We are using pgvector and when

Do you have it set in your script or do you wish to change it?

The vector index has a default top k of 2, but you can change this.

index.as_query_engine(similarity_top_k=3)

Thanks @Logan M

So @Logan M What will be the difference in performance , recall etc.. when we change top_k ? Any suggestions/ best practices around this topic

Top-k increases the number of document sent to the LLM. But this can both a) increase latency and b) sometimes increase hallucination if too many documents are retrieved

One approach often used is, people might set a high top-k, and then use a reranker to filter back down to a smaller set of relevant documents

Thanks @Logan M You are awesome !! Always helpful !!