WINDOW_MIN: from Tableau to SQL

Calculates min over all regional marks, excluding null revenues. Below, 8 sample rows go through the calculation and through the SQL, and both return the same numbers.

Calculated field

WINDOW_MIN(SUM([Revenue]))

Compute using: addressing Period; partitioning Region

Sample data

RegionPeriodRevenueCost
Harbor112070
Harbor2180100
Harbor3180120
Harbor4240140
Upland19050
Upland2150110
Upland3null90
Upland4330190

The same calculation as SQL

SELECT CAST((min("Revenue") OVER (PARTITION BY "Region" ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"

Runs the example above.

Result

RegionPeriodRevenueCostresult
Harbor112070120
Harbor2180100120
Harbor3180120120
Harbor4240140120
Upland1905090
Upland215011090
Upland3null9090
Upland433019090

Same rows from the calculation and from the SQL in DuckDB.

Where a naive translation goes wrong

  • Omitting the region partition allows a calculation to consume marks from other regions.

    Naive SQL

    SELECT CAST((min("Revenue") OVER ( ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"
    RegionPeriodRevenueCostresult
    Harbor11207090
    Harbor218010090
    Harbor318012090
    Harbor424014090
    Upland1905090
    Upland215011090
    Upland3null9090
    Upland433019090

    Matches the calculation

    SELECT CAST((min("Revenue") OVER (PARTITION BY "Region" ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"
    RegionPeriodRevenueCostresult
    Harbor112070120
    Harbor2180100120
    Harbor3180120120
    Harbor4240140120
    Upland1905090
    Upland215011090
    Upland3null9090
    Upland433019090

Signature

WINDOW_MIN(expression, [start, end])