Table of Contents

Aggregations

Aggregations compute summary statistics over the documents matching a query, in one pass alongside the search.

Stats and histograms

using Rowles.LeanLucene.Search.Aggregations;

var aggs = new[]
{
    new AggregationRequest("price_stats", "price"),
    new AggregationRequest("price_hist",  "price", AggregationType.Histogram)
    {
        HistogramInterval = 10.0
    },
};

var (hits, results) = searcher.SearchWithAggregations(query, topN: 20, aggs);

foreach (var r in results)
    Console.WriteLine($"{r.Name}: count={r.Count} avg={r.Avg} min={r.Min} max={r.Max}");

Available types

  • AggregationType.Stats — Count, Min, Max, Sum, Avg.
  • AggregationType.Histogram — fixed-width buckets controlled by HistogramInterval (default 10.0).

Histogram results expose the buckets through AggregationResult.Buckets.

Field requirements

The Field must be a numeric doc-values field (i.e., a NumericField).

See also

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