Terms & Date Histogram Aggregations

Aggregations let you group and analyze search results.

Terms Aggregation

{
  "aggs": {
    "by_status": {
      "terms": { "field": "status.keyword" }
    }
  }
}

Groups by unique status values.

Date Histogram

{
  "aggs": {
    "sales_per_day": {
      "date_histogram": {
        "field": "orderDate",
        "calendar_interval": "day"
      }
    }
  }
}

Buckets sales by day.

Tips

• Use .keyword fields for terms aggregation
• Avoid too many buckets (set size)
• Use min_doc_count: 0 for empty buckets

Common mistake: Running aggregations on analyzed fields slows queries.