sfmc // SQLPRODUCTION
Deterministic Deduplication — Latest Record
Keep the most recent row for each logical identity using ROW_NUMBER().
sqldeduprow_numberdata-extension
Trust & provenancePRODUCTION
Evidence tierPRODUCTIONOfficial sources1Other sources0Last verifiedNot recorded
Evidence tier describes my hands-on relationship with the content. Official sources describe platform contracts/documentation. Production observations should not automatically be treated as official limits.
SELECT
SubscriberKey,
EmailAddress,
ModifiedDate
FROM (
SELECT
SubscriberKey,
EmailAddress,
ModifiedDate,
ROW_NUMBER() OVER (
PARTITION BY SubscriberKey
ORDER BY ModifiedDate DESC
) AS rn
FROM [Source_DE]
) x
WHERE rn = 1Always define an explicit deterministic ORDER BY rule.
Choose the partition key from the business identity, not convenience.