Can we use Reciprocal rank fusion (RRF) as an alternative to Rerank models to save costs?

[jamie0725]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

Hi, currently, if we want to use multi-path retrieval or retrieve from multiple knowledge bases, we have to configure a Rerank API, which not only increases costs but also security concerns (because we need to send our data to API vendors).

I can see the value of Rerank models, but I see them more of an advanced setting, rather than a necessity.

For example, can we add a feature to support RRF in the reranking stage?

score = 0.0
for q in queries:
    if d in result(q):
        score += 1.0 / ( k + rank( result(q), d ) )
return score

# where
# k is a ranking constant
# q is a query in the set of queries
# d is a document in the result set of q
# result(q) is the result set of q
# rank( result(q), d ) is d's rank within the result(q) starting from 1

2. Additional context or comments

No response

3. Can you help us with this feature?

• [ ] I am interested in contributing to this feature.