SNOW-CSA Reporting, SLA and Imports Practice Question
During an import, the source data contains duplicate records that should be ignored (not imported). The target table has a unique key field u_employee_id. Which configuration in the transform map will prevent these duplicates from creating new records?
⚠ Common exam trap
ServiceNow often tests the distinction between 'coalesce' (which prevents duplicate inserts by checking for existing records) and the non-existent 'Reject duplicates' checkbox, leading candidates to select a plausible-sounding but incorrect option.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set the 'Coalesce' field to true on the field mapping for u_employee_id.
Setting the 'Coalesce' field to true on the field mapping for u_employee_id tells the transform map to use that field as the key for deduplication. When coalesce is enabled, the import engine checks if a record with the same value in that field already exists in the target table; if it does, the incoming record is skipped (not imported). This directly prevents duplicate records from being created without requiring custom scripting or additional configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use a script in the 'On Before' transform to check for existing records.
Why it's wrong here
An 'On Before' transform script executes for every source row, allowing for complex data manipulation or conditional skipping before mapping occurs. While it could be scripted to query the target table and set `ignore = true;` for existing records, this is an inefficient and manual approach for preventing new records based on a unique key. The coalesce functionality of a transform map, configured with the target table's unique key field, is the specific, built-in mechanism designed to automatically identify existing records and prevent new ones from being created from duplicate source data. An 'On Before' script would be appropriate for more intricate validation or data normalisation not directly tied to unique key matching.
- ✗
Set the 'Reject duplicates' checkbox on the transform map.
Why it's wrong here
ServiceNow transform maps do not have a 'Reject duplicates' option; this is a distractor.
- ✓
Set the 'Coalesce' field to true on the field mapping for u_employee_id.
Why this is correct
Coalescing on a unique identifier prevents duplicate key imports by matching existing records.
- ✗
Configure a business rule on the target table to reject duplicates.
Why it's wrong here
Business rules operate after the record is created, so they cannot prevent the initial insert; they could roll back but it's inefficient and not intended for this purpose.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SNOW-CSA practice question is part of Courseiva's free ServiceNow certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SNOW-CSA exam.