Question 329 of 509
Mining and Acquiring DataeasyMultiple ChoiceObjective-mapped

Quick Answer

The correct answer is to check for data freshness. This is because the query `SELECT current_timestamp;` retrieves the exact current date and time from the PostgreSQL server, providing a precise reference point. By comparing this server-generated timestamp against the timestamp of the most recent record in a target table, an analyst can immediately determine whether the data is up-to-date or stale, a critical step before any data acquisition. On the CompTIA Data+ DA0-001 exam, this concept tests your understanding of data quality validation and the practical use of SQL system functions. A common trap is confusing this with a query that actually retrieves data from a table; remember, `current_timestamp` returns the server’s clock, not stored data. For a memory tip, think of it as a “freshness check” — you’re asking the database “what time is it right now?” so you can compare that to “when was the last update?”.

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.

Network Topology
+Refer to the exhibit.```SELECT table_name, num_rows, last_analyzedFROM information_schema.tablesWHERE table_schema = 'public'table_name | num_rows | last_analyzedcustomers | 15234 | 2024-06-01orders | 89732 | 2024-05-30products | 456 | 2024-06-02

Refer to the exhibit. An analyst runs this query before acquiring data from a PostgreSQL database. What is the primary purpose of this query?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "primary"

    Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.

Question 1easymultiple choice
Full question →
Network Topology
+Refer to the exhibit.```SELECT table_name, num_rows, last_analyzedFROM information_schema.tablesWHERE table_schema = 'public'table_name | num_rows | last_analyzedcustomers | 15234 | 2024-06-01orders | 89732 | 2024-05-30products | 456 | 2024-06-02

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

To check for data freshness

The query `SELECT current_timestamp;` returns the current date and time from the PostgreSQL server. By comparing this value with the timestamp of the most recent record in a target table, an analyst can determine if the data is up-to-date or stale. This is a standard technique to check data freshness before proceeding with data acquisition.

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.

  • To verify data types

    Why it's wrong here

    Data types are not shown in this output.

  • To check for data freshness

    Why this is correct

    The 'last_analyzed' column shows when statistics were last updated, indicating freshness.

    Clue confirmation

    The clue word "primary" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

  • To find primary keys

    Why it's wrong here

    The query does not include primary key information.

  • To identify duplicate tables

    Why it's wrong here

    The query lists all tables in public schema, not duplicates.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may confuse `current_timestamp` with a function used for data type verification or schema inspection, when in fact it is solely a temporal function used to gauge data freshness.

Trap categories for this question

  • Command / output trap

    Data types are not shown in this output.

Detailed technical explanation

How to think about this question

The `current_timestamp` function in PostgreSQL returns the transaction's start time with time zone, which is consistent within a single transaction. In real-world ETL pipelines, analysts often compare this value against a `last_updated` column in the source table to decide whether to pull incremental data or a full refresh, avoiding unnecessary data transfer.

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.

Related practice questions

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Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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FAQ

Questions learners often ask

What does this DA0-001 question test?

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: To check for data freshness — The query `SELECT current_timestamp;` returns the current date and time from the PostgreSQL server. By comparing this value with the timestamp of the most recent record in a target table, an analyst can determine if the data is up-to-date or stale. This is a standard technique to check data freshness before proceeding with data acquisition.

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.

Are there clue words in this question I should notice?

Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 24, 2026

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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.