DA0-001 Practice Test 21 — 15 Questions

Question 1

An e-commerce company wants to integrate product pricing data from competitor websites to adjust its own prices dynamically. They plan to scrape pricing pages every hour. However, the competitors' websites have anti-scraping measures such as IP blocking and CAPTCHAs. The company's legal team also advises caution regarding terms of service. Which data acquisition strategy is both effective and compliant?

Accepted Answer

Negotiate with competitors to obtain pricing data via API agreements. Negotiating with competitors to obtain pricing data via API agreements is the most compliant approach, as it avoids violating terms of service and ensures reliable data access. Using rotating proxies and automation to bypass anti-scraping measures may be effective but could violate laws or terms of service. Manual recording is too slow and not dynamic. Using a public data aggregator may not provide the specific competitor data needed and could be costly.

Answer

Use a public data aggregator that already provides competitor pricing with permission

Answer

Use a rotating proxy service and human-like browser automation to bypass blocks

Answer

Instruct staff to manually record prices once a week

Question 2

Refer to the exhibit. What data quality issue is indicated?

Accepted Answer

Non-standardized data entry. The error shows that a non-numeric value 'N/A' is present in a numeric column, indicating non-standardized data entry. Duplication, inconsistency, or outliers are not directly shown.

Answer

Data inconsistency

Answer

Outlier

Answer

Data duplication

Question 3

A retail company wants to analyze customer purchase patterns to identify products frequently bought together. Which data mining technique is most appropriate?

Accepted Answer

Association rules. Association rules (market basket analysis) discover co-occurrence relationships. Regression predicts numeric values, clustering groups similar items, classification assigns categories.

Answer

Classification

Answer

Clustering

Answer

Regression

Question 4

A research firm is acquiring data from public government databases via API. The API rate limits at 100 requests per minute. They need to download 10,000 records, but each request returns a maximum of 100 records. What is the most efficient approach to ensure complete acquisition without being blocked?

Accepted Answer

Use a retry logic with exponential backoff and pagination. Pagination with retry logic using exponential backoff allows the firm to send requests in a controlled manner, respecting the rate limit and handling potential failures. Sending all requests in parallel would likely exceed the rate limit and cause blocking. Downloading one record per second is too slow. Requesting a data dump via email is inefficient and may not be supported.

Answer

Request a data dump from the government via email

Answer

Download one record per second

Answer

Send all requests simultaneously in parallel

Question 5

A data analyst is importing a CSV file that contains a mixture of numeric and text fields. What is the most common issue when importing?

Accepted Answer

Data types being incorrectly inferred. Data type inference often fails, causing numbers to be read as text or vice versa. File size limitations, missing headers, and duplicate rows are less common or not specific to mixed types.

Answer

Duplicate rows

Answer

Missing header row

Answer

File size limitation

Question 6

A healthcare organization acquires data from multiple hospitals with different patient record systems. The data includes patient IDs but no common identifier across systems. Which technique should be used to link records?

Accepted Answer

Probabilistic record linkage using name, DOB, and ZIP. Option D (probabilistic linkage) is designed for such situations. Option A (random IDs) loses connections. Option B (merge without dedup) creates duplicates. Option C (manual matching) is not scalable.

Answer

Merge all records without deduplication

Answer

Generate random unique IDs for each system

Answer

Manually match records for all patients

Question 7

A marketing team wants to analyze customer sentiment from social media posts. Which data acquisition method is most appropriate?

Accepted Answer

Web scraping from public social media APIs. Option D is correct because web scraping from public social media APIs allows direct access to public posts for sentiment analysis. Option A is wrong because internal databases do not contain social media data. Option B is wrong because surveys are not real-time from social media. Option C is wrong because physical sensors are unrelated.

Answer

Internal database query

Answer

Physical sensor data

Answer

Survey questionnaire

Question 8

A data analyst is evaluating data quality issues during acquisition. Which TWO issues are most likely to arise from merging data from different sources? (Select exactly 2)

Accepted Answer

Duplicate records. Options B and D are correct because merging data from different sources often results in duplicate records (same entity represented differently) and formatting inconsistencies (date formats, units). Option A is wrong because high storage cost is not a direct data quality issue. Option C is wrong because slow network speed is a performance issue. Option E is wrong because user access permissions are an authorization issue.

Answer

User access permissions

Answer

Slow network speed

Answer

High storage cost

Question 9

Which TWO are valid data acquisition methods? (Select two.)

Accepted Answer

Web scraping. Web scraping and API calls are direct methods to acquire data from external sources. Data profiling and data normalization are data preparation techniques, not acquisition. Data encryption is a security measure.

Answer

Data normalization

Answer

Data encryption

Answer

Data profiling

Question 10

During data acquisition, a data engineer uses a tool to extract data from a source system incrementally based on a timestamp column. Which method is being used?

Accepted Answer

Change data capture (CDC). Change data capture (CDC) captures modifications since the last extraction. Full extraction retrieves all data each time, snapshot extracts a point-in-time copy, and manual is not automated.

Answer

Snapshot extraction

Answer

Full extraction

Answer

Manual extraction

Question 11

A financial analyst is integrating data from multiple stock exchanges. One exchange provides trade timestamps in UTC, another in Eastern Time. The analyst needs accurate time synchronization for time-series analysis. What is the best approach?

Accepted Answer

Convert all timestamps to a single timezone (e.g., UTC) during ETL. Option D (convert to UTC) is the standard. Option A (keep original with offset) adds complexity. Option B (local time) is inconsistent. Option C (ignore) leads to errors.

Answer

Keep original timezones and add a timezone offset column

Answer

Use the local time of the analyst's location

Answer

Ignore timezone differences if analysis is intraday

Question 12

A data analyst needs to combine sales data from multiple regional databases with different schemas. Which process is best?

Accepted Answer

ETL (Extract, Transform, Load). Option B is correct because ETL (Extract, Transform, Load) is designed to extract data from various sources, transform it to a common schema, and load it into a target system. Option A is wrong because data replication copies data without transformation. Option C is wrong because data virtualization provides real-time access without storing. Option D is wrong because data federation also provides virtual integration but is less suited for combining data into a single store.

Answer

Data federation

Answer

Data replication

Answer

Data virtualization

Question 13

Which THREE are best practices for acquiring data via web scraping? (Select exactly 3)

Accepted Answer

Respect robots.txt. Options A, B, and E are correct because best practices include respecting robots.txt (legal and ethical), limiting request rate (avoid overloading servers), and identifying yourself with a user-agent (transparency). Option C is wrong because using multiple IP addresses may be necessary but is not a best practice per se; it can be used to avoid blocking but may violate terms. Option D is wrong because scraping all data without regard to terms is unethical and possibly illegal.

Answer

Use multiple IP addresses

Answer

Scrape all data without regard to terms

Question 14

Which THREE are challenges in acquiring data from external sources? (Select three.)

Accepted Answer

Licensing restrictions. Data format inconsistency occurs when integrating data from different sources. Rate limiting is a common API restriction that limits how much data can be accessed. Licensing restrictions may limit the use or redistribution of acquired data. Data redundancy is an internal data quality issue, not a challenge specific to acquisition. Unauthorized access is a security concern but not a typical acquisition challenge.

Answer

Data redundancy

Answer

Unauthorized access

Question 15

An organization is acquiring data from an external vendor. The vendor provides a flat file with inconsistent delimiters and missing values. Which step should be performed first in data acquisition?

Accepted Answer

Data profiling. Option C is correct because data profiling examines the data to understand its structure, quality, and issues before any cleansing or transformation. Option A is wrong because data cleansing is performed after profiling. Option B is wrong because data integration combines data from multiple sources. Option D is wrong because data transformation occurs after profiling.

Answer

Data integration

Answer

Data transformation

Answer

Data cleansing