Create an PGVectorStore instance from documents.
afrom_documents(
cls: type[PGVectorStore],
documents: list[Document],
embedding: Embeddings,
engine: PGEngine,
table_name: str,
schema_name: str = 'public',
ids: Optional[list] = None,
content_column: str = 'content',
embedding_column: str = 'embedding',
metadata_columns: Optional[list[str]] = None,
ignore_metadata_columns: Optional[list[str]] = None,
id_column: str = 'langchain_id',
metadata_json_column: str = 'langchain_metadata',
distance_strategy: DistanceStrategy = DEFAULT_DISTANCE_STRATEGY,
k: int = 4,
fetch_k: int = 20,
lambda_mult: float = 0.5,
index_query_options: Optional[QueryOptions] = None,
hybrid_search_config: Optional[HybridSearchConfig] = None,
**kwargs: Any = {}
) -> PGVectorStore| Name | Type | Description |
|---|---|---|
documents* | list[Document] | Documents to add to the vector store. |
embedding* | Embeddings | Text embedding model to use. |
engine* | PGEngine | Connection pool engine for managing connections to postgres database. |
table_name* | str | Name of an existing table. |
schema_name | str | Default: 'public'Name of the database schema. Defaults to "public". |
ids | Optional[list] | Default: None(Optional[list]): List of IDs to add to table records. Defaults to None. |
content_column | str | Default: 'content'Column that represent a Document's page_content. Defaults to "content". |
embedding_column | str | Default: 'embedding'Column for embedding vectors. The embedding is generated from the document value. Defaults to "embedding". |
metadata_columns | list[str] | Default: NoneColumn(s) that represent a document's metadata. Defaults to an empty list. |
ignore_metadata_columns | Optional[list[str]] | Default: NoneColumn(s) to ignore in pre-existing tables for a document's metadata. Can not be used with metadata_columns. Defaults to None. |
id_column | str | Default: 'langchain_id'Column that represents the Document's id. Defaults to "langchain_id". |
metadata_json_column | str | Default: 'langchain_metadata'Column to store metadata as JSON. Defaults to "langchain_metadata". |
distance_strategy | DistanceStrategy | Default: DEFAULT_DISTANCE_STRATEGYDistance strategy to use for vector similarity search. Defaults to COSINE_DISTANCE. |
k | int | Default: 4Number of Documents to return from search. Defaults to 4. |
fetch_k | int | Default: 20Number of Documents to fetch to pass to MMR algorithm. |
lambda_mult | float | Default: 0.5Number 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. |
index_query_options | QueryOptions | Default: NoneIndex query option. |
hybrid_search_config | HybridSearchConfig | Default: NoneHybrid search configuration. Defaults to None. |