RAG with User-Defined Functions Based Reranking

Vectara has introduced User-Defined Functions (UDF) based reranking to provide fine-grained control over search results. This feature allows users to specify their own logic for reranking search results based on metadata from retrieved documents. UDF reranking can be used in combination with other rerankers like Maximal Marginal Relevance (MMR) and Multilingual Reranker v1, allowing for chain reranking to achieve better control over the reranking process. The user-defined function can take advantage of various functions and operators supported by the API, including get(), mathematical functions, date and time functions, and if-else expressions.