WINDOW_MAX: from Tableau to SQL

Calculates max 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_MAX(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((max("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
Harbor112070240
Harbor2180100240
Harbor3180120240
Harbor4240140240
Upland19050330
Upland2150110330
Upland3null90330
Upland4330190330

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((max("Revenue") OVER ( ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"
    RegionPeriodRevenueCostresult
    Harbor112070330
    Harbor2180100330
    Harbor3180120330
    Harbor4240140330
    Upland19050330
    Upland2150110330
    Upland3null90330
    Upland4330190330

    Matches the calculation

    SELECT CAST((max("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
    Harbor112070240
    Harbor2180100240
    Harbor3180120240
    Harbor4240140240
    Upland19050330
    Upland2150110330
    Upland3null90330
    Upland4330190330

Signature

WINDOW_MAX(expression, [start, end])