AstraDB

DataStax Astra DB is a serverless vector-capable database built on Cassandra and made conveniently available through an easy-to-use JSON API.

Overview

The AstraDB Document Loader returns a list of Langchain Documents from an AstraDB database.

The Loader takes the following parameters:

• api_endpoint: AstraDB API endpoint. Looks like https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com
• token: AstraDB token. Looks like AstraCS:6gBhNmsk135....
• collection_name : AstraDB collection name
• namespace: (Optional) AstraDB namespace
• filter_criteria: (Optional) Filter used in the find query
• projection: (Optional) Projection used in the find query
• find_options: (Optional) Options used in the find query
• nb_prefetched: (Optional) Number of documents pre-fetched by the loader
• extraction_function: (Optional) A function to convert the AstraDB document to the LangChain page_content string. Defaults to json.dumps

The following metadata is set to the LangChain Documents metadata output:

{
    metadata : {
        "namespace": "...", 
        "api_endpoint": "...", 
        "collection": "..."
    }
}

Load documents with the Document Loader

from langchain_community.document_loaders import AstraDBLoader

from getpass import getpass

ASTRA_DB_API_ENDPOINT = input("ASTRA_DB_API_ENDPOINT = ")
ASTRA_DB_APPLICATION_TOKEN = getpass("ASTRA_DB_APPLICATION_TOKEN = ")

loader = AstraDBLoader(
    api_endpoint=ASTRA_DB_API_ENDPOINT,
    token=ASTRA_DB_APPLICATION_TOKEN,
    collection_name="movie_reviews",
    projection={"title": 1, "reviewtext": 1},
    find_options={"limit": 10},
)

docs = loader.load()

docs[0]

Document(page_content='{"_id": "659bdffa16cbc4586b11a423", "title": "Dangerous Men", "reviewtext": "\\"Dangerous Men,\\" the picture\'s production notes inform, took 26 years to reach the big screen. After having seen it, I wonder: What was the rush?"}', metadata={'namespace': 'default_keyspace', 'api_endpoint': 'https://01234567-89ab-cdef-0123-456789abcdef-us-east1.apps.astra.datastax.com', 'collection': 'movie_reviews'})