Question 30 of 982

Identify considerations for relational data on Azure →hardMultiple ChoiceObjective-mapped

Quick Answer

The answer is to create a nonclustered index on (OrderDate, CustomerID). This strategy most improves performance because it directly supports both the filter and the sort operations: the index’s leading key, OrderDate, enables a precise index seek for the WHERE clause, while the secondary key, CustomerID, provides the data already sorted, eliminating the need for a separate, costly sort step. On the Microsoft Azure Data Fundamentals DP-900 exam, this scenario tests your understanding of covering indexes and index key order—a common trap is choosing a single-column index on OrderDate alone, which would still require sorting by CustomerID. Remember the memory tip: “Filter first, then order; put the filter column first in your index key.”

DP-900 Practice Question: Identify considerations for relational data on Azure

This DP-900 practice question tests your understanding of identify considerations for relational data on azure. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.

A database administrator manages an Azure SQL Database with a table that has a clustered index on OrderID. Frequent queries filter on OrderDate and then sort the results by CustomerID. These queries perform poorly. Which indexing strategy will most improve performance for these specific queries?

Question 1hardmultiple choice

Full question →

A
Create a nonclustered index on (OrderDate, CustomerID)
This covers both the filter (OrderDate) and the sort order (CustomerID), enabling index seek and avoiding a sort operation.
B
Create a nonclustered index on (CustomerID, OrderDate)
Why wrong: The leading column (CustomerID) does not help filter by OrderDate, so the query cannot perform a seek on OrderDate; it would scan or require sorting.
C
Change the clustered index to (OrderDate)
Why wrong: Altering the clustered index could slow down inserts and queries that rely on OrderID; indexing strategy should not negatively impact primary key lookups.
D
Create a filtered index on OrderDate WHERE CustomerID IS NOT NULL
Why wrong: A filtered index is useful for specific subsets, but it still does not provide the sort order needed and may not be used if many queries do not include the filter predicate.

Full breakdown with real-world 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

✓

Create a nonclustered index on (OrderDate, CustomerID)

The query filters on OrderDate and then sorts by CustomerID. A nonclustered index on (OrderDate, CustomerID) supports both the WHERE clause (by OrderDate) and the ORDER BY clause (by CustomerID) as a covering index, allowing the database engine to perform a single index seek or scan without needing a separate sort operation. This directly addresses the performance bottleneck by eliminating the need to sort the results after filtering.

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.

✓
Create a nonclustered index on (OrderDate, CustomerID)
Why this is correct
This covers both the filter (OrderDate) and the sort order (CustomerID), enabling index seek and avoiding a sort operation.
Related concept
Read the scenario before looking for a memorised answer.
✗
Create a nonclustered index on (CustomerID, OrderDate)
Why it's wrong here
The leading column (CustomerID) does not help filter by OrderDate, so the query cannot perform a seek on OrderDate; it would scan or require sorting.
✗
Change the clustered index to (OrderDate)
Why it's wrong here
Altering the clustered index could slow down inserts and queries that rely on OrderID; indexing strategy should not negatively impact primary key lookups.
✗
Create a filtered index on OrderDate WHERE CustomerID IS NOT NULL
Why it's wrong here
A filtered index is useful for specific subsets, but it still does not provide the sort order needed and may not be used if many queries do not include the filter predicate.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often think a filtered index or changing the clustered index is the best solution, but they overlook that the query requires both filtering and sorting on different columns, and the leading key in a composite index must match the filter column to support both operations efficiently.

Detailed technical explanation

How to think about this question

In SQL Server, a nonclustered index with key columns (OrderDate, CustomerID) creates a B-tree structure where rows are ordered first by OrderDate and then by CustomerID. When the query filters on OrderDate (e.g., WHERE OrderDate = '2023-01-01'), the engine can seek to the exact range in the index, and because the index is already sorted by CustomerID within that range, the ORDER BY CustomerID is satisfied without an additional sort operator in the execution plan. This is a classic covering index scenario that avoids a costly sort operation, which is especially beneficial for large result sets.

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 cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.

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 DP-900 practice-question pages

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

Describe core data concepts practice questions

Practise DP-900 questions linked to Describe core data concepts.

Describe an analytics workload on Azure practice questions

Practise DP-900 questions linked to Describe an analytics workload on Azure.

Identify considerations for relational data on Azure practice questions

Practise DP-900 questions linked to Identify considerations for relational data on Azure.

Describe considerations for working with non-relational data on Azure practice questions

Practise DP-900 questions linked to Describe considerations for working with non-relational data on Azure.

DP-900 fundamentals practice questions

Practise DP-900 questions linked to DP-900 fundamentals.

DP-900 scenario practice questions

Practise DP-900 questions linked to DP-900 scenario.

DP-900 troubleshooting practice questions

Practise DP-900 questions linked to DP-900 troubleshooting.

Practice this exam

Start a free DP-900 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

DP-900 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this DP-900 question test?

Identify considerations for relational data on Azure — This question tests Identify considerations for relational data on Azure — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Create a nonclustered index on (OrderDate, CustomerID) — The query filters on OrderDate and then sorts by CustomerID. A nonclustered index on (OrderDate, CustomerID) supports both the WHERE clause (by OrderDate) and the ORDER BY clause (by CustomerID) as a covering index, allowing the database engine to perform a single index seek or scan without needing a separate sort operation. This directly addresses the performance bottleneck by eliminating the need to sort the results after filtering.

What should I do if I get this DP-900 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Keep practising

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

This DP-900 practice question is part of Courseiva's free Microsoft 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 DP-900 exam.