← SQL & Data Engineering / 13

medium★ EssentialMeta Snowflake Databricks

How do you find and remove duplicate rows in SQL, including 'fuzzy' near-duplicates?

Dedup is a daily data-engineering task and a common screen. The signal is ROW_NUMBER to keep the right record (not just DISTINCT), defining what 'duplicate' actually means, and handling near-duplicates at scale.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.

Dedup is a daily data-engineering task and a common screen. The signal is ROW_NUMBER to keep the right record (not just DISTINCT), defining what 'duplicate' actually means, and handling near-duplicates at scale.

more free answers with an account · no card

UP NEXT ON YOUR JOURNEY

Next in this trackHow do you query hierarchical data (org charts, category trees) in SQL with a recursive CTE?Next in this trackHow do you pivot rows into columns in SQL (conditional aggregation)?Next in this trackWrite SQL for a cohort retention analysis (what % of users return in week N after signup).

DISCUSSION · 0

No comments yet — be the first to share your approach.