PDII Practice Test Questions

Explanation:

The best approach to handle long-running Apex processes with sequential database operations and web service callouts is to use Queueable Apex. This method allows you to break down complex tasks into smaller, manageable jobs that execute one after another, ensuring each step runs in its own transaction with fresh governor limits. Unlike @future methods, Queueable Apex supports both DML operations and callouts, making it ideal for workflows that require interacting with databases and external APIs. Additionally, Queueable jobs can chain themselves, meaning each job can enqueue the next step upon completion, maintaining the required sequential order. This design prevents governor limit issues like CPU timeouts or excessive DML operations, as each job operates independently. Alternatives like the Apex Scheduler lack the ability to chain jobs tightly, while @future methods cannot guarantee order or handle callouts and DML in the same context. The Limits class merely monitors limits reactively but doesn’t solve the root problem. By leveraging Queueable Apex, developers ensure scalability, error isolation, and efficient resource usage, making it the only robust solution for this scenario.

Explanation:

To retrieve the Show_Help__c preference for the current user while respecting hierarchy custom setting overrides, you must use the getInstance() method. Here’s why:

Hierarchy Behavior:

User_Prefs__c.getInstance() automatically checks for:
User-level overrides (if set).
Falls back to org-wide defaults if no user override exists.
This matches the requirement to "use defaults if the user hasn’t overridden preferences."

Correct Syntax:

The proper way to access the field is:

User_Prefs__c.getInstance().Show_Help__c;

getInstance() returns the most specific setting for the current user.

Why Other Options Fail:

A: getValuea() and Show_Help_co are invalid (typos).
B: getValues(UserId) forces a lookup for a specific user, ignoring the hierarchy’s fallback logic.
D: Direct field access (User_Prefs__c.Show_Help__c) is invalid—you must call getInstance() first.

Explanation:

The error:

“You have uncommitted work pending. Please commit or rollback before calling out.”

...occurs when DML (insert/update/delete) happens in the same transaction before a callout. Salesforce does not allow callouts and DML to be mixed unless they are properly sequenced.

Correct Practice:

Do all DML (record creation) before Test.startTest().
Perform mock callouts (e.g., via HttpCalloutMock) after Test.startTest().
Test.startTest() marks the boundary where governor limits are reset and is also the proper place to begin callouts in test methods.

Example:

@isTest
static void testCalloutLogic() {
// Create test data BEFORE callout
Account a = new Account(Name = 'Test Account');
insert a;

// Start test context and limits
Test.startTest();

// Register mock and invoke method that performs callout
Test.setMock(HttpCalloutMock.class, new MyMockCallout());
MyCalloutClass.performCallout(a.Id);

Test.stopTest();
}

Explanation:

One of the most critical functional differences between Visualforce components and Lightning components (Aura or LWC) is their support for server-side rendering and PDF generation.

Why B is correct:

Visualforce pages can be rendered as PDFs natively using the attribute.
Lightning components (LWC/Aura) do not support rendering as PDF directly — you'd need to use a third-party service or workaround.
So if your screen needs server-side PDF generation without third-party tools, Visualforce is required.

Explanation:

Salesforce provides a built-in BatchApexErrorEvent platform event that automatically fires when an unhandled exception occurs in a batch Apex job. This event contains valuable information such as the exception type, message, stack trace, and affected records. Since this event is published automatically, no additional publishing logic is required. Instead, the external system can subscribe to the BatchApexErrorEvent and listen for error notifications in real time.

This approach ensures that errors are captured efficiently without requiring manual intervention or additional Apex logic. The external system can process the event and take appropriate action, such as logging the error or triggering an automated response.

Explanation:

Since the external systems do not require Salesforce to wait for a response before continuing, the best approach is to use Platform Events. Platform Events provide an efficient publish-subscribe model, allowing Salesforce to notify external systems asynchronously when a record is created. This ensures that the integration process does not block Salesforce transactions and avoids governor limits associated with synchronous callouts.

Using Platform Events:

Decouples Salesforce from external systems, allowing them to process events independently.
Ensures scalability, as multiple external systems can subscribe to the same event.
Avoids callout limitations, since the event is published without requiring an immediate response.

Other options:

PushTopic event is used for streaming real-time updates but is not ideal for triggering external integrations.
Outbound messages are limited to workflow rules and do not provide the flexibility of Platform Events.
Trigger with HTTP callout would require synchronous execution, which is not recommended due to governor limits.

Explanation:

The corporation wants to build a single Java application that can create, retrieve, and update common object records across many different Salesforce orgs, some of which have different schemas.

Why Partner WSDL is the best choice:

The Partner WSDL is loosely typed and schema-flexible.
It allows the Java application to work with sObject types dynamically without needing to regenerate the WSDL for each Salesforce org.
Ideal for multi-org integration, where object definitions may differ.
Enables the app to read metadata at runtime and perform CRUD operations on standard/custom objects.

Explanation:

To display a dropdown list of all custom objects in a Lightning Web Component, the Apex method must:

Use the Schema class to get all SObject types.
Check each object’s describe result to determine if it is a custom object.
Return the list of custom objects to the LWC.

Why isCustom() is correct:

The isCustom() method of the DescribeSObjectResult class returns true if the object is custom.
You can loop through all SObjects using Schema.getGlobalDescribe() and filter for custom objects using describeResult.isCustom().

Explanation:

Custom metadata is the best choice for storing and packaging configuration settings in an AppExchange application. It allows developers to define metadata records that can be deployed with the managed package, ensuring that best practice settings are included by default while still allowing customers to modify them as needed.

Key advantages of using custom metadata:

Deployable with the AppExchange package – Unlike custom settings, custom metadata records can be included in the package, ensuring that default configurations are available upon installation.
Configurable per org – Customers can modify the metadata records to suit their specific needs without requiring code changes.
Efficient retrieval – Custom metadata is cached and does not count against SOQL query limits, making it ideal for frequently accessed configuration data.

Other options:

Custom objects – Not ideal for configuration settings because they require manual data entry and cannot be packaged with default values.
Custom settings – While useful for storing org-specific configurations, they cannot be packaged with predefined records in a managed package.
Custom labels – Used for storing translatable text, not for configuration logic.

Explanation:

Rendering thousands of records at once in a Visualforce page can significantly impact performance, leading to slow load times and potential view state issues. The best approach to mitigate this is to implement pagination using the standard Account List controller or a custom pagination mechanism. This ensures that only a subset of records is displayed at any given time, reducing the processing load and improving responsiveness.

Other options:

A. JavaScript remoting can help reduce server-side processing but does not directly address the issue of excessive data rendering.
B. The transient keyword is useful for reducing view state size but does not solve the problem of loading too many records at once.
C. A third-party data table library may improve UI rendering but does not optimize the underlying data retrieval process.