- A
Close the database connection at the end of each invocation.
Why wrong: Closing the connection prevents reuse and incurs overhead on each invocation.
- B
Open a new database connection inside the handler for each invocation.
Why wrong: Opening a connection each time is slow and may exhaust database connections.
- C
Open the database connection outside the handler function and reuse it.
Reusing connections across invocations reduces latency and resource usage.
- D
Use Amazon RDS Proxy to manage the connection pool.
Why wrong: RDS Proxy is beneficial but not strictly necessary for a single function.
Question 1,391 of 1,616
Lambda Database Connection Best Practice
This DVA-C02 practice question tests your understanding of development with aws services. 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 developer is writing a Lambda function that needs to access an Amazon RDS MySQL database. The function will be invoked frequently. What is the BEST practice for managing the database connection?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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
✓
Open the database connection outside the handler function and reuse it.
Option C is correct because opening the database connection outside the Lambda handler (in the global/initialization scope) allows the connection to be reused across multiple invocations within the same execution environment. This avoids the overhead of establishing a new TCP connection and authentication handshake for every invocation, which is critical for a frequently invoked function. AWS Lambda reuses the execution environment for subsequent invocations, so the persistent connection remains open and reduces latency.
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.
- ✗
Close the database connection at the end of each invocation.
Why it's wrong here
Closing the connection prevents reuse and incurs overhead on each invocation.
- ✗
Open a new database connection inside the handler for each invocation.
Why it's wrong here
Opening a connection each time is slow and may exhaust database connections.
- ✓
Open the database connection outside the handler function and reuse it.
Why this is correct
Reusing connections across invocations reduces latency and resource usage.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Use Amazon RDS Proxy to manage the connection pool.
Why it's wrong here
RDS Proxy is beneficial but not strictly necessary for a single function.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often choose Option D (RDS Proxy) because it sounds like a managed solution, but the question asks for the best practice within the Lambda function itself, and reusing the connection outside the handler is the simpler, more direct approach that the exam expects for serverless patterns.
Detailed technical explanation
How to think about this question
Under the hood, Lambda execution environments are frozen between invocations, but global variables (including database connections) persist in memory. The MySQL client library (e.g., mysql2 or PyMySQL) maintains a socket connection that can be reused, avoiding the three-way TCP handshake and MySQL authentication round trips. In a real-world scenario, if the function is part of a high-traffic API, reusing the connection can reduce invocation latency from ~100ms to ~5ms, but developers must handle connection timeouts and idle disconnections by implementing retry logic or using a connection pool library like mysql-connector-python with pooling.
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 company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
Visual reference
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
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.
- →
Development with AWS Services — study guide chapter
Learn the concepts, then practise the questions
- →
Development with AWS Services practice questions
Targeted practice on this topic area only
- →
All DVA-C02 questions
1,616 questions across all exam domains
- →
AWS Certified Developer Associate DVA-C02 study guide
Full concept coverage aligned to exam objectives
- →
DVA-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Development with AWS Services practice questions
Practise DVA-C02 questions linked to Development with AWS Services.
Security practice questions
Practise DVA-C02 questions linked to Security.
Deployment practice questions
Practise DVA-C02 questions linked to Deployment.
Troubleshooting and Optimization practice questions
Practise DVA-C02 questions linked to Troubleshooting and Optimization.
DVA-C02 fundamentals practice questions
Practise DVA-C02 questions linked to DVA-C02 fundamentals.
DVA-C02 scenario practice questions
Practise DVA-C02 questions linked to DVA-C02 scenario.
DVA-C02 troubleshooting practice questions
Practise DVA-C02 questions linked to DVA-C02 troubleshooting.
Practice this exam
Start a free DVA-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Development with AWS Services — This question tests Development with AWS Services — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Open the database connection outside the handler function and reuse it. — Option C is correct because opening the database connection outside the Lambda handler (in the global/initialization scope) allows the connection to be reused across multiple invocations within the same execution environment. This avoids the overhead of establishing a new TCP connection and authentication handshake for every invocation, which is critical for a frequently invoked function. AWS Lambda reuses the execution environment for subsequent invocations, so the persistent connection remains open and reduces latency.
What should I do if I get this DVA-C02 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: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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 →
Keep practising
More DVA-C02 practice questions
- A developer is troubleshooting an AWS Lambda function that is triggered by an S3 event. The function occasionally fails…
- A developer needs to call AWS APIs from application code running on EC2. Which credential source should the AWS SDK use…
- A developer needs to allow an IAM user in a different AWS account to assume a role in the developer's account. The role…
- A developer needs to grant an IAM role in Account B read-only access to objects in an S3 bucket in Account A. The bucket…
- An API Gateway HTTP API should allow access only to users authenticated by an external OIDC provider. Which authorizer t…
- A developer needs to allow an EC2 instance to read from a DynamoDB table. Which is the best practice to grant permission…
Last reviewed: Jul 4, 2026
This DVA-C02 practice question is part of Courseiva's free Amazon Web Services 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 DVA-C02 exam.
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.
Sign in to join the discussion.