Retrieve
Background
DSPy supports retrieval through the Retrieve module that serves to process user queries and output relevant passages from retrieval corpuses. This module ties in with the DSPy-supported Retrieval Model Clients which are retrieval servers that users can utilize to retrieve information for information retrieval tasks.
Instantiating Retrieve
Retrieve is simply instantiate by a user-defined k number of retrieval passages to return for a query.
class Retrieve(Parameter):
def __init__(self, k=3):
self.stage = random.randbytes(8).hex()
self.k = k
Additionally, configuring a Retrieval model client or server through dspy.configure allows for user retrieval in DSPy programs through internal calls from Retrieve.
#Example Usage
#Define a retrieval model server to send retrieval requests to
colbertv2_wiki17_abstracts = dspy.ColBERTv2(url='http://20.102.90.50:2017/wiki17_abstracts')
#Configure retrieval server internally
dspy.settings.configure(rm=colbertv2_wiki17_abstracts)
#Define Retrieve Module
retriever = dspy.Retrieve(k=3)
Under the Hood
Retrieve makes use of the internally configured retriever to send a single query or list of multiple queries to determine the top-k relevant passages. The module queries the retriever for each provided query, accumulating scores (or probabilities if the by_prob arg is set) for each passage and returns the passages sorted by their cumulative scores or probabilities.
The Retrieve module can also integrate a reranker if this is configured, in which case, the reranker re-scores the retrieved passages based on their relevance to the quer, improving accuracy of the results.
Tying it All Together
We can now call the Retrieve module on a sample query or list of queries and observe the top-K relevant passages.
query='When was the first FIFA World Cup held?'
# Call the retriever on a particular query.
topK_passages = retriever(query).passages
print(f"Top {retriever.k} passages for question: {query} \n", '-' * 30, '\n')
for idx, passage in enumerate(topK_passages):
print(f'{idx+1}]', passage, '\n')
Top 3 passages for question: When was the first FIFA World Cup held?
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1] History of the FIFA World Cup | The FIFA World Cup was first held in 1930, when FIFA president Jules Rimet [...].
2] 1950 FIFA World Cup | The 1950 FIFA World Cup, held in Brazil from 24 June to 16 July 1950, [...].
3] 1970 FIFA World Cup | The 1970 FIFA World Cup was the ninth FIFA World Cup, the quadrennial [...].