DB Olympics

Queries · q242 · Chief Operating Officer · week 2, night 4

Order-level delivery reliability by carrier group and quarter, 2025 (unified source)

“Did Albion Parcel's reliability break down specifically in Q4 while Landfall Freight and Lowlands Express stayed consistently weak all year, when measured in one single consistent query?”

Manager · asked the questionPriya RamanChief Operating Officer. Came from a third-party logistics provider. Wants to know how reliable the delivery promise is that merchants make on Tidewick.
Analyst · planned the reportLena HartmannSkeptical: checks definitions and sanity totals before trusting a trend.
Engineer · wrote the SQLBeaWrites SQL the way the company's BI tool generates it: verbose fully qualified aliases (t0, t1, ...), a subquery per measure joined back on the grain keys, COALESCE everywhere.

Fictional people at a fictional company, each played by a language-model agent. Who they are and what they are told

  1. Priya Raman writes to Lena Hartmann

    The manager, at the start of week 2

    Subject: Carrier picture confirms it — now I want to know what we can actually fix

    Lena,

    This is exactly the clarity I was hoping for — "it's the carriers, not the warehouses" is a much more actionable story than "fulfillment is inconsistent." A few things jumped out, including from what Daniel's and Tomasz's teams posted this week, and I want to chase them down before we draft anything for merchants or carrier partners.

    What surprised me: Albion Parcel going from solid to broken in November and staying broken through December is different from Landfall and Lowlands, which sound like long-term weak performers we've just tolerated. One is a relationship we may need to end; the other looks like it could be an acute problem (capacity, a route, a depot) that might actually be fixable if we understood the trigger. I don't want to lump all three into one "bad carriers" conversation when they may need completely different responses.

    I also noticed Daniel's team's finding that "where's my order" tickets spike in lockstep with late deliveries each November/December — that's a direct line from the carrier problem to support cost and customer satisfaction, and I'd like to be able to say that explicitly in my own numbers rather than borrowing his.

    Questions for this week:

    1. Of the three weak carriers, which ones are tied to specific regions, lanes, or merchants, versus broadly weak everywhere? I want to know if Albion's November collapse was localized (a single hub, country, or set of merchants) or general — that tells us whether this is a "fix one bad link" problem or a "this carrier can't be trusted" problem.
    2. If we could bring our weak carriers up to the standard of our good ones, how much of our delivery unreliability would actually go away? I want a sense of the ceiling — is this 80% of our problem, or just the long tail?
    3. Can you give me a clean, non-censored view of whether we're genuinely behind on restocking from suppliers, or if that was a year-end timing artifact? You flagged this yourself — I'd like it resolved before I mention supplier reliability to anyone.
    4. Is there any sign that the picking discrepancies Tomasz's team flagged (concentrated in apparel/footwear) are contributing to delivery delays or failed promises — e.g., orders stalling or being corrected after the fact — or is that purely a shrinkage/accounting issue with no customer-facing effect? I want to know if it belongs in the same story as delivery reliability or is a separate track entirely.

    If it's a tight week, prioritize #1 and #2 — I want the carrier narrative airtight before I take it anywhere. Returns/restock cycle time can wait one more week if needed.

    Thanks, Priya

  2. Lena Hartmann plans the night

    The analyst · week 2, night 4, request 2 of 3

    Before I write anything, I cross-checked the three night-3 order-level reports against each other by hand, and they don't reconcile: Report 1 says the three weak carriers blend to 66.8% within 5 days; Report 2's Albion baseline/collapse figures imply Albion alone blends to ~80.1%, which would force Landfall+Lowlands down to ~58.8% to match Report 1's total. But Report 3's "all other carriers" (82.0%, 18,088 orders) combined with Report 1's "good eleven" (93.4%, 13,696 orders) and Report 2's Albion (~80.1%, 2,564 orders) overshoots the reported total on its own -- it would require Landfall's own rate to be negative, which is impossible. So at least one of these three reports has an inconsistency (likely a scoping or computation difference across the three separate queries), and I'm not willing to hand Priya a "ceiling" number or a "fix Lowlands' lanes" recommendation until it's resolved -- this is exactly the kind of number I'd expect her or Daniel's/Tomasz's teams to poke at. Tonight (last night) I'm spending all 3 slots getting a single, internally-consistent source of truth in one query each, rather than stitching across reports: (1) one full-year carrier-level breakdown to anchor the ceiling calculation, (2) one carrier-group-by-quarter breakdown (Albion / Landfall / Lowlands / everyone else) to nail down the timing story cleanly, and (3) one Lowlands-by-lane breakdown done the same consistent way, so the lane-reassignment number is trustworthy. I'll reconcile against this week's earlier reports once these are back and flag any remaining discrepancy explicitly in the memo rather than paper over it.

    Order-level delivery reliability by carrier group and quarter, 2025 (unified source)
    Question
    Did Albion Parcel's reliability break down specifically in Q4 while Landfall Freight and Lowlands Express stayed consistently weak all year, when measured in one single consistent query?
    One row per
    carrier_group and calendar quarter of placed_at, 2025
    Columns
    • carrier_group ('Albion Parcel', 'Landfall Freight', 'Lowlands Express', or 'All other carriers')
    • quarter (e.g. 2025-Q1)
    • orders_fully_delivered
    • avg_delivery_days
    • pct_within_5_days
    • share_of_quarter_orders_pct
  3. Bea writes the SQL

    The engineer · 1 dry run on the empty schema, then the submission

    Dry run 1 · STATUS: COMPILES (dry run on the empty schema, no data read)
    WITH q_orders AS (
      SELECT o.id AS order_id, o.tenant_id, o.placed_at
      FROM orders o
      WHERE o.status = 'fulfilled'
        AND o.placed_at >= DATE '2025-01-01'
        AND o.placed_at < DATE '2026-01-01'
    ),
    fulfillment_counts AS (
      SELECT f.order_id, f.tenant_id, COUNT(*) AS fulfillment_count
      FROM fulfillments f
      JOIN q_orders qo ON qo.order_id = f.order_id AND qo.tenant_id = f.tenant_id
      GROUP BY f.order_id, f.tenant_id
    ),
    single_fulfillment AS (
      SELECT fc.order_id, fc.tenant_id
      FROM fulfillment_counts fc
      WHERE fc.fulfillment_count = 1
    ),
    fulfillment_shipment_counts AS (
      SELECT f.id AS fulfillment_id, f.order_id, f.tenant_id, COUNT(s.id) AS shipment_count
      FROM fulfillments f
      JOIN single_fulfillment sf ON sf.order_id = f.order_id AND sf.tenant_id = f.tenant_id
      LEFT JOIN shipments s ON s.fulfillment_id = f.id AND s.tenant_id = f.tenant_id
      GROUP BY f.id, f.order_id, f.tenant_id
    ),
    qualifying_fulfillments AS (
      SELECT fsc.fulfillment_id, fsc.order_id, fsc.tenant_id
      FROM fulfillment_shipment_counts fsc
      WHERE fsc.shipment_count = 1
    ),
    order_shipment AS (
      SELECT qf.order_id, qf.tenant_id, s.carrier, s.delivered_at
      FROM qualifying_fulfillments qf
      JOIN shipments s ON s.fulfillment_id = qf.fulfillment_id AND s.tenant_id = qf.tenant_id
      WHERE s.delivered_at IS NOT NULL
    ),
    order_detail AS (
      SELECT
        qo.order_id,
        qo.tenant_id,
        qo.placed_at,
        os.carrier,
        os.delivered_at,
        EXTRACT(EPOCH FROM (os.delivered_at - qo.placed_at)) / 86400.0 AS delivery_days
      FROM q_orders qo
      JOIN order_shipment os ON os.order_id = qo.order_id AND os.tenant_id = qo.tenant_id
    ),
    order_detail_grouped AS (
      SELECT
        od.order_id,
        od.tenant_id,
        od.placed_at,
        od.delivery_days,
        CASE
          WHEN od.carrier IN ('Albion Parcel', 'Landfall Freight', 'Lowlands Express') THEN od.carrier
          ELSE 'All other carriers'
        END AS carrier_group
      FROM order_detail od
    ),
    with_quarter AS (
      SELECT
        odg.order_id,
        odg.delivery_days,
        odg.carrier_group,
        cd.year_num,
        cd.quarter_num
      FROM order_detail_grouped odg
      JOIN calendar_days cd ON cd.calendar_date = CAST(odg.placed_at AS DATE)
    ),
    quarter_totals AS (
      SELECT year_num, quarter_num, COUNT(*) AS total_orders
      FROM with_quarter
      GROUP BY year_num, quarter_num
    ),
    group_agg AS (
      SELECT
        year_num,
        quarter_num,
        carrier_group,
        COUNT(*) AS orders_fully_delivered,
        AVG(delivery_days) AS avg_delivery_days,
        AVG(CASE WHEN delivery_days <= 5 THEN 1.0 ELSE 0.0 END) * 100 AS pct_within_5_days
      FROM with_quarter
      GROUP BY year_num, quarter_num, carrier_group
    )
    SELECT
      ga.carrier_group AS carrier_group,
      CONCAT(CAST(ga.year_num AS VARCHAR), '-Q', CAST(ga.quarter_num AS VARCHAR)) AS quarter,
      ga.orders_fully_delivered AS orders_fully_delivered,
      ROUND(CAST(ga.avg_delivery_days AS NUMERIC), 2) AS avg_delivery_days,
      ROUND(CAST(ga.pct_within_5_days AS NUMERIC), 1) AS pct_within_5_days,
      ROUND(CAST(ga.orders_fully_delivered * 100.0 / qt.total_orders AS NUMERIC), 1) AS share_of_quarter_orders_pct
    FROM group_agg ga
    JOIN quarter_totals qt ON qt.year_num = ga.year_num AND qt.quarter_num = ga.quarter_num
    ORDER BY
      ga.quarter_num ASC,
      CASE ga.carrier_group
        WHEN 'Albion Parcel' THEN 1
        WHEN 'Landfall Freight' THEN 2
        WHEN 'Lowlands Express' THEN 3
        ELSE 4
      END ASC

    “The query compiles and produces the expected columns at the right grain. Submitting.”

    Submitted · the SQL of the last dry run, unchanged · Submitted to tonight's batch. Your work on this request is done.

    “Submitted. The query computes order-level delivery reliability per carrier group (Albion Parcel, Landfall Freight, Lowlands Express, and "All other carriers" combined) by calendar quarter of placed_at for 2025, using the same scoping rule as the full-year report (fulfilled orders with exactly one fulfillment containing exactly one delivered shipment). It reports order counts, average delivery days, % delivered within 5 days, and each group's share of that quarter's qualifying orders — all in one consistent query, as requested, so the analyst can directly compare Albion Parcel's Q4 pattern against the steadier Landfall Freight/Lowlands Express trends.”

  4. The report comes back overnight

    As Lena Hartmann saw it, from the small dataset the agents worked on

    carrier_group      | quarter | orders_fully_delivered | avg_delivery_days | pct_within_5_days | share_of_quarter_orders_pct
    -------------------+---------+------------------------+-------------------+-------------------+----------------------------
    Albion Parcel      | 2025-Q1 |                    614 |              3.18 |              95.0 |                        13.4
    Landfall Freight   | 2025-Q1 |                    430 |              5.76 |              42.6 |                         9.4
    Lowlands Express   | 2025-Q1 |                    567 |              4.61 |              64.2 |                        12.4
    All other carriers | 2025-Q1 |                   2980 |              3.35 |              91.4 |                        64.9
    Albion Parcel      | 2025-Q2 |                    587 |              3.58 |              88.8 |                        13.1
    Landfall Freight   | 2025-Q2 |                    366 |              6.08 |              38.8 |                         8.2
    Lowlands Express   | 2025-Q2 |                    560 |              5.27 |              54.1 |                        12.5
    All other carriers | 2025-Q2 |                   2957 |              3.51 |              87.6 |                        66.2
    Albion Parcel      | 2025-Q3 |                    612 |              3.40 |              93.1 |                        13.2
    Landfall Freight   | 2025-Q3 |                    408 |              6.24 |              30.6 |                         8.8
    Lowlands Express   | 2025-Q3 |                    547 |              4.82 |              60.1 |                        11.8
    All other carriers | 2025-Q3 |                   3066 |              3.60 |              86.8 |                        66.2
    Albion Parcel      | 2025-Q4 |                    751 |              7.80 |              50.5 |                        11.0
    Landfall Freight   | 2025-Q4 |                    624 |              6.31 |              31.6 |                         9.1
    Lowlands Express   | 2025-Q4 |                    771 |              4.95 |              58.5 |                        11.3
    All other carriers | 2025-Q4 |                   4693 |              3.46 |              88.6 |                        68.6
    (16 rows)
  5. What came of it

    The memo and the queries that followed; links found by title, so inferred

    It builds on:

  6. It becomes benchmark query q242

    Changed only where the benchmark needs the same result on every system

    • determinismtie-breaker: completes the group key (the CASE is injective over the four carrier_group values)
    • numericsdocs/NUMERICS.md: rounding removed; results keep full precision; bare NUMERIC cast that only served the rounding removed
    • numericsdocs/NUMERICS.md: EXTRACT(EPOCH FROM (b - a)) cast to NUMERIC(18,6)
    • made explicita selected t.col gets AS col, its standard name made explicit (29×)
    • placeholderseconds between
    • determinismthe standard leaves the place of NULLs in a sort to the implementation: NULLS LAST ascending, NULLS FIRST descending, as in the reference results (3×)
    The benchmark text, against the submitted SQL
    WITH q_orders AS (  SELECT o.id AS order_id, o.tenant_id, o.placed_at  SELECT o.id AS order_id, o.tenant_id AS tenant_id, o.placed_at AS placed_at  FROM orders o  WHERE o.status = 'fulfilled'    AND o.placed_at >= DATE '2025-01-01'    AND o.placed_at < DATE '2026-01-01'),fulfillment_counts AS (  SELECT f.order_id, f.tenant_id, COUNT(*) AS fulfillment_count  SELECT f.order_id AS order_id, f.tenant_id AS tenant_id, COUNT(*) AS fulfillment_count  FROM fulfillments f  JOIN q_orders qo ON qo.order_id = f.order_id AND qo.tenant_id = f.tenant_id  GROUP BY f.order_id, f.tenant_id),single_fulfillment AS (  SELECT fc.order_id, fc.tenant_id  SELECT fc.order_id AS order_id, fc.tenant_id AS tenant_id  FROM fulfillment_counts fc  WHERE fc.fulfillment_count = 1),fulfillment_shipment_counts AS (  SELECT f.id AS fulfillment_id, f.order_id, f.tenant_id, COUNT(s.id) AS shipment_count  SELECT f.id AS fulfillment_id, f.order_id AS order_id, f.tenant_id AS tenant_id, COUNT(s.id) AS shipment_count  FROM fulfillments f  JOIN single_fulfillment sf ON sf.order_id = f.order_id AND sf.tenant_id = f.tenant_id  LEFT JOIN shipments s ON s.fulfillment_id = f.id AND s.tenant_id = f.tenant_id  GROUP BY f.id, f.order_id, f.tenant_id),qualifying_fulfillments AS (  SELECT fsc.fulfillment_id, fsc.order_id, fsc.tenant_id  SELECT fsc.fulfillment_id AS fulfillment_id, fsc.order_id AS order_id, fsc.tenant_id AS tenant_id  FROM fulfillment_shipment_counts fsc  WHERE fsc.shipment_count = 1),order_shipment AS (  SELECT qf.order_id, qf.tenant_id, s.carrier, s.delivered_at  SELECT qf.order_id AS order_id, qf.tenant_id AS tenant_id, s.carrier AS carrier, s.delivered_at AS delivered_at  FROM qualifying_fulfillments qf  JOIN shipments s ON s.fulfillment_id = qf.fulfillment_id AND s.tenant_id = qf.tenant_id  WHERE s.delivered_at IS NOT NULL),order_detail AS (  SELECT    qo.order_id,    qo.tenant_id,    qo.placed_at,    os.carrier,    os.delivered_at,    EXTRACT(EPOCH FROM (os.delivered_at - qo.placed_at)) / 86400.0 AS delivery_days    qo.order_id AS order_id,    qo.tenant_id AS tenant_id,    qo.placed_at AS placed_at,    os.carrier AS carrier,    os.delivered_at AS delivered_at,    {{seconds_between(qo.placed_at, os.delivered_at)}} / 86400.0 AS delivery_days  FROM q_orders qo  JOIN order_shipment os ON os.order_id = qo.order_id AND os.tenant_id = qo.tenant_id),order_detail_grouped AS (  SELECT    od.order_id,    od.tenant_id,    od.placed_at,    od.delivery_days,    od.order_id AS order_id,    od.tenant_id AS tenant_id,    od.placed_at AS placed_at,    od.delivery_days AS delivery_days,    CASE      WHEN od.carrier IN ('Albion Parcel', 'Landfall Freight', 'Lowlands Express') THEN od.carrier      ELSE 'All other carriers'    END AS carrier_group  FROM order_detail od),with_quarter AS (  SELECT    odg.order_id,    odg.delivery_days,    odg.carrier_group,    cd.year_num,    cd.quarter_num    odg.order_id AS order_id,    odg.delivery_days AS delivery_days,    odg.carrier_group AS carrier_group,    cd.year_num AS year_num,    cd.quarter_num AS quarter_num  FROM order_detail_grouped odg  JOIN calendar_days cd ON cd.calendar_date = CAST(odg.placed_at AS DATE)),quarter_totals AS (  SELECT year_num, quarter_num, COUNT(*) AS total_orders  FROM with_quarter  GROUP BY year_num, quarter_num),group_agg AS (  SELECT    year_num,    quarter_num,    carrier_group,    COUNT(*) AS orders_fully_delivered,    AVG(delivery_days) AS avg_delivery_days,    AVG(CASE WHEN delivery_days <= 5 THEN 1.0 ELSE 0.0 END) * 100 AS pct_within_5_days  FROM with_quarter  GROUP BY year_num, quarter_num, carrier_group)SELECT  ga.carrier_group AS carrier_group,  CONCAT(CAST(ga.year_num AS VARCHAR), '-Q', CAST(ga.quarter_num AS VARCHAR)) AS quarter,  ga.orders_fully_delivered AS orders_fully_delivered,  ROUND(CAST(ga.avg_delivery_days AS NUMERIC), 2) AS avg_delivery_days,  ROUND(CAST(ga.pct_within_5_days AS NUMERIC), 1) AS pct_within_5_days,  ROUND(CAST(ga.orders_fully_delivered * 100.0 / qt.total_orders AS NUMERIC), 1) AS share_of_quarter_orders_pct  ga.avg_delivery_days AS avg_delivery_days,  ga.pct_within_5_days AS pct_within_5_days,  ga.orders_fully_delivered * 100.0 / qt.total_orders AS share_of_quarter_orders_pctFROM group_agg gaJOIN quarter_totals qt ON qt.year_num = ga.year_num AND qt.quarter_num = ga.quarter_numORDER BY  ga.quarter_num ASC,  ga.quarter_num ASC NULLS LAST,  CASE ga.carrier_group    WHEN 'Albion Parcel' THEN 1    WHEN 'Landfall Freight' THEN 2    WHEN 'Lowlands Express' THEN 3    ELSE 4  END ASC  END ASC NULLS LAST,  ga.year_num NULLS LAST
    WITH q_orders AS (
      SELECT o.id AS order_id, o.tenant_id AS tenant_id, o.placed_at AS placed_at
      FROM orders o
      WHERE o.status = 'fulfilled'
        AND o.placed_at >= DATE '2025-01-01'
        AND o.placed_at < DATE '2026-01-01'
    ),
    fulfillment_counts AS (
      SELECT f.order_id AS order_id, f.tenant_id AS tenant_id, COUNT(*) AS fulfillment_count
      FROM fulfillments f
      JOIN q_orders qo ON qo.order_id = f.order_id AND qo.tenant_id = f.tenant_id
      GROUP BY f.order_id, f.tenant_id
    ),
    single_fulfillment AS (
      SELECT fc.order_id AS order_id, fc.tenant_id AS tenant_id
      FROM fulfillment_counts fc
      WHERE fc.fulfillment_count = 1
    ),
    fulfillment_shipment_counts AS (
      SELECT f.id AS fulfillment_id, f.order_id AS order_id, f.tenant_id AS tenant_id, COUNT(s.id) AS shipment_count
      FROM fulfillments f
      JOIN single_fulfillment sf ON sf.order_id = f.order_id AND sf.tenant_id = f.tenant_id
      LEFT JOIN shipments s ON s.fulfillment_id = f.id AND s.tenant_id = f.tenant_id
      GROUP BY f.id, f.order_id, f.tenant_id
    ),
    qualifying_fulfillments AS (
      SELECT fsc.fulfillment_id AS fulfillment_id, fsc.order_id AS order_id, fsc.tenant_id AS tenant_id
      FROM fulfillment_shipment_counts fsc
      WHERE fsc.shipment_count = 1
    ),
    order_shipment AS (
      SELECT qf.order_id AS order_id, qf.tenant_id AS tenant_id, s.carrier AS carrier, s.delivered_at AS delivered_at
      FROM qualifying_fulfillments qf
      JOIN shipments s ON s.fulfillment_id = qf.fulfillment_id AND s.tenant_id = qf.tenant_id
      WHERE s.delivered_at IS NOT NULL
    ),
    order_detail AS (
      SELECT
        qo.order_id AS order_id,
        qo.tenant_id AS tenant_id,
        qo.placed_at AS placed_at,
        os.carrier AS carrier,
        os.delivered_at AS delivered_at,
        CAST(EXTRACT(EPOCH FROM (os.delivered_at - qo.placed_at)) AS NUMERIC(18,6)) / 86400.0 AS delivery_days
      FROM q_orders qo
      JOIN order_shipment os ON os.order_id = qo.order_id AND os.tenant_id = qo.tenant_id
    ),
    order_detail_grouped AS (
      SELECT
        od.order_id AS order_id,
        od.tenant_id AS tenant_id,
        od.placed_at AS placed_at,
        od.delivery_days AS delivery_days,
        CASE
          WHEN od.carrier IN ('Albion Parcel', 'Landfall Freight', 'Lowlands Express') THEN od.carrier
          ELSE 'All other carriers'
        END AS carrier_group
      FROM order_detail od
    ),
    with_quarter AS (
      SELECT
        odg.order_id AS order_id,
        odg.delivery_days AS delivery_days,
        odg.carrier_group AS carrier_group,
        cd.year_num AS year_num,
        cd.quarter_num AS quarter_num
      FROM order_detail_grouped odg
      JOIN calendar_days cd ON cd.calendar_date = CAST(odg.placed_at AS DATE)
    ),
    quarter_totals AS (
      SELECT year_num, quarter_num, COUNT(*) AS total_orders
      FROM with_quarter
      GROUP BY year_num, quarter_num
    ),
    group_agg AS (
      SELECT
        year_num,
        quarter_num,
        carrier_group,
        COUNT(*) AS orders_fully_delivered,
        AVG(delivery_days) AS avg_delivery_days,
        AVG(CASE WHEN delivery_days <= 5 THEN 1.0 ELSE 0.0 END) * 100 AS pct_within_5_days
      FROM with_quarter
      GROUP BY year_num, quarter_num, carrier_group
    )
    SELECT
      ga.carrier_group AS carrier_group,
      CONCAT(CAST(ga.year_num AS VARCHAR), '-Q', CAST(ga.quarter_num AS VARCHAR)) AS quarter,
      ga.orders_fully_delivered AS orders_fully_delivered,
      ga.avg_delivery_days AS avg_delivery_days,
      ga.pct_within_5_days AS pct_within_5_days,
      ga.orders_fully_delivered * 100.0 / qt.total_orders AS share_of_quarter_orders_pct
    FROM group_agg ga
    JOIN quarter_totals qt ON qt.year_num = ga.year_num AND qt.quarter_num = ga.quarter_num
    ORDER BY
      ga.quarter_num ASC NULLS LAST,
      CASE ga.carrier_group
        WHEN 'Albion Parcel' THEN 1
        WHEN 'Landfall Freight' THEN 2
        WHEN 'Lowlands Express' THEN 3
        ELSE 4
      END ASC NULLS LAST,
      ga.year_num NULLS LAST
    100 ms1 s10 sHyper1.11 sDuckDB965 msGizmoSQL705 msclickhouse_brew2.63 sFirebolt1.57 sDataFusion3.45 sClickHouse4.62 s
  7. Everything, as recorded

    The agents' own records, as the role play wrote them; only the personal data of the person who ran it is redacted

    Bea's whole session, 7 turns
    • The request, as Bea received it
      Report request from Lena Hartmann (analyst for the Chief Operating Officer):
      
      Title: Order-level delivery reliability by carrier group and quarter, 2025 (unified source)
      Question: Did Albion Parcel's reliability break down specifically in Q4 while Landfall Freight and Lowlands Express stayed consistently weak all year, when measured in one single consistent query?
      Grain: one row per carrier_group and calendar quarter of placed_at, 2025
      Columns:
      - carrier_group ('Albion Parcel', 'Landfall Freight', 'Lowlands Express', or 'All other carriers')
      - quarter (e.g. 2025-Q1)
      - orders_fully_delivered
      - avg_delivery_days
      - pct_within_5_days
      - share_of_quarter_orders_pct
      Details: Same scoping and single-carrier attribution rule as the full-year carrier report (orders placed_at in 2025, status='fulfilled', exactly one fulfillment with exactly one shipment, delivered_at not null). Group by quarter of orders.placed_at (use calendar_days.quarter_num/quarter_start) and by carrier_group, where carrier_group = the shipment's carrier name if it is 'Albion Parcel', 'Landfall Freight', or 'Lowlands Express', else 'All other carriers' (all remaining carriers summed together). Round avg_delivery_days to 2 decimals, pct columns to 1 decimal. Order by quarter ascending, then carrier_group in this fixed order: Albion Parcel, Landfall Freight, Lowlands Express, All other carriers. Expect 16 rows (4 quarters x 4 groups).
      
      Check your query with the warehouse's dry_run tool, then hand it in with submit.
    • Bea calls dry_run
      WITH q_orders AS (
        SELECT o.id AS order_id, o.tenant_id, o.placed_at
        FROM orders o
        WHERE o.status = 'fulfilled'
          AND o.placed_at >= DATE '2025-01-01'
          AND o.placed_at < DATE '2026-01-01'
      ),
      fulfillment_counts AS (
        SELECT f.order_id, f.tenant_id, COUNT(*) AS fulfillment_count
        FROM fulfillments f
        JOIN q_orders qo ON qo.order_id = f.order_id AND qo.tenant_id = f.tenant_id
        GROUP BY f.order_id, f.tenant_id
      ),
      single_fulfillment AS (
        SELECT fc.order_id, fc.tenant_id
        FROM fulfillment_counts fc
        WHERE fc.fulfillment_count = 1
      ),
      fulfillment_shipment_counts AS (
        SELECT f.id AS fulfillment_id, f.order_id, f.tenant_id, COUNT(s.id) AS shipment_count
        FROM fulfillments f
        JOIN single_fulfillment sf ON sf.order_id = f.order_id AND sf.tenant_id = f.tenant_id
        LEFT JOIN shipments s ON s.fulfillment_id = f.id AND s.tenant_id = f.tenant_id
        GROUP BY f.id, f.order_id, f.tenant_id
      ),
      qualifying_fulfillments AS (
        SELECT fsc.fulfillment_id, fsc.order_id, fsc.tenant_id
        FROM fulfillment_shipment_counts fsc
        WHERE fsc.shipment_count = 1
      ),
      order_shipment AS (
        SELECT qf.order_id, qf.tenant_id, s.carrier, s.delivered_at
        FROM qualifying_fulfillments qf
        JOIN shipments s ON s.fulfillment_id = qf.fulfillment_id AND s.tenant_id = qf.tenant_id
        WHERE s.delivered_at IS NOT NULL
      ),
      order_detail AS (
        SELECT
          qo.order_id,
          qo.tenant_id,
          qo.placed_at,
          os.carrier,
          os.delivered_at,
          EXTRACT(EPOCH FROM (os.delivered_at - qo.placed_at)) / 86400.0 AS delivery_days
        FROM q_orders qo
        JOIN order_shipment os ON os.order_id = qo.order_id AND os.tenant_id = qo.tenant_id
      ),
      order_detail_grouped AS (
        SELECT
          od.order_id,
          od.tenant_id,
          od.placed_at,
          od.delivery_days,
          CASE
            WHEN od.carrier IN ('Albion Parcel', 'Landfall Freight', 'Lowlands Express') THEN od.carrier
            ELSE 'All other carriers'
          END AS carrier_group
        FROM order_detail od
      ),
      with_quarter AS (
        SELECT
          odg.order_id,
          odg.delivery_days,
          odg.carrier_group,
          cd.year_num,
          cd.quarter_num
        FROM order_detail_grouped odg
        JOIN calendar_days cd ON cd.calendar_date = CAST(odg.placed_at AS DATE)
      ),
      quarter_totals AS (
        SELECT year_num, quarter_num, COUNT(*) AS total_orders
        FROM with_quarter
        GROUP BY year_num, quarter_num
      ),
      group_agg AS (
        SELECT
          year_num,
          quarter_num,
          carrier_group,
          COUNT(*) AS orders_fully_delivered,
          AVG(delivery_days) AS avg_delivery_days,
          AVG(CASE WHEN delivery_days <= 5 THEN 1.0 ELSE 0.0 END) * 100 AS pct_within_5_days
        FROM with_quarter
        GROUP BY year_num, quarter_num, carrier_group
      )
      SELECT
        ga.carrier_group AS carrier_group,
        CONCAT(CAST(ga.year_num AS VARCHAR), '-Q', CAST(ga.quarter_num AS VARCHAR)) AS quarter,
        ga.orders_fully_delivered AS orders_fully_delivered,
        ROUND(CAST(ga.avg_delivery_days AS NUMERIC), 2) AS avg_delivery_days,
        ROUND(CAST(ga.pct_within_5_days AS NUMERIC), 1) AS pct_within_5_days,
        ROUND(CAST(ga.orders_fully_delivered * 100.0 / qt.total_orders AS NUMERIC), 1) AS share_of_quarter_orders_pct
      FROM group_agg ga
      JOIN quarter_totals qt ON qt.year_num = ga.year_num AND qt.quarter_num = ga.quarter_num
      ORDER BY
        ga.quarter_num ASC,
        CASE ga.carrier_group
          WHEN 'Albion Parcel' THEN 1
          WHEN 'Landfall Freight' THEN 2
          WHEN 'Lowlands Express' THEN 3
          ELSE 4
        END ASC
    • The warehouse answers
      STATUS: COMPILES (dry run on the empty schema, no data read)
      COLUMNS: carrier_group, quarter, orders_fully_delivered, avg_delivery_days, pct_within_5_days, share_of_quarter_orders_pct
    • BeaThe query compiles and produces the expected columns at the right grain. Submitting.
    • Bea calls submit
      WITH q_orders AS (
        SELECT o.id AS order_id, o.tenant_id, o.placed_at
        FROM orders o
        WHERE o.status = 'fulfilled'
          AND o.placed_at >= DATE '2025-01-01'
          AND o.placed_at < DATE '2026-01-01'
      ),
      fulfillment_counts AS (
        SELECT f.order_id, f.tenant_id, COUNT(*) AS fulfillment_count
        FROM fulfillments f
        JOIN q_orders qo ON qo.order_id = f.order_id AND qo.tenant_id = f.tenant_id
        GROUP BY f.order_id, f.tenant_id
      ),
      single_fulfillment AS (
        SELECT fc.order_id, fc.tenant_id
        FROM fulfillment_counts fc
        WHERE fc.fulfillment_count = 1
      ),
      fulfillment_shipment_counts AS (
        SELECT f.id AS fulfillment_id, f.order_id, f.tenant_id, COUNT(s.id) AS shipment_count
        FROM fulfillments f
        JOIN single_fulfillment sf ON sf.order_id = f.order_id AND sf.tenant_id = f.tenant_id
        LEFT JOIN shipments s ON s.fulfillment_id = f.id AND s.tenant_id = f.tenant_id
        GROUP BY f.id, f.order_id, f.tenant_id
      ),
      qualifying_fulfillments AS (
        SELECT fsc.fulfillment_id, fsc.order_id, fsc.tenant_id
        FROM fulfillment_shipment_counts fsc
        WHERE fsc.shipment_count = 1
      ),
      order_shipment AS (
        SELECT qf.order_id, qf.tenant_id, s.carrier, s.delivered_at
        FROM qualifying_fulfillments qf
        JOIN shipments s ON s.fulfillment_id = qf.fulfillment_id AND s.tenant_id = qf.tenant_id
        WHERE s.delivered_at IS NOT NULL
      ),
      order_detail AS (
        SELECT
          qo.order_id,
          qo.tenant_id,
          qo.placed_at,
          os.carrier,
          os.delivered_at,
          EXTRACT(EPOCH FROM (os.delivered_at - qo.placed_at)) / 86400.0 AS delivery_days
        FROM q_orders qo
        JOIN order_shipment os ON os.order_id = qo.order_id AND os.tenant_id = qo.tenant_id
      ),
      order_detail_grouped AS (
        SELECT
          od.order_id,
          od.tenant_id,
          od.placed_at,
          od.delivery_days,
          CASE
            WHEN od.carrier IN ('Albion Parcel', 'Landfall Freight', 'Lowlands Express') THEN od.carrier
            ELSE 'All other carriers'
          END AS carrier_group
        FROM order_detail od
      ),
      with_quarter AS (
        SELECT
          odg.order_id,
          odg.delivery_days,
          odg.carrier_group,
          cd.year_num,
          cd.quarter_num
        FROM order_detail_grouped odg
        JOIN calendar_days cd ON cd.calendar_date = CAST(odg.placed_at AS DATE)
      ),
      quarter_totals AS (
        SELECT year_num, quarter_num, COUNT(*) AS total_orders
        FROM with_quarter
        GROUP BY year_num, quarter_num
      ),
      group_agg AS (
        SELECT
          year_num,
          quarter_num,
          carrier_group,
          COUNT(*) AS orders_fully_delivered,
          AVG(delivery_days) AS avg_delivery_days,
          AVG(CASE WHEN delivery_days <= 5 THEN 1.0 ELSE 0.0 END) * 100 AS pct_within_5_days
        FROM with_quarter
        GROUP BY year_num, quarter_num, carrier_group
      )
      SELECT
        ga.carrier_group AS carrier_group,
        CONCAT(CAST(ga.year_num AS VARCHAR), '-Q', CAST(ga.quarter_num AS VARCHAR)) AS quarter,
        ga.orders_fully_delivered AS orders_fully_delivered,
        ROUND(CAST(ga.avg_delivery_days AS NUMERIC), 2) AS avg_delivery_days,
        ROUND(CAST(ga.pct_within_5_days AS NUMERIC), 1) AS pct_within_5_days,
        ROUND(CAST(ga.orders_fully_delivered * 100.0 / qt.total_orders AS NUMERIC), 1) AS share_of_quarter_orders_pct
      FROM group_agg ga
      JOIN quarter_totals qt ON qt.year_num = ga.year_num AND qt.quarter_num = ga.quarter_num
      ORDER BY
        ga.quarter_num ASC,
        CASE ga.carrier_group
          WHEN 'Albion Parcel' THEN 1
          WHEN 'Landfall Freight' THEN 2
          WHEN 'Lowlands Express' THEN 3
          ELSE 4
        END ASC
    • The warehouse answers
      Submitted to tonight's batch. Your work on this request is done.
    • BeaSubmitted. The query computes order-level delivery reliability per carrier group (Albion Parcel, Landfall Freight, Lowlands Express, and "All other carriers" combined) by calendar quarter of `placed_at` for 2025, using the same scoping rule as the full-year report (fulfilled orders with exactly one fulfillment containing exactly one delivered shipment). It reports order counts, average delivery days, % delivered within 5 days, and each group's share of that quarter's qualifying orders — all in one consistent query, as requested, so the analyst can directly compare Albion Parcel's Q4 pattern against the steadier Landfall Freight/Lowlands Express trends.