Comparing two result sets

WITH rebuilt AS (
  SELECT
    -- make_sk() verbatim: trim, upper, coalesce to the sentinel, concat_ws,
    -- sha2. Any deviation and EVERY row reports as both missing and extra.
    sha2(concat_ws('||', COALESCE(UPPER(TRIM(customer_id)), '~')), 256)
                                        AS customer_sk,
    customer_id,
    customer_name,
    country,
    customer_segment,
    CAST(_tech_valid_from AS TIMESTAMP) AS _tech_valid_from,
    CAST(_tech_valid_to   AS TIMESTAMP) AS _tech_valid_to
  FROM silver.customer
),
deployed AS (
  SELECT
    customer_sk, customer_id, customer_name, country, customer_segment,
    _tech_valid_from, _tech_valid_to
  FROM gold.dim_customer
)
SELECT 'missing_from_gold' AS side, *
FROM (SELECT * FROM rebuilt  EXCEPT ALL SELECT * FROM deployed)
UNION ALL
SELECT 'extra_in_gold' AS side, *
FROM (SELECT * FROM deployed EXCEPT ALL SELECT * FROM rebuilt)

-- same WITH rebuilt AS (...), deployed AS (...) header as above
SELECT 'extra_in_gold' AS side, d.customer_sk, d._tech_valid_from
FROM deployed d
LEFT JOIN rebuilt r
       ON  r.customer_sk       IS NOT DISTINCT FROM d.customer_sk
       AND r._tech_valid_from  IS NOT DISTINCT FROM d._tech_valid_from
       AND r.customer_segment  IS NOT DISTINCT FROM d.customer_segment
-- customer_sk is a hash and is never NULL, which is the ONLY reason it can
-- serve as the did-it-match sentinel. Pick a nullable column here and the
-- anti-join reports matched rows as missing.
WHERE r.customer_sk IS NULL

UNION ALL

-- The second half is not optional. The half above finds rows gold has and the
-- rebuild does not; alone it is blind to rows the rebuild has and gold lost.
-- Stopping there fixes trap #3 and hands you trap #1 with NULL-safe predicates
-- bolted on — which is worse, because it now looks deliberate.
SELECT 'missing_from_gold' AS side, r.customer_sk, r._tech_valid_from
FROM rebuilt r
LEFT JOIN deployed d
       ON  d.customer_sk       IS NOT DISTINCT FROM r.customer_sk
       AND d._tech_valid_from  IS NOT DISTINCT FROM r._tech_valid_from
       AND d.customer_segment  IS NOT DISTINCT FROM r.customer_segment
WHERE d.customer_sk IS NULL

-- The CTE is mandatory, not stylistic: a metric view cannot be joined by the
-- consuming query, so it is read once here and only the CTE meets the set
-- operator. The casts below are NOT doc-confirmed — verify on the workspace.
WITH from_view AS (
  SELECT
    country,
    CAST(month AS DATE)                      AS month,
    CAST(MEASURE(revenue) AS DECIMAL(18,2))  AS revenue,
    CAST(MEASURE(order_count) AS BIGINT)     AS order_count
  FROM gold.mv_sales
  GROUP BY country, month
),
oracle AS (
  SELECT
    c.country,
    CAST(DATE_TRUNC('MONTH', f.order_ts) AS DATE)  AS month,
    CAST(SUM(f.amount_eur) AS DECIMAL(18,2))       AS revenue,
    CAST(COUNT(DISTINCT f.order_id) AS BIGINT)     AS order_count
  FROM gold.fct_order_line f
  JOIN gold.dim_customer c
    ON  c.customer_sk = f.customer_sk
    -- the view joins the CURRENT version (see the mv_sales YAML), so the
    -- oracle does too. Join on the interval here and the oracle is red for
    -- every customer who ever moved country — a real question, but a
    -- different assertion, not this one.
    AND c._tech_is_current
  WHERE f.status IS DISTINCT FROM 'CANCELLED'
  GROUP BY 1, 2
)
SELECT 'metric_view_only' AS side, *
FROM (SELECT * FROM from_view EXCEPT ALL SELECT * FROM oracle)
UNION ALL
SELECT 'oracle_only' AS side, *
FROM (SELECT * FROM oracle EXCEPT ALL SELECT * FROM from_view)