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BM25

The BM25 scoring function uses the Best Matching 25 (BM25) algorithm to sort documents based on their relevance.

Syntax​

BM25(doc, k, b) → score

doc (document): Specified by FOR ... IN viewName k (number, optional): Adjusts the text term frequency scaling. Defaults to 1.2. b (number, optional): Determines the scaling by the total text length. Defaults to 0.75.

Examples​

The following example returns documents sorted by relevance using the BM25 scoring function with default settings:

FOR doc IN viewName
  SEARCH ...
  SORT BM25(doc) DESC
  RETURN doc

This example demonstrates sorting by relevance with a double-weighted term frequency and full text length normalization:

FOR doc IN viewName
  SEARCH ...
  SORT BM25(doc, 2.4, 1) DESC
  RETURN doc