Semantic Search Node

The semantic search nodes embeds and queries documents semantically at run time. In contrast to the knowledge base, which is a permanent store of data, documents embedded using the semantic search node are immediately deleted after the pipeline finishes running.

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Node Inputs

1. Search Query: The query that will be used to search the embedded documents semantically for relevant pieces
   • Type: Text
2. Documents for Search: The text that will be semantically searched
   • Type: Text

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Node Parameters

On the face of the node:

1. Embedding model: The embedding model to use to embed the documents
   • Type: Dropdown

In the gear:

1. Max chunks per query: the maximum number of pieces of data to be returned per query
2. Enable Filter: enable the ability to write a metadata filter
3. Enable Context: enable a text field to provide additional context for the search query
4. Re-rank documents: Performs an additional reranking step to reorder the documents by relevance to the query
5. Score Cutoff: The minimum relevancy score (between 0 and 1) that each piece of data will have semantically to the query
6. Retrieval Unit: Return the most relevant chunks (text content) or Documents (will return document metadata)
7. Transform Query: Transform the query for better results
8. Answer Multiple Questions: Extract separate questions from the query and retrieve content separately for each question to improve search performance
9. Expand Query: Expand query to improve semantic search
10. Do Advanced QA: Use additional LLM calls to analyze each document to improve answer correctness
11. Show Immediate Steps: Display the process the knowledge base is conducting at a given time in the chatUI
12. Format Context for an LLM: Do an additional LLM call to format output

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Node Outputs

If Retrieval Unit is set to Chunks

1. Chunks: Semantically similar chunks retrieved from the documents
   • Type: List<Text>
   • Example usage: {{semantic_search_0.chunks}}

If Retrieval Unit is set to Documents

1. Documents: Metadata for semantically similar documents retrieved from the documents
   • Type: List<Text>
   • Example usage: {{semantic_search_0.documents}}

If “Do Advanced QA” is enabled

1. Response: A direct answer to the query
   • Type: Text
   • Example usage: {{semantic_search_0.response}}

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Considerations

• Use a semantic search node when your pipeline loads new data at run time for querying. Use a Knowledge Base Reader node when you want to query previously loaded data that has already been loaded.
• If the semantic search node is not returning relevant information to a query, try increasing the number of max chunks per query in the gear of the knowledge base.
• For debugging purposes, you may attach an output node to the semantic search node to view the chunks that are returned for the query.

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Example

The below example is a pipeline that allows the user to ask a question to a website. Hence, it has two inputs: the question (input_1) and the URL of the website (input_2).

The website link is passed to the scrape URL node, which scrapes the website and passes the content to the “Documents for Search” input on the semantic search node. Input_1 (the user question) is passed to the Search Query input of the semantic search node.

Then, the OpenAI node both receives the user question (input_1) and the semantic similar chunks (semantic_search_1) to generate a response that is displayed by the output node.