Metric Aggregations in Elasticsearch

Introduction

Elasticsearch provides powerful aggregation capabilities that enable you to analyze your data and extract valuable insights. Metric aggregations are a specific type of aggregation focusing on numerical data. They allow you to perform calculations such as averages, sums, and minimum/maximum values on your data.

Types of Metric Aggregations

There are several types of metric aggregations in Elasticsearch:

Avg Aggregation: Calculates the average of numeric values.
Sum Aggregation: Computes the sum of numeric values.
Min Aggregation: Finds the minimum value in numeric fields.
Max Aggregation: Finds the maximum value in numeric fields.
Stats Aggregation: Provides a summary of statistics, including count, min, max, average, and sum.
Extended Stats Aggregation: Offers extended statistics such as variance and standard deviation, in addition to the standard stats.
Value Count Aggregation: Counts the number of values in a dataset.
Percentiles Aggregation: Computes percentiles based on numeric values.
Cardinality Aggregation: Estimates the cardinality (i.e., the count of distinct values).

Examples

Average Aggregation

This example demonstrates how to calculate the average value of a field.

{
    "aggs": {
        "average_price": {
            "avg": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "average_price": {
            "value": 25.0
        }
    }
}

Sum Aggregation

This example shows how to calculate the sum of numeric values in a field.

{
    "aggs": {
        "total_sales": {
            "sum": {
                "field": "sales"
            }
        }
    }
}

{
    "aggregations": {
        "total_sales": {
            "value": 1500.0
        }
    }
}

Min Aggregation

This example demonstrates how to find the minimum value of a field.

{
    "aggs": {
        "min_price": {
            "min": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "min_price": {
            "value": 10.0
        }
    }
}

Max Aggregation

This example shows how to find the maximum value of a field.

{
    "aggs": {
        "max_price": {
            "max": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "max_price": {
            "value": 50.0
        }
    }
}

Stats Aggregation

This example provides a summary of statistics for a numeric field.

{
    "aggs": {
        "price_stats": {
            "stats": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "price_stats": {
            "count": 10,
            "min": 10.0,
            "max": 50.0,
            "avg": 25.0,
            "sum": 250.0
        }
    }
}

Extended Stats Aggregation

This example offers extended statistics for a numeric field.

{
    "aggs": {
        "price_extended_stats": {
            "extended_stats": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "price_extended_stats": {
            "count": 10,
            "min": 10.0,
            "max": 50.0,
            "avg": 25.0,
            "sum": 250.0,
            "sum_of_squares": 12500.0,
            "variance": 200.0,
            "std_deviation": 14.142135623730951
        }
    }
}

Value Count Aggregation

This example counts the number of values in a field.

{
    "aggs": {
        "value_count": {
            "value_count": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "value_count": {
            "value": 10
        }
    }
}

Percentiles Aggregation

This example computes percentiles for numeric values in a field.

{
    "aggs": {
        "price_percentiles": {
            "percentiles": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "price_percentiles": {
            "values": {
                "1.0": 12.0,
                "5.0": 15.0,
                "25.0": 20.0,
                "50.0": 25.0,
                "75.0": 30.0,
                "95.0": 45.0,
                "99.0": 50.0
            }
        }
    }
}

Cardinality Aggregation

This example estimates the cardinality (i.e., the count of distinct values) of a field.

{
    "aggs": {
        "unique_prices": {
            "cardinality": {
                "field": "price"
            }
        }
    }
}

{
    "aggregations": {
        "unique_prices": {
            "value": 7
        }
    }
}