DEA-C02 Data Movement Practice Question
During a data loading process using the COPY command, the data engineer notices that the same files are being processed multiple times, leading to duplicate records. Which Snowflake feature is likely being bypassed or misconfigured?
⚠ Common exam trap
Candidates often suggest that Snowflake automatically detects duplicates based on primary keys. However, Snowflake does not enforce uniqueness, so duplicates occur if the 'FORCE' parameter is used.
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
✓
The Load History metadata maintained by the COPY command.
Snowflake's COPY command and Snowpipe both utilize 'load history' metadata to ensure that each unique file is only loaded once into a specific table. This history is maintained for 64 days. If duplicates are appearing, it is often because the files were modified (changing their checksum) or the engineer is using a method that doesn't check the history, such as using a FORCE=TRUE parameter.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The Change Data Capture (CDC) mechanism in the Snowflake Stream.
Why it's wrong here
Streams are used to track changes within Snowflake tables, not to prevent duplicate ingestion from external stages. While they can be part of a pipeline to handle duplicates later, they are not the primary mechanism Snowflake uses to ensure file-level idempotency during the initial COPY INTO operation.
- ✓
The Load History metadata maintained by the COPY command.
Why this is correct
Snowflake keeps a record of every file successfully loaded into a table. The COPY command checks this history by default and skips files that have already been processed. If this is bypassed (e.g., by changing file names or using FORCE=TRUE), the same data will be ingested again, resulting in duplicates.
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The transactional integrity of the Snowflake Virtual Warehouse.
Why it's wrong here
Transactional integrity ensures that a single COPY command either succeeds completely or fails, but it doesn't track history across different command executions. A warehouse will faithfully execute a COPY command even if it results in duplicates, provided the command is syntactically correct and the user has permissions.
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The automatic deduplication feature of the VARIANT data type.
Why it's wrong here
The VARIANT data type is used for storing semi-structured data and does not have an 'automatic deduplication' feature. Deduplication is a logic-level or ingestion-level process, and the storage format itself does not prevent multiple identical JSON objects from being inserted into a table.
About these practice questions
Courseiva writes every DEA-C02 question from scratch — 229 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Snowflake exam blueprint
This DEA-C02 practice question is part of Courseiva's free Snowflake 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 DEA-C02 exam.