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Answer: Use MERGE to conditionally insert or update records.
MERGE is the best choice for this scenario as it allows for conditional operations where existing records can be updated and new records can be inserted based on specific conditions, ensuring that no duplicates are created. This is more efficient and accurate than other methods like CREATE OR REPLACE TABLE or INSERT OVERWRITE, which do not support conditional operations.
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Consider a scenario where you need to update a Delta Lake table with new data from an external source, ensuring that existing records are updated and new records are inserted without causing duplicates. Which SQL command would you use to achieve this, and why is it the best choice for this scenario?
A
Use CREATE OR REPLACE TABLE to replace the entire table with new data.
B
Use INSERT OVERWRITE to selectively overwrite partitions.
C
Use MERGE to conditionally insert or update records.
D
Use COPY INTO to load data from external sources without duplication.
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