data-dwh-dbt-project/macros/tests/kpis_daily_outlier_detector.sql

{% test kpis_daily_outlier_detector(
    model, date_column, column_name, sigma_threshold=3, days_to_consider=14
) %}
    with
        -- Retrieve recent data based on the defined days_to_consider
        recent_data as (
            select {{ date_column }}, sum({{ column_name }}) as {{ column_name }}
            from {{ model }}
            where
                {{ date_column }} between (
                    current_date - interval '{{ days_to_consider + 1 }} days'
                ) and (current_date - interval '1 day')
            group by {{ date_column }}
        ),
        metrics_stats as (
            select
                avg({{ column_name }}) as avg_value,
                stddev({{ column_name }}) as stddev_value
            from recent_data
        ),
        outliers as (
            select
                {{ column_name }} as value,
                (abs({{ column_name }} - metrics_stats.avg_value))
                / (metrics_stats.stddev_value) as absolute_deviation_z_score,
                (abs({{ column_name }} - metrics_stats.avg_value))
                / (metrics_stats.stddev_value)
                > {{ sigma_threshold }} as is_outlier
            from {{ model }}
            cross join metrics_stats
            where {{ date_column }} = current_date - interval '1 day'
        )
    -- Return failing rows if any values are flagged as outliers
    select *
    from outliers
    where is_outlier = true
{% endtest %}