectorStoreRetriever

Return VectorStoreRetriever initialized from this VectorStore.

Parameters

• 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

• kwargs (Any) –

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]

Return docs most similar to query using specified search type.

Parameters

• query (str) –

• search_type (str) –

• kwargs (Any) –

Return type

List[Document]

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

Return docs most similar to query.

Parameters

• query (str) –

• k (int) –

• kwargs (Any) –

Return type

List[Document]

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

Return docs most similar to embedding vector.

Parameters

• embedding (List[float]) –

• k (int) –

• kwargs (Any) –

Return type

List[Document]

async asimilarity_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], asynchronously.

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]]

Run similarity search with distance asynchronously.

Parameters

• args (Any) –

• kwargs (Any) –

Return type

List[Tuple[Document, float]]

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

Delete by vector ID or other criteria.

Parameters

• ids (Optional[List[str]]) – List of ids to delete.

• **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_collection_name(embedding: Embeddings, db_url: str, collection_name: str) → PGVecto_rs

Create new empty vectorstore with collection_name. Or connect to an existing vectorstore in database if exists. Arguments should be the same as when the vectorstore was created.

Parameters

• embedding (Embeddings) –

• db_url (str) –

• collection_name (str) –

Return type

PGVecto_rs

classmethod from_documents(documents: List[Document], embedding: Embeddings, db_url: str = '', collection_name: str = '000bb55a8e6644b6a1174bf79c5272c7', **kwargs: Any) → PGVecto_rs

Return VectorStore initialized from documents.

Parameters

• documents (List[Document]) –

• embedding (Embeddings) –

• db_url (str) –

• collection_name (str) –

• kwargs (Any) –

Return type

PGVecto_rs

classmethod from_texts(texts: List[str], embedding: Embeddings, metadatas: Optional[List[dict]] = None, db_url: str = '', collection_name: str = '3f7d4107482b48ef88705f41df3a0a25', **kwargs: Any) → PGVecto_rs

Return VectorStore initialized from texts and optional metadatas.

Parameters

• texts (List[str]) –

• embedding (Embeddings) –

• metadatas (Optional[List[dict]]) –

• db_url (str) –

• collection_name (str) –

• kwargs (Any) –

Return type

PGVecto_rs

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.

• 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]

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.

• 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]

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

Return docs most similar to query using specified search type.

Parameters

• query (str) –

• search_type (str) –

• kwargs (Any) –

Return type

List[Document]

similarity_search(query: str, k: int = 4, distance_func: Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos'] = 'sqrt_euclid', **kwargs: Any) → List[Document]

Return docs most similar to query.

Parameters

• query (str) –

• k (int) –

• distance_func (Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos']) –

• kwargs (Any) –

Return type

List[Document]

similarity_search_by_vector(embedding: List[float], k: int = 4, distance_func: Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos'] = 'sqrt_euclid', filter: Optional[Any] = None, **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.

• distance_func (Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos']) –

• filter (Optional[Any]) –

• kwargs (Any) –

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 = 4, distance_func: Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos'] = 'sqrt_euclid', **kwargs: Any) → List[Tuple[Document, float]]

Run similarity search with distance.

Parameters

• query (str) –

• k (int) –

• distance_func (Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos']) –

• kwargs (Any) –

Return type

List[Tuple[Document, float]]

similarity_search_with_score_by_vector(query_vector: List[float], k: int = 4, distance_func: Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos'] = 'sqrt_euclid', filter: Union[None, Dict[str, Any], Any] = None, **kwargs: Any) → List[Tuple[Document, float]]

Return docs most similar to query vector, with its score.

Parameters

• query_vector (List[float]) –

• k (int) –

• distance_func (Literal['sqrt_euclid', 'neg_dot_prod', 'ned_cos']) –

• filter (Union[None, Dict[str, Any], Any]) –

• kwargs (Any) –

Return type

List[Tuple[Document, float]]

Examples using PGVecto_rs

• Run tests with shell: