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Data Concepts and EnvironmentshardMultiple ChoiceObjective-mapped

DA0-002 Data Concepts and Environments Practice Question

A financial services company is migrating its customer data from a legacy on-premises relational database to a cloud-based data warehouse. The legacy database uses a denormalized schema with a single table 'customer_master' that contains all customer attributes, including repeated groups for multiple accounts per customer (account1_type, account1_balance, account2_type, account2_balance, etc.). The data warehouse team wants to implement a normalized star schema with separate dimension and fact tables. During the ETL process, the team encounters an error: 'Data truncation: string data right truncation' when loading account_type values into the dim_account table. The account_type column in dim_account is defined as VARCHAR(10), but the source data contains account types like 'SavingsPlus' (11 characters) and 'CheckingPremium' (15 characters). The team must resolve this issue without losing data. Which course of action should the team take?

⚠ Common exam trap

Many exam-takers choose truncation (Option A) or NULL insertion (Option C) as quick fixes, overlooking the requirement to preserve data integrity, or mistakenly think TEXT (Option B) is a safe catch-all without considering performance implications in a data warehouse context.

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

Increase the VARCHAR length of dim_account.account_type to accommodate the longest account type.

Increasing the VARCHAR length of dim_account.account_type to accommodate the longest account type (e.g., VARCHAR(15) for 'CheckingPremium') resolves the data truncation error without data loss. This aligns with the star schema design principle of preserving source data integrity while ensuring the column definition matches the actual data length. The team must avoid truncation or NULL insertion to maintain accurate dimensional attributes for analytics.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Truncate the account_type values to 10 characters during ETL.

    Why it's wrong here

    Truncation causes data loss.

  • Change the data type of dim_account.account_type to TEXT.

    Why it's wrong here

    TEXT is valid but not optimal; better to increase VARCHAR length.

  • Ignore the error and continue loading with NULL values for truncated rows.

    Why it's wrong here

    Ignoring errors leads to incomplete data.

  • Increase the VARCHAR length of dim_account.account_type to accommodate the longest account type.

    Why this is correct

    This resolves truncation without data loss.

Visual reference

Client Recursive Resolver Root DNS (13 root servers) TLD DNS (.com, .org, …) Authoritative example.com query IP addr answer

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Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This DA0-002 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 DA0-002 exam.