aggregate_cardinality

The functionaggregate_cardinality(str agg_name, str fieldname) returns the number documents that passed the relevant filtering.

The aggregation result will be stored under the query results objects, under a key named "agg_name".

Input

• agg_name(str) - Specifies the key that will be used to store the aggregation result under the query result.

• fieldname(str) - The name of the field to aggregate. params[fieldname]must be of type keyword or list[keyword].

Example:

def score_function_recommendation( params, doc):
      score = 0.0 
      if match('genres'): 
         aggregate_cardinality ("cardinality_langauges", 'languages')      
         if match('languages'):
             aggregate_cardinality ("count_genres_languages",'names')
         score += rarity_avg('genres')
     return score

In the above example, the query results will include a key name 'aggregations', containing the following sub keys:

• “cardinality_langauges” - the cardinality of the field "languages" over all candidates that passed the filter over genres.

• "cardinality_genres_languages" - the cardinality of the field "languages" over all candidates that passed the filter over genres and languages.