Extracting and Appending Missing Months to a Car Sales Report

DA0-002 By islever Editorial Last updated

Use data acquisition methods Identify data tools

Short answer

D Extract the two missing prior-year months of car sales records and append them as new rows to reach a full twelve-month dataset.

Question

A data analyst is creating a report about cars sold within the last twelve months. The current data set only contains information from the last ten months. Which of the following is the most appropriate way to accomplish this task?
  1. Join the records from the last two months of the previous year and append them to the data table.
  2. Parse the records from the last two months of the previous year and append them to the data table.
  3. Merge the records from the last two months of the previous year and append them to the data table.
  4. Extract the records from the last two months of the previous year and append them to the data table. Correct Answer

Key Takeaways

This question tests whether you understand that vertically adding rows of missing records is an extract-and-append operation, not a join or merge, which combine tables horizontally on keys.

When a report requires twelve months of car sales data but the table only holds ten, the analyst must retrieve the two missing prior-year months and add them as new rows. Extracting the missing records and appending them to the data table is the correct data acquisition and transformation approach.

Common mistake: Option A (Join) is the most tempting wrong answer because joining is a familiar term, but a join matches records on shared columns and adds columns side by side, which cannot supply two additional months of rows. Merge (C) has the same flaw, and Parse (B) refers to interpreting text strings, not retrieving data.

Expert Analysis

Why the Answer Is Correct

Option D is correct because the analyst's problem is a completeness gap: the table needs two more months of rows to cover a rolling twelve-month window. "Extract" describes obtaining the required subset of records from the source data for the last two months of the prior year, and "append" describes adding those records vertically as new rows onto the existing table. This preserves the existing schema and produces one continuous twelve-month dataset suitable for the report.

Why the Other Options Are Wrong

Join and merge (A and C) both combine two tables horizontally by matching on a key column, which adds columns rather than additional month rows, and would fail or duplicate data when the same store or car categories appear in both periods. Parse (B) means breaking a text string into structured components, such as splitting a date field; it does not retrieve missing records from a data source, so parsing the prior-year months cannot make them appear in the table.

Community Comment Notes

A learner comment endorsed D, explaining that "Extract means obtaining the required data, while append means adding those records to the existing table," and separately flagged join as combining tables based on matching columns or keys. That reasoning aligns with standard data acquisition terminology, where extracting a needed subset and appending it vertically is the correct operation for extending a time window.

Exam Strategy

Read what operation the scenario needs on the data shape: adding rows from a missing time period means append, while combining columns across matched keys means join or merge. Match the verb to the direction of growth before reading the full option text.

Frequently Asked Questions

Why is a join or merge wrong when I need more months of sales data?

Joins and merges combine tables horizontally on matching keys, adding columns side by side. To add missing months you need more rows, which is what appending does.

What does parse mean, and why does it not help here?

Parse means interpreting or splitting structured text, such as separating a date string into parts. It does not retrieve missing records from a data source.

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Discussion 1 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 1

  1. Amelia233 👍 1 Answered D
    Correct Answer: D. Extract the records from the last two months of the previous year and append them to the data table. ✅ Explanation: The analyst needs to retrieve the missing two months of data and add them to the existing dataset. Extract means obtaining the required data, while append means adding those records to the existing table. A. Join — ❌ Combines tables based on matching columns or keys. B. Parse — ❌ Breaks data into smaller components or interprets its structure. C. Merge — ❌ Combines datasets, typically based on common fields. D. Extract — ✅ Retrieves the required records, which can then be appended to the dataset.

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