Remove duplicates: full-row vs key-based deduplication

Deduplication isn’t one-size-fits-all. The right method depends on your data quality and what “duplicate” means in your context.

Option 1: Full-row deduplication

Full-row deduplication treats two rows as duplicates only if every column matches.

Use it when:

• You want to remove exact duplicates
• You’re merging exports from the same system
• You trust that identical records truly are duplicates

Downside:

• If one column differs (spacing, casing, timestamp), the rows won’t be considered duplicates.

Option 2: Key-based deduplication

Key-based deduplication dedupes rows using a single column (or key), like:

• email
• customer_id
• order_id

Use it when:

• You know a stable identifier exists
• You’re merging multiple sources
• You want one record per key

Downside:

• If the key is missing or inconsistent, results may be wrong.
• You must decide which row “wins” (first seen is a common strategy).

Best practices

• Trim and normalize key columns before deduping (e.g., email to lowercase).
• Validate how many rows were removed.
• Export and inspect a preview for sanity.

Oriah Sheet supports both modes: full-row comparison or dedup by a selected column key.