Document Stores

Document stores contain ingested document chunks, which we call Node objects.

See the API Reference for more details.

Simple Document Store

By default, the SimpleDocumentStore stores Node objects in-memory. They can be persisted to (and loaded from) disk by calling docstore.persist() (and SimpleDocumentStore.from_persist_path(...) respectively).

MongoDB Document Store

We support MongoDB as an alternative document store backend that persists data as Node objects are ingested.

from llama_index.storage.docstore import MongoDocumentStore
from llama_index.node_parser import SimpleNodeParser

# create parser and parse document into nodes 
parser = SimpleNodeParser()
nodes = parser.get_nodes_from_documents(documents)

# create (or load) docstore and add nodes
docstore = MongoDocumentStore.from_uri(uri="<mongodb+srv://...>")
docstore.add_documents(nodes)

# create storage context
storage_context = StorageContext.from_defaults(docstore=docstore)

# build index
index = VectorStoreIndex(nodes, storage_context=storage_context)

Under the hood, MongoDocumentStore connects to a fixed MongoDB database and initializes new collections (or loads existing collections) for your nodes.

Note: You can configure the db_name and namespace when instantiating MongoDocumentStore, otherwise they default to db_name="db_docstore" and namespace="docstore".

Note that it’s not necessary to call storage_context.persist() (or docstore.persist()) when using an MongoDocumentStore since data is persisted by default.

You can easily reconnect to your MongoDB collection and reload the index by re-initializing a MongoDocumentStore with an existing db_name and collection_name.