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Heatmap Widget

The Heatmap widget visualizes numeric values as colored cells across two axes. Clusters, gaps and patterns become visible at a glance – without scanning individual rows.

The data source is always a SQL query against the Data Lake. Configuration is multi-step (Type → Data → Mapping → Style) and supports six predefined heatmap types for the most common analysis patterns.

Typical Use Cases

Use Case Heatmap Type
Work hours over the year Calendar
Activity by weekday and time of day Hour × Weekday
Revenue per month across multiple years Month × Year
Order volume per day of month Day × Month
Seasonal patterns by calendar week Week × Weekday
Department × quarter utilization Matrix

Heatmap Types

Type Axes Suitable for
Calendar Day in year Activity, hours or values across one or more years.
Hour × Weekday 0–23 × Mon–Sun Daily rhythms, load peaks, shift patterns.
Day × Month 1–31 × Months Seasonal fluctuations per day in a month.
Month × Year Jan–Dec × Years Multi-year comparisons per month.
Week × Weekday Week 1–53 × Mon–Sun Weekly patterns across the year.
Matrix Arbitrary categories Any X/Y combination (e.g., department × quarter).

Configuration

The configuration dialog runs through four steps:

  1. Type: Selection of one of the six heatmap types. The remaining steps adapt automatically.
  2. Data: SQL query input. For each type, a hint describes the expected result format. A test run shows the returned rows directly.
  3. Mapping: Definition of which columns serve as X-axis, Y-axis and value. Available columns are taken from the test result.
  4. Style: Title, color scheme and value format (number, duration, currency).

Templates

Each heatmap type ships with a SQL template (e.g., "Hours per day" or "Activity by week/weekday") as a starting point for custom queries.

SQL Assistant

A built-in SQL assistant helps formulate queries. A natural-language description of the desired analysis is enough – the assistant proposes a matching SQL statement.

Display

  • Color schemes: Primary (matches the tenant theme), Green → Red (for ratings) or Blue (neutral).
  • Value scale: A color scale on the right edge shows the value range and allows interactive filtering of a sub-range.
  • Tooltip: Hovering a cell reveals the coordinates and the formatted value.

  • Value format:

    • Number: Raw value with thousands separator.
    • Duration: Seconds rendered as HH:MM:SS.
    • Currency: Value formatted with a currency symbol.

Example

An accounting team wants to identify on which weekdays invoices arrive most frequently. A SQL query against the Data Lake groups incoming invoices by hour and weekday. In Hour × Weekday mode it becomes immediately visible that Monday mornings and Friday afternoons show the strongest peaks.

Tips

  • Aggregate in SQL: The heatmap only renders what the SQL query returns. Aggregation (SUM, COUNT, AVG) and grouping belong in the query, not in the widget.
  • Value range: For strongly skewed values, a manual min/max bound can prevent outliers from distorting the scale.
  • Combine with a table: A heatmap shows the pattern, a table next to it shows the underlying records – together they form a complete drill-down.