DA0-002 Data Acquisition and Preparation Practice Test 7 — 15 Questions

Question 1

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 2

A retail company's data analytics team needs to acquire point-of-sale (POS) transaction data from 200 stores daily. Each store sends a CSV file via email at the end of the day. The files often arrive late, have inconsistent column names (e.g., "StoreID", "Store_ID", "store_id"), and occasionally contain corrupted rows. The team manually processes these files, leading to frequent errors and delays. The company wants to automate the acquisition process to ensure data is available by 9 AM the next business day with high quality. Which approach best addresses these issues?

Accepted Answer

Create a script to automatically download email attachments, validate and standardize columns, and flag corrupted rows for review. It directly addresses all three issues: automating the retrieval of email attachments (handling late arrivals), standardizing inconsistent column names via a script (e.g., mapping 'StoreID', 'Store_ID', 'store_id' to a canonical schema), and implementing validation logic to flag corrupted rows for manual review. This approach ensures data is processed reliably by 9 AM without manual intervention, meeting the automation and quality requirements.

Answer

Hire a data entry contractor to manually check and re-enter data

Answer

Ask stores to use a standardized web form to enter data directly into a cloud database

Answer

Implement a VPN so stores can connect to the central database and write transactions in real time

Question 3

A healthcare organization collects patient questionnaire data via paper forms at clinics. The forms are scanned and sent to a central office, where staff manually enter data into an electronic system. This process is slow and error-prone. The organization wants to reduce manual entry errors and speed up data availability. Which method should they adopt?

Accepted Answer

Use optical character recognition (OCR) to digitize the forms and automatically populate the database. Optical Character Recognition (OCR) can convert scanned images to text automatically, reducing manual entry errors and speeding up the process. Requiring patients to fill out online forms may not be feasible for all patients, especially those without internet access. Continuing manual entry with double-checking is still slow and labor-intensive. Sending to an external company introduces additional cost and potential privacy concerns.

Answer

Continue manual entry but double-check all entries

Answer

Send forms to an external data processing company

Answer

Require patients to fill out forms online at home

Question 4

A logistics company receives GPS tracking data from fleet vehicles at 1-second intervals via a cellular network. The data is used to optimize routes and monitor driver behavior. Recently, the data acquisition system has been missing updates for some vehicles when they pass through tunnels or remote areas. The data team notices gaps during these periods. The company needs a solution to ensure near-real-time data continuity. What should they do?

Accepted Answer

Implement a store-and-forward mechanism that buffers data on the vehicle's onboard unit and uploads when connectivity resumes. A store-and-forward mechanism buffers GPS data locally on the vehicle's onboard unit during connectivity loss (e.g., in tunnels) and automatically uploads the backlog when cellular connectivity resumes. This ensures data continuity without requiring real-time transmission, directly addressing the intermittent connectivity issue while maintaining near-real-time updates.

Answer

Use a hybrid approach that combines cellular and Wi-Fi networks

Answer

Increase the frequency of data transmission to every 0.5 seconds

Answer

Switch to a satellite-based GPS system

Question 5

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 6

A financial analytics firm needs to acquire historical stock market tick data (millions of records per day) from a data vendor. The vendor provides data via FTP in binary format. The firm's existing infrastructure uses on-premise servers with limited storage and processing power. They need to stream the data into a cloud data lake for analysis. However, the binary format is proprietary and requires a licensed decoder. The budget is constrained. Which approach best meets the data acquisition requirements?

Accepted Answer

Purchase a license for the decoder and set up an ETL job to convert and upload. Purchasing the decoder license and setting up an ETL job to convert and upload to the cloud directly addresses the format issue and enables streaming to the data lake. Requesting CSV via email is impractical for millions of records. Negotiating for a JSON API is a good idea but may not be available or cost more than the decoder. Using a third-party service adds recurring costs and may introduce dependency.

Answer

Negotiate with the vendor to provide an API that outputs JSON

Answer

Request the vendor to send data in CSV format via email

Answer

Use a third-party cloud service that already decodes and normalizes the data for a subscription fee

Question 7

A social media monitoring company collects public tweets using the Twitter API. The API has a tiered access: free tier allows 500,000 tweets per month, and paid tier allows 2 million tweets per month. The company needs to collect 1.5 million tweets per month for analysis. They are on a free tier but have been exceeding the limit, causing account suspension. They need a sustainable solution without significantly increasing costs. What should they do?

Accepted Answer

Use multiple developer accounts to stay within free limits. Using multiple developer accounts to distribute the collection load can allow access to more tweets while staying within each account's free limit. This avoids the cost of upgrading to a paid tier. Reducing collection to 500,000 tweets would cause loss of critical data. Requesting an academic exemption is unlikely because the company is commercial. Upgrading to paid tier increases costs significantly.

Answer

Request an academic research exemption

Answer

Reduce the collection to exactly 500,000 tweets per month by sampling

Answer

Upgrade to the paid tier

Question 8

A data analyst is performing data acquisition from multiple source files. Which TWO data profiling tasks should the analyst complete before loading the data into the target system?

Accepted Answer

Verify data types and formats. Identifying missing values and verifying data types are fundamental data profiling tasks that help ensure data quality before acquisition. Building models, creating dashboards, or clustering are not part of profiling.

Answer

Create a dashboard for stakeholders

Answer

Build a linear regression model

Answer

Perform cluster analysis

Question 9

Refer to the exhibit. A data analyst is trying to extract data from a SQL Server database but receives the error. Which configuration change should the analyst recommend to the database administrator?

Accepted Answer

Enable Mixed Mode authentication on the SQL Server. The error indicates that the server is configured for Windows authentication only, but the login attempt used SQL authentication. Enabling Mixed Mode authentication allows both Windows and SQL authentication, resolving the issue.

Answer

Change the server firewall to allow port 1433

Answer

Use a different extraction tool that supports Windows authentication

Answer

Grant the 'dataminer' user SELECT permissions

Question 10

A large retail company is integrating customer data from two separate CRM systems into a new data warehouse. System A stores customer IDs as integers (e.g., 12345), while System B stores them as alphanumeric strings (e.g., 'CUST-12345-X'). Additionally, some customers exist in both systems but with slight name variations (e.g., 'John Smith' vs 'Jon Smith'). The data warehouse requires a unified customer table with a single unique identifier for each customer. The analyst needs to design the data acquisition process. Which of the following is the most appropriate first step?

Accepted Answer

Perform data profiling to analyze data distributions, data types, and quality issues in each source. Data profiling is the foundational first step in any data integration project. It systematically assesses source data types, formats, completeness, and quality issues (e.g., integer vs. alphanumeric IDs, name variations) before designing transformation logic. Without profiling, subsequent steps like fuzzy matching or ID standardization risk being built on incorrect assumptions about the data.

Answer

Use a simple crosswalk table based on exact name matches to link records

Answer

Load all data from both systems into a staging table, then run a fuzzy matching algorithm to identify duplicates

Answer

Standardize all customer IDs to a common format (e.g., UUIDs) and then merge the tables

Question 11

A data analyst needs to retrieve all unique job titles from an employees table. Which SQL keyword should be used in the SELECT clause?

Accepted Answer

DISTINCT. DISTINCT removes duplicate rows from the result set, returning only unique values. In this case, SELECT DISTINCT job_title would return each job title only once.

Answer

UNIQUE

Answer

REMOVE DUPLICATES

Answer

FILTER

Question 12

A data analyst is profiling a new dataset containing customer information. When assessing data quality, which metric would be most appropriate to determine if the 'email' column contains valid email addresses?

Accepted Answer

Pattern analysis. Pattern analysis (e.g., using regular expressions) can validate whether strings match the expected format of an email address. Row counts, null counts, and cardinality do not validate format.

Answer

Null count

Answer

Cardinality

Answer

Row count

Question 13

A data analyst is working with a sales table that contains columns: sale_id, product_id, sale_date, and amount. They need to calculate a 7-day moving average of sales amount for each product, ordered by sale_date. Which window function syntax should they use?

Accepted Answer

AVG(amount) OVER (PARTITION BY product_id ORDER BY sale_date ROWS BETWEEN 6 PRECEDING AND CURRENT ROW). A moving average requires averaging over a frame of rows. Using AVG() with an ORDER BY in the OVER clause and a frame specification (ROWS BETWEEN 6 PRECEDING AND CURRENT ROW) calculates the 7-day moving average.

Answer

AVG(amount) OVER (PARTITION BY product_id ORDER BY sale_date)

Answer

AVG(amount) OVER (ORDER BY sale_date ROWS BETWEEN 6 PRECEDING AND CURRENT ROW)

Answer

SUM(amount) OVER (PARTITION BY product_id ORDER BY sale_date ROWS BETWEEN 6 PRECEDING AND CURRENT ROW)

Question 14

A data analyst needs to extract the year from a column named 'order_date' in a SQL database. The database supports standard SQL functions. Which function should they use?

Accepted Answer

EXTRACT(YEAR FROM order_date). The EXTRACT function is standard SQL for extracting date parts. EXTRACT(YEAR FROM order_date) returns the year.

Answer

GET_YEAR(order_date)

Answer

YEAR(order_date)

Answer

DATE_PART('year', order_date)

Question 15

A data analyst wants to retrieve the top 5 highest-paid employees from a table named 'employees' that has columns 'employee_id', 'salary', and 'name'. Which SQL query should they use?

Accepted Answer

SELECT name, salary FROM employees ORDER BY salary DESC LIMIT 5;. ORDER BY salary DESC sorts from highest to lowest, and LIMIT 5 restricts to the first 5 rows.

Answer

SELECT TOP 5 name, salary FROM employees ORDER BY salary DESC;

Answer

SELECT name, salary FROM employees ORDER BY salary ASC LIMIT 5;

Answer

SELECT name, salary FROM employees WHERE ROWNUM <= 5 ORDER BY salary DESC;