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Peak Consumption Per Household
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Peak Consumption Per Household

MediumSQL · PostgreSQL

Problem

Given a dataset of smart meter readings on Kraken, write a query to find the peak energy consumption hour for each household over a 30-day period.

Use the supplied 30-day period from 2025-01-01 inclusive through 2025-01-31 exclusive. Include only households with at least one non-null reading in that period. If multiple hours tie, return the earliest hour.

Output

  1. One row per included household, ordered by household_id
  2. Columns: household_id, household_name, peak_hour, and total_consumption_kwh
  3. peak_hour is the hour of day from 0 through 23, and total_consumption_kwh is that household's summed consumption during the peak hour

Schema

households
ColumnTypeDescription
household_idPKINTEGERUnique household identifier
household_nameVARCHAR(100)Display name for the household
smart_meter_readings
ColumnTypeDescription
reading_idPKINTEGERUnique smart meter reading identifier
household_idINTEGERHousehold associated with the reading
reading_atTIMESTAMPTimestamp when the reading was recorded
consumption_kwhNUMERIC(10,2)Energy consumed in kilowatt-hours
Tableshouseholdssmart_meter_readings
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