Answer-first summary for fast verification
Answer: Records that violate the expectation are dropped from the target dataset and recorded as invalid in the event log.
## Explanation In Delta Live Tables (DLT), when you define a constraint with `ON VIOLATION DROP ROW`, the behavior is: 1. **Records violating the constraint are dropped** from the target dataset (not loaded into it) 2. **Violations are recorded in the event log** for monitoring and debugging purposes 3. **The job continues processing** (does not fail) Let's break down the options: - **Option A**: Incorrect - DLT does not automatically load dropped rows into a quarantine table. You would need to explicitly create a separate table for that. - **Option B**: Incorrect - This describes `ON VIOLATION FAIL UPDATE` behavior where invalid records are added with a flag. - **Option C**: **CORRECT** - This accurately describes `ON VIOLATION DROP ROW` behavior: dropped from target dataset and recorded in event log. - **Option D**: Incorrect - Records are NOT added to the target dataset with `DROP ROW`. - **Option E**: Incorrect - This would be `ON VIOLATION FAIL UPDATE` behavior, not `DROP ROW`. **Key DLT Constraint Behaviors:** - `ON VIOLATION DROP ROW`: Drop violating rows, record in event log - `ON VIOLATION FAIL UPDATE`: Fail the pipeline if violations exceed threshold - Without `ON VIOLATION` clause: Records are added with metadata about violations This behavior allows data quality monitoring while ensuring only valid data enters the target dataset.
Author: Keng Suppaseth
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A dataset has been defined using Delta Live Tables and includes an expectations clause: CONSTRAINT valid_timestamp EXPECT (timestamp > '2020-01-01') ON VIOLATION DROP ROW What is the expected behavior when a batch of data containing data that violates these constraints is processed?
A
Records that violate the expectation are dropped from the target dataset and loaded into a quarantine table.
B
Records that violate the expectation are added to the target dataset and flagged as invalid in a field added to the target dataset.
C
Records that violate the expectation are dropped from the target dataset and recorded as invalid in the event log.
D
Records that violate the expectation are added to the target dataset and recorded as invalid in the event log.
E
Records that violate the expectation cause the job to fail.