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Running Total Over Telecom Usage

MediumSQL · PostgreSQL00:00
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Your question is Running Total Over Telecom Usage. Start with the requirements and the two tables on the right.

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Problem

Rakuten Symphony's network operations teams need a chronological view of completed telecom usage by service region. Write a PostgreSQL query that aggregates usage by region and day, then calculates a running total for each region.

Requirements

  1. Join usage events to Rakuten Symphony network sites to obtain the region.
  2. Include only completed events from February 2025.
  3. Treat NULL usage values as zero when calculating daily and cumulative usage.
  4. Return region, usage date, daily usage in MB, and the regional running total, ordered by region and date.

Schema

network_sites
ColumnTypeDescription
site_idPKINTEGERUnique network site identifier
site_nameVARCHAR(100)Human-readable site name
regionVARCHAR(50)Service region containing the site
usage_events
ColumnTypeDescription
event_idPKINTEGERUnique usage event identifier
site_idINTEGERNetwork site associated with the event
usage_dateDATEDate of recorded usage
usage_mbNUMERIC(12,2)Usage volume in megabytes
event_statusVARCHAR(20)Usage event processing status
Tablesnetwork_sitesusage_events
Your solutionPostgreSQL
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