run-llama / llama_index

LlamaIndex is a data framework for your LLM applications
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Query a vector database against one question to return nodes, then query llm with another question against those nodes. #13268

Closed Jez77 closed 2 weeks ago

Jez77 commented 4 months ago

Question Validation

Question

I am very new to programming and Llama_index, so please bear with me.

I wanted to query a vector database on the basis of one question and return a set of nodes, then provide those nodes with the query plus some further info to an llm to provide a final answer. I am having real trouble understanding how to do this and everything i try ends in errors or fails.

I am not entirely sure whether this needs to be a two step process: (1) retrieve the nodes; (2) run the final query against the retrieved nodes. Or whether I could achieve the same end result with a separate query and system prompt. I don't really mind, I just want to retrieve a list of nodes on the basis of a question, then run a separate query against that node list.

the instruction to answer in spanish is an example, and i have a much more complex instruction i want to give the LLM. So i don't not want the query to the vector database to include the "answer in spanish" aspect.

This is the code I have so far. I would be very grateful for help.

from dotenv import load_dotenv import os

from llama_index.embeddings.openai import OpenAIEmbedding from pinecone import Pinecone, ServerlessSpec from llama_index.vector_stores.pinecone import PineconeVectorStore from llama_index.core import VectorStoreIndex, get_response_synthesizer, ServiceContext, StorageContext from llama_index.core.retrievers import VectorIndexRetriever from llama_index.core.query_engine import RetrieverQueryEngine from llama_index.llms.anthropic import Anthropic from llama_index.core import Settings import streamlit as st

os.environ["HF_HUB_DISABLE_SYMLINKS_WARNING"] = "1" load_dotenv()

pc = Pinecone(api_key=os.environ['PINECONE_API_KEY'])

llm = Anthropic(model="claude-3-sonnet-20240229", max_tokens=2048, temperature=0.2)

embed_model = OpenAIEmbedding(model="text-embedding-3-large", embed_batch_size=100)

Settings.llm = llm Settings.embed_model = embed_model

pinecone_index = pc.Index(name=os.environ['PINECONE_NAME']) vector_store = PineconeVectorStore(pinecone_index=pinecone_index)

Settings.llm = llm index = VectorStoreIndex.from_vector_store(vector_store=vector_store)

retriever = VectorIndexRetriever( index=index, similarity_top_k=1, )

response_synthesizer = get_response_synthesizer()

query_engine = RetrieverQueryEngine( retriever=retriever, response_synthesizer=response_synthesizer, )

st.title("Hi, i'm a bot, try me")

question = st.text_input("Enter your question:")

if st.button("Get Answer"): response = query_engine.query( f"""
Answer in spanish. Question: {question} """ )

st.markdown(response, unsafe_allow_html=True)
dosubot[bot] commented 4 months ago

To refine your approach and address the issues you're encountering, let's break down the process into clearer steps, focusing on separating the retrieval of nodes based on your initial question from processing those nodes with a more complex instruction for the LLM.

Step 1: Retrieve Nodes Based on a Question

First, you need to retrieve nodes relevant to your initial question. This involves querying your vector database with the question's embedding and retrieving a set of nodes. The code snippet provided in the previous message outlines how to perform this retrieval, but let's ensure it's integrated correctly in your workflow. You'll need to generate an embedding for your initial question and use that embedding to query the vector database:

# Assuming `question` is your initial question
query_embedding = embed_model.embed([question])[0]  # Embed the question

# Create a query for the vector store
query = VectorStoreQuery(
    query_embedding=query_embedding,  # Use the embedding of your initial question
    similarity_top_k=10,  # Adjust based on how many nodes you want to retrieve
    mode=VectorStoreQueryMode.DEFAULT
)

# Retrieve nodes
nodes = retriever.retrieve(query)

Ensure you have the correct setup for embedding your question and that retriever.retrieve(query) is correctly implemented to handle the query and return the desired nodes.

Step 2: Process Retrieved Nodes with a Complex Instruction

After retrieving the nodes, you'll want to process them with a separate, more complex instruction for the LLM. This step is crucial for applying your specific logic or instructions to the data obtained from the nodes. The processing might involve filtering the nodes, extracting specific information, or preparing a new query for the LLM based on the nodes' data:

# Example function to process nodes
def process_retrieved_nodes(nodes):
    # Your logic here to process the nodes, apply further queries, etc.
    # This could involve generating a new query for the LLM based on the nodes' data
    pass

final_results = process_retrieved_nodes(nodes)

This function is a placeholder for your logic. Depending on your application, you might generate a new query for the LLM or perform other data processing tasks based on the nodes you've retrieved.

Troubleshooting and Further Steps

By following these steps and ensuring each part of your code is correctly implemented, you should be able to achieve your goal of querying a vector database with one question to retrieve nodes and then querying those nodes with another question. If specific errors or challenges arise, sharing those details can help in providing more targeted advice.

#### Details **About Dosu** This response is meant to be useful and save you time. It is **not meant to be a precise solution**, but rather a starting point for your own research. Help me be more useful! Please leave a πŸ‘ if this is helpful and πŸ‘Ž if it is irrelevant.

To continue the conversation, mention @dosu.

Jez77 commented 4 months ago

@dosu

Apologies but there seems to be problems with the provided code:

First issue. In your code you use "embed_model.embed". That returns an error for me: AttributeError: 'OpenAIEmbedding' object has no attribute 'embed'.

Second issue I can get round the first issue by using "embed_model.get_text_embedding(question)" but then i get another error on nodes = retriever.retrieve(query) because i think what's returned is a vector rather than a string.

Third issue Even if i get to a point where a node list is returned please could you tell me how to supply that node list to the llm with the query. I tend to use the response synthesizer to obtain a response, what should I use here?

dosubot[bot] commented 4 months ago

Let's address each of your concerns step by step to ensure you can move forward with your project effectively:

First Issue: AttributeError with OpenAIEmbedding

The error you encountered is due to calling a non-existent method on the OpenAIEmbedding object. It's good that you found a workaround by using embed_model.get_text_embedding(question). This method is indeed the correct approach for obtaining the text embedding from your question. It's important to always refer to the most current documentation of the library you're using to ensure you're calling the right methods.

Second Issue: Error on nodes = retriever.retrieve(query)

After you obtain the embedding with get_text_embedding, the next step is to ensure that the query you're making to the vector database is correctly formatted. The error suggests there might be a mismatch in the expected input type for the retriever.retrieve(query) method. Since you're working with embeddings (which are typically arrays or lists of numbers), ensure that the query is properly constructed to match the expected format of the retrieval method. If the method expects a vector, you should not convert this vector into a string; instead, pass it directly in the format expected by the VectorIndexRetriever.

Third Issue: Supplying Node List to LLM

Once you have the node list, the challenge is to format these nodes for the LLM to process. This step involves structuring the nodes in a way that they can be understood by the LLM, potentially as a list of items with relevant information extracted from each node. You can then incorporate this structured information into your query for the LLM. If you're using a response synthesizer, it needs to be capable of handling this structured input. The exact method to use here depends on how your response synthesizer is implemented and how it expects input to be formatted. Typically, you would construct a string or a structured object that includes both the nodes' information and your complex instruction, then pass this as input to the LLM or synthesizer.

Processing Retrieved Nodes with a Complex Instruction

For processing the nodes with a complex instruction, you'll need to implement logic that formats a new query for the LLM based on the information extracted from the nodes. This might involve creating a summary of the nodes' information or extracting key details to form a new query that includes your complex instructions for the LLM.

Remember, integration and data type compatibility between different parts of your workflow are crucial. Each function and method in your code expects inputs in a certain format, and ensuring these expectations are met is key to resolving the issues you're facing. If the documentation is unclear or you're unsure about the inputs and outputs of certain methods, looking for examples or reaching out for community support can be very helpful.

#### Details **About Dosu** This response is meant to be useful and save you time. It is **not meant to be a precise solution**, but rather a starting point for your own research. Help me be more useful! Please leave a πŸ‘ if this is helpful and πŸ‘Ž if it is irrelevant.

To continue the conversation, mention @dosu.

Jez77 commented 4 months ago

@dosu

But why do i have to worry about formatting the node list? When using retrieverQueryEngine, the llm is passed in a set of nodes and the llm and a response is generated. No manual formatting of the nodes is needed.

All i want to do is pass in a set of nodes I already retrieved in response to the query "question". I now just want that node list to be provided to the llm to generate a response to a new question.

Can't retrieverQueryEngine or something similar receive the list of nodes generated?

ALTERNATIVE As an alternative, would it help to use a system prompt? Could i return a list of nodes based on a question; then additionally provide the system prompt to the query engine, to generate the final response?

dosubot[bot] commented 4 months ago

To directly address your concerns about passing a set of nodes to the LLM for generating a response to a new question, you can indeed use the RetrieverQueryEngine for this purpose without needing to manually format the node list. The process involves two main steps: retrieving nodes based on your initial query and then synthesizing a response based on those nodes for a new question. Here's how you can do it:

  1. Retrieve Nodes: Use the RetrieverQueryEngine to retrieve nodes relevant to your initial question. This step is straightforward and involves using the retrieve method with your query.

  2. Generate Response: Once you have the nodes, you can pass them along with a new question to the RetrieverQueryEngine to synthesize a response. This is done by using the synthesize method, which takes the nodes you retrieved and the new question to generate the final response.

This approach eliminates the need for manual formatting of the node list, as the RetrieverQueryEngine handles the integration between the retrieval and synthesis phases seamlessly.

Regarding the issues you've encountered:

For an alternative approach using a system prompt, this would typically involve structuring your query in a way that guides the LLM to consider the nodes in generating a response. However, the primary method using RetrieverQueryEngine should suffice for your needs, as it's designed to handle the process you're describing.

#### Details **Sources** - [llama-index-legacy/llama_index/legacy/query_engine/retriever_query_engine.py](https://github.com/run-llama/llama_index/blob/main/llama-index-legacy/llama_index/legacy/query_engine/retriever_query_engine.py) - [llama-index-integrations/embeddings/llama-index-embeddings-openai/llama_index/embeddings/openai/base.py](https://github.com/run-llama/llama_index/blob/main/llama-index-integrations/embeddings/llama-index-embeddings-openai/llama_index/embeddings/openai/base.py) - [llama-index-legacy/llama_index/legacy/embeddings/openai.py](https://github.com/run-llama/llama_index/blob/main/llama-index-legacy/llama_index/legacy/embeddings/openai.py) - [llama-index-core/llama_index/core/query_engine/retriever_query_engine.py](https://github.com/run-llama/llama_index/blob/main/llama-index-core/llama_index/core/query_engine/retriever_query_engine.py) - [llama-index-legacy/llama_index/legacy/embeddings/utils.py](https://github.com/run-llama/llama_index/blob/main/llama-index-legacy/llama_index/legacy/embeddings/utils.py) - [llama-index-legacy/llama_index/legacy/embeddings/loading.py](https://github.com/run-llama/llama_index/blob/main/llama-index-legacy/llama_index/legacy/embeddings/loading.py) - [llama-index-legacy/tests/embeddings/test_base.py](https://github.com/run-llama/llama_index/blob/main/llama-index-legacy/tests/embeddings/test_base.py) - [llama-index-core/llama_index/core/prompts/prompts.py](https://github.com/run-llama/llama_index/blob/main/llama-index-core/llama_index/core/prompts/prompts.py)
**About Dosu** This response is meant to be useful and save you time. It is **not meant to be a precise solution**, but rather a starting point for your own research. Help me be more useful! Please leave a πŸ‘ if this is helpful and πŸ‘Ž if it is irrelevant.

To continue the conversation, mention @dosu.

logan-markewich commented 4 months ago

@Jez77 You can use a retriever with a response synthesizer

from llama_index.core import VectorStoreIndex, get_response_synthesizer
from llama_index.core.retrievers import VectorIndexRetriever
from llama_index.core.query_engine import RetrieverQueryEngine

# build index
index = VectorStoreIndex.from_documents(documents)

# configure retriever
retriever = VectorIndexRetriever(
    index=index,
    similarity_top_k=2,
)

# configure response synthesizer
response_synthesizer = get_response_synthesizer(
    response_mode="compact", 
)

nodes = retriever.retrieve("test")

response = response_synthesizer.synthesize("test", nodes=nodes)
Jez77 commented 3 months ago

Thanks Logan, you're a star.