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The community member is trying to retrieve nodes from a VectorStoreIndex, but index.docstore.docs.values() is always an empty dictionary. Other community members suggest that the issue may be related to using a third-party vector store, such as ChromaVectorStore. They provide some guidance on how to retrieve the nodes, including using vector_store._collection.get() and setting the store_nodes_override parameter to True when creating the VectorStoreIndex. However, there is no explicitly marked answer in the comments.

aandy

How do I get nodes from an existing VectorStoreIndex?

index.docstore.docs.values() is always an empty dictionary…

14 comments

WWhiteFang_Jr

Are you using third party vector store?

aandy

Im using chromavectorstore

aandy

vector_store = ChromaVectorStore(chroma_collection = chroma_collection)
index=VectorStoreIndex.from_vector_store(vector_store, embed_model = embed_model)

aandy

@WhiteFang_Jr

aandy

hmmm i figured out how to do it for Chroma by vector_store._collection.get()

aandy

but im trying to figure out how to do it with the index object which is a VectorStoreIndez

WWhiteFang_Jr

If it is a vectorStoreIndex, once indexing is completed you'll have to persist the index in case you want to have the nodes back when loading from local directory.

aandy

@WhiteFang_Jr the index is persisted. whats the correct method to retrieve the nodes from the persist directory?

LLogan M

Third party vector stores disable the docstore by default to simplify storage. You can override this, or use a chroma client directly to get everything

LLogan M

there is also a get_nodes() function for chroma vector store, but you need to provide either node ids or filters

aandy

@Logan M thanks for the response. what is the parameter that disables the docstore in chroma?

LLogan M

Sorry, you'd want the parameter to enable it (but note then you should also handle saving/reloading the docstore as well)

VectorStoreIndex(..., store_nodes_override=True)

aandy

@Logan M Nice this worked. Thank you!
When using VectorStoreIndex.from_documents() is it possible to extract the nodes here?

LLogan M

Probably some hacky way, but I would just create the nodes first

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