The correct choice is incremental extraction using Change Data Capture (CDC) because it reads only the changed rows—inserts, updates, and deletes—directly from transaction logs or change tables, avoiding heavy SELECT queries that would degrade a slow legacy database during business hours. This approach directly addresses the challenge of minimizing impact on legacy database during ETL extraction by eliminating full table scans and frequent query loads, preserving operational performance. On the CompTIA Data+ DA0-001 exam, this tests your understanding of extraction strategies under performance constraints; a common trap is selecting full or incremental extraction with timestamps, which still requires querying the source. Remember the memory tip: CDC means “Capture Delta, not Data dump”—focus on what changed, not everything.
DA0-001 Mining and Acquiring Data Practice Question
This DA0-001 practice question tests your understanding of mining and acquiring data. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A data engineer is designing an ETL pipeline to extract sales data from a legacy on-premise database and load it into a cloud data warehouse. The database is slow and queries during business hours affect performance. Which extraction strategy minimizes impact?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Incremental extraction using Change Data Capture (CDC)
Incremental extraction using Change Data Capture (CDC) minimizes impact on the legacy on-premise database by reading only the changed rows (inserts, updates, deletes) from transaction logs or change tables, rather than issuing heavy SELECT queries. This avoids full table scans or frequent queries during business hours, preserving database performance for operational workloads.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Query the database with SELECT * every hour
Why it's wrong here
Frequent full queries overload the database and worsen performance impact.
✓
Incremental extraction using Change Data Capture (CDC)
Why this is correct
CDC minimizes database load by extracting only changed data, reducing performance impact.
Related concept
Read the scenario before looking for a memorised answer.
✗
Full table extraction nightly
Why it's wrong here
Nightly full extraction still consumes significant resources and may not be incremental enough.
✗
Use a database log shipping
Why it's wrong here
Log shipping is for replication, not typically for ETL extraction, and may not be suitable for incremental loading.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse 'log shipping' (a high-availability technique) with 'Change Data Capture' (an extraction method), or assume that any periodic query (like hourly SELECT *) is acceptable without considering the cumulative performance impact on a slow legacy database.
Detailed technical explanation
How to think about this question
CDC works by reading the database transaction log (e.g., Oracle Redo Logs, SQL Server Transaction Log, or MySQL binlog) to capture row-level changes without querying the source tables. This approach reduces load on the source database to near zero, as the log reader runs as a separate process or uses log-mining APIs. In real-world scenarios, CDC is critical for near-real-time replication from legacy systems where even a nightly full load could cause lock contention or I/O spikes.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the DA0-001 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Mining and Acquiring Data — This question tests Mining and Acquiring Data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Incremental extraction using Change Data Capture (CDC) — Incremental extraction using Change Data Capture (CDC) minimizes impact on the legacy on-premise database by reading only the changed rows (inserts, updates, deletes) from transaction logs or change tables, rather than issuing heavy SELECT queries. This avoids full table scans or frequent queries during business hours, preserving database performance for operational workloads.
What should I do if I get this DA0-001 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A data team is designing an ETL process to extract data from an operational database daily. The database experiences heavy write loads during business hours. What is the best practice to minimize impact on operations?
medium
A.Extract directly from the primary database with high priority
B.Run the extraction during peak hours to ensure data freshness
C.Schedule extraction at midnight when load is low
✓ D.Use replication or a read replica to extract data
Why D: Option B (use a read replica) is best because it offloads the extraction from the primary. Option A (extract from primary) impacts performance. Option C (schedule at midnight) still hits primary. Option D (run during peak) increases load.
Last reviewed: Jun 24, 2026
Question Discussion
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This DA0-001 practice question is part of Courseiva's free CompTIA 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 DA0-001 exam.
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