/mozdata:ask How do I query Firefox Desktop DAU?
/mozdata:ask Find probes related to accessibility in Firefox
/mozdata:ask Write a query for the a11y_hcm_foreground metric

/mozdata:ask What tables contain Firefox Desktop telemetry?

> /mozdata:ask how to find most common device that Fenix runs on in Japan?

⏺ I'll help you find the most common device that Fenix (Firefox Android) runs on in Japan. Let me start by exploring what device-related metrics are available
  and identifying the best approach.

⏺ dataHub - search (MCP)(query: "fenix baseline", filters: "{\"and\": [{\"entity_type\": [\"dataset\"]}, {\"platform\": [\"bigquery\"]}]}", num_results: 5)
  ⎿  {
       "count": 5,
       "total": 195,
     … +374 lines (ctrl+o to expand)

⏺ dataHub - get_entity (MCP)(urn: "urn:li:dataset:(urn:li:dataPlatform:bigquery,mozdata.fenix.baseline_clients_daily,PROD)")
  ⎿  {
       "urn": "urn:li:dataset:(urn:li:dataPlatform:bigquery,mozdata.fenix.baseline_clients_daily,PROD)",
       "url": "https://mozilla.acryl.io/dataset/urn%3Ali%3Adataset%3A%28urn%3Ali%3AdataPlatform%3Abigquery%2Cmozdata.fenix.baseline_clients_daily%2CPROD%29/",
     … +437 lines (ctrl+o to expand)

⏺ Perfect! I found the optimal table and device-related fields. Here's how to find the most common devices that Fenix runs on in Japan:

  Answer

  Best table to use: mozdata.fenix.baseline_clients_daily

  This table contains device information at the client-day level and includes:
  - device_manufacturer - The device manufacturer (e.g., Samsung, Google, Xiaomi)
  - device_model - The specific device model (e.g., SM-G991B, Pixel 6)
  - country - Country code for geo-filtering (use 'JP' for Japan)

  Optimized BigQuery Query

  Here's a query to find the most common devices in Japan:

  -- Find most common device models for Fenix in Japan
  -- Uses baseline_clients_daily (client-day level aggregation)
  -- COST: ~$0.10, SPEED: ~2-3 seconds
  SELECT
    device_manufacturer,
    device_model,
    COUNT(DISTINCT client_id) AS unique_clients,
    COUNT(*) AS client_days,
    ROUND(COUNT(DISTINCT client_id) * 100.0 / SUM(COUNT(DISTINCT client_id)) OVER (), 2) AS pct_of_clients
  FROM
    mozdata.fenix.baseline_clients_daily
  WHERE
    submission_date >= DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY)
    AND country = 'JP'  -- Japan
    AND device_model IS NOT NULL
  GROUP BY
    device_manufacturer, device_model
  ORDER BY
    unique_clients DESC
  LIMIT 20

  Query Explanation

  Why this table?
  - baseline_clients_daily is pre-aggregated at the client-day level (one row per client per day)
  - Much faster than querying raw baseline pings (~100x faster)
  - Contains all device metadata we need

  What it does:
  - Counts unique clients per device model/manufacturer combination
  - Filters to Japan (country = 'JP')
  - Shows percentage of total clients for each device
  - Limited to last 7 days (adjust INTERVAL 7 DAY as needed)

  Key fields:
  - unique_clients - Number of distinct users on each device
  - client_days - Total client-days of activity (accounts for multi-day usage)
  - pct_of_clients - Percentage share of each device

  Alternative: By Manufacturer Only

  If you want just the top manufacturers (not specific models):

  -- Top device manufacturers in Japan
  SELECT
    device_manufacturer,
    COUNT(DISTINCT client_id) AS unique_clients,
    ROUND(COUNT(DISTINCT client_id) * 100.0 / SUM(COUNT(DISTINCT client_id)) OVER (), 2) AS pct_of_clients
  FROM
    mozdata.fenix.baseline_clients_daily
  WHERE
    submission_date >= DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY)
    AND country = 'JP'
    AND device_manufacturer IS NOT NULL
  GROUP BY
    device_manufacturer
  ORDER BY
    unique_clients DESC

  Notes

  - Fenix includes all Firefox Android channels (release, beta, nightly)
  - Device data comes from Android system info at the client level
  - Adjust the date range by changing INTERVAL 7 DAY to your preferred window
  - Use sample_id = 0 if you want to test with 1% sample first