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Rolling Average Prescription Volumes
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Rolling Average Prescription Volumes

MediumSQL · PostgreSQL

Problem

Business Context

Genentech's commercial analytics team monitors monthly Ocrevus prescription volume across regional territories. The team needs a smoothed trend that reduces the impact of short-term monthly variation.

Task

Write a PostgreSQL query that calculates the rolling three-month average of Ocrevus prescriptions for each matched regional territory from January through April 2025.

Requirements

  1. Join prescription records to their regional territory names.
  2. Aggregate prescription volume by territory and calendar month before applying the window function.
  3. Calculate a rolling average using the current month and up to the two preceding months within each territory.
  4. Round the rolling average to two decimal places and order the output by territory and month.

Schema

regional_territories
ColumnTypeDescription
territory_idPKINTEGERUnique regional territory identifier
territory_nameVARCHAR(50)Name of the regional territory
region_managerVARCHAR(100)Manager assigned to the territory
prescription_volumes
ColumnTypeDescription
prescription_idPKINTEGERUnique prescription volume record identifier
territory_idINTEGERReferenced regional territory identifier
product_nameVARCHAR(100)Product associated with the prescription record
prescription_monthDATEDate representing the prescription month
prescription_volumeINTEGERNumber of prescriptions recorded
Tablesregional_territoriesprescription_volumes
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