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.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://...>")

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

# build index
index = GPTVectorStoreIndex(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.