SF-PD2 Practice Test 5 — 25 Questions

Question 1

A developer is optimizing an Apex batch job that processes millions of records and must stay within governor limits while finishing in a reasonable time. Which TWO techniques improve performance and scalability for this batch job? (Choose two.)

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Reduce the batch size so each execute method handles fewer records, lowering heap and CPU usage per transaction.. QueryLocator in the start method lets the batch stream very large result sets beyond the standard SOQL row limit, and a smaller batch size keeps each execute transaction under heap and CPU limits. Together they make a millions-of-records job complete reliably within governor constraints.

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Increase the batch size to the maximum so fewer total transactions are needed.

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Call Database.executeBatch from within the execute method to parallelize the work.

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Perform all DML inside the start method so the execute method only reads data.

Question 2

A developer is building a Visualforce page that displays a table of 1,000 Contact records. The page uses a standard controller with an extension that queries all Contacts in the constructor. Users report that the page loads slowly. Which change should the developer make to improve performance?

Accepted Answer

Use a StandardSetController to enable pagination and reduce the number of records displayed per page.. StandardSetController is designed for paginating large data sets in Visualforce. By limiting the number of records per page, it reduces the initial query size and the amount of data rendered, leading to faster page loads. It also provides built-in navigation and sorting, making it a straightforward solution for improving performance.

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Add a rendered attribute to the table to conditionally display it after the page loads.

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Increase the view state by storing all Contacts in a transient variable.

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Use JavaScript remoting to load the Contacts asynchronously after the page renders.

Question 3

A developer is writing an Apex test class for a service that must be resilient against partial failures. The service calls a REST endpoint using a callout and, when the callout succeeds, performs a DML update on a set of Account records. The developer wants the test to simulate the HTTP response without hitting the real external system. Which approach should the developer use?

Accepted Answer

Implement the HttpCalloutMock interface and register it with Test.setMock(HttpCalloutMock.class, new MyMock()) before the callout is invoked.. The Apex testing framework provides Test.setMock with an HttpCalloutMock implementation precisely so callouts can be exercised without external dependencies. Registering the mock before the request executes makes the runtime substitute the developer-defined HttpResponse, letting assertions validate both the request built by the code and the handling of the response, including error status codes.

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Create the mock response by inserting a ContentVersion record and reference it from the callout using the endpoint URL of the mock.

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Annotate the test method with @IsTest(SeeAllData=true) so the test can reach the live endpoint and then assert on the returned payload.

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Wrap the callout in Test.startTest() and Test.stopTest() so the platform automatically intercepts the outbound request and returns a synthetic 200 response.

Question 4

A developer needs a Visualforce page to display account data and also expose a REST endpoint that returns the same data to an external system. The developer wants to reuse the query and business logic. Which approach best satisfies this requirement?

Accepted Answer

Create a service class containing the query and business logic, then call it from both the Visualforce controller and the REST resource class.. The cleanest reuse pattern places query and business logic in a service class that is agnostic to the caller. A Visualforce controller handles page binding while the REST resource handles HTTP concerns, and both delegate to the service. This keeps the logic testable and avoids duplication, whereas controller extensions, remoting, and trigger handlers are tied to specific contexts and cannot serve both callers well.

Answer

Place the query and logic in a controller extension, then call that extension from the REST resource class.

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Implement the logic in a trigger handler and invoke it from both the Visualforce controller and the REST resource.

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Expose the REST endpoint and have the Visualforce page call it using JavaScript remoting.

Question 5

A developer is optimizing a Visualforce page that displays a table of 1,000 custom object records. The page uses a StandardSetController and currently loads all records at once, causing slow rendering. The developer wants to implement pagination to improve performance. Which approach should be used?

Accepted Answer

Set the page size to 20 and use the StandardSetController's next() and previous() methods to navigate pages.. StandardSetController is designed for pagination in Visualforce. By setting a smaller page size, only a subset of records is rendered at a time, reducing page load and rendering time. Navigation methods handle fetching subsequent pages efficiently. This is the recommended approach for displaying large datasets in Visualforce pages without hitting view state limits.

Answer

Use an <apex:repeat> component with a rendered attribute to conditionally display only a subset of records based on a counter.

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Replace the StandardSetController with a custom controller that uses SOQL OFFSET to fetch records for each page.

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Enable view state and set the page's cache attribute to true to store all records in the browser cache.

Question 6

A developer is implementing a complex business process that requires calling an external web service, then updating multiple related records, and finally sending an email. The entire process must be atomic; if any step fails, all changes must be rolled back. Which approach should the developer use?

Accepted Answer

Implement a compensation mechanism: perform the callout, then DML in a separate transaction, and if DML fails, invoke a compensating callout to undo the external action.. Atomicity across external callouts and Salesforce DML is not natively supported because callouts cannot be rolled back. The developer must use a compensation pattern: if the subsequent DML fails, a compensating callout is made to undo the external action. This ensures that the overall process either completes fully or is compensated, maintaining data integrity across systems.

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Use a Database.Savepoint and rollback in a single transaction, with the callout performed before the savepoint.

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Perform all operations in a single Apex transaction, using a callout followed by DML and email.

Answer

Use a Queueable Apex job to perform the callout, then chain a second Queueable to perform DML and send email.

Question 7

A developer is writing a trigger on a custom object that processes up to 200 records at a time. The trigger currently performs a SOQL query inside a loop to retrieve related records for each record. This causes the trigger to hit governor limits. What is the best practice to refactor the trigger for performance?

Accepted Answer

Move the SOQL query outside the loop and use a Map to correlate related records with the trigger records.. Bulkifying the SOQL query by moving it outside the loop and using a Map to correlate related records is the most efficient approach. This reduces the number of queries to one, avoiding governor limits and improving performance. Other options either do not address the root cause or introduce unnecessary complexity.

Answer

Use a SOQL query with a subquery to retrieve related records for all trigger records in one query, then process the results in the loop.

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Use a SOQL query with a WHERE clause that filters by the trigger records' IDs, and then loop through the results to update each record.

Answer

Use a SOQL query for each record but add a LIMIT clause to reduce the number of rows returned.

Question 8

A developer is deploying a new Apex class to production using a change set. The class contains a method that performs a callout to an external web service. During deployment, the developer receives an error: 'Callout not allowed from a test method.' Which action should the developer take to resolve this error while ensuring the test method still validates the callout logic?

Accepted Answer

Implement the HttpCalloutMock interface and use Test.setMock to simulate the callout response in the test method.. The correct solution is to implement HttpCalloutMock and use Test.setMock, which allows the test to simulate the callout response without making a real callout. This adheres to Salesforce's testing requirements and ensures the callout logic is properly validated. Other options either do not resolve the error or compromise test coverage.

Answer

Use Test.isRunningTest to conditionally skip the callout when the test is executing.

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Move the callout logic to a future method and call it from the test method.

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Wrap the callout in a try-catch block to suppress the error during test execution.

Question 9

A developer is building a Lightning Web Component that must navigate to a new record's detail page after the record is created via a custom form. The component uses NavigationMixin. Which navigation type should the developer use to navigate to the newly created record?

Accepted Answer

standard__recordPage with attributes recordId and actionName set to 'view'.. NavigationMixin supports several page reference types, and standard__recordPage is specifically designed to open a record's detail page. By providing the recordId of the newly created record and setting actionName to 'view', the component navigates the user to the standard record view. Other page reference types target object home pages, custom tabs, or external URLs and do not open a specific record.

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standard__webPage with attributes url set to the record's URL.

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standard__objectPage with attributes objectApiName and actionName set to 'new'.

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standard__navItemPage with attributes apiName set to the object's API name.

Question 10

A developer is writing a test class for a service that makes callouts to an external web service. The test method needs to simulate the callout response without making an actual HTTP request. (Choose two.)

Accepted Answer

Implement the HttpCalloutMock interface and use Test.setMock(HttpCalloutMock.class, mock).. To simulate callouts in Apex tests, developers can use HttpCalloutMock for HTTP callouts or WebServiceMock for SOAP callouts. Both require implementing the respective interface and registering the mock with Test.setMock. This intercepts the callout and returns a controlled response. Test.startTest and Test.stopTest do not simulate callouts, and SeeAllData does not affect callouts.

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Use @isTest(SeeAllData=true) to access external data.

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Use Test.startTest() and Test.stopTest() to isolate the callout.

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Set the callout to run asynchronously to avoid the callout limit.

Question 11

A developer is preparing to deploy a change set from a sandbox to production. The change set includes a new custom object, its fields, a Visualforce page, and an Apex controller. After uploading the change set, the developer notices that the custom object and fields are missing from the change set components. What is the most likely reason?

Accepted Answer

The custom object and fields were not explicitly added to the change set when it was created.. Change sets do not automatically include dependencies. When a developer adds a Visualforce page or Apex class, the associated custom object and fields are not added automatically. The developer must manually add each component. Therefore, the missing object and fields are due to them not being explicitly added during change set creation.

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The change set was created in a sandbox that is not the source of the custom object and fields.

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The custom object and fields are only available in the sandbox and cannot be deployed to production.

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The custom object and fields were not added to the change set because they are not supported in change sets.

Question 12

A developer is writing an Apex test class for a service that calls an external REST endpoint via a callout. The test must verify the parsing logic without hitting the external system, and it must also assert that the service throws a custom exception when the endpoint returns a 500 status. Which combination of techniques is required?

Accepted Answer

Use HttpCalloutMock to return a 200 response for the happy path, and use Test.setMock with a separate mock returning a 500 response to assert the exception.. Tests cannot perform real callouts, so HttpCalloutMock injected via Test.setMock supplies a controllable HttpResponse. Using one mock that returns status 200 exercises the parsing logic, while a second mock returning status 500 drives the error branch so the custom exception can be asserted, covering both paths with no external dependency.

Answer

Use a WebServiceMock implementation, since WebServiceMock is the only interface that supports simulating HTTP responses in tests.

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Use Test.setMock with HttpCalloutMock and set the mock's response status to 500 for both the happy path and the error path.

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Use Test.isRunningTest within the service to branch around the callout logic and return hardcoded values.

Question 13

A developer is writing a test class for an Apex trigger that fires on Account insert and update. The trigger makes a callout to an external service to validate the account's billing address. The test class uses Test.setMock to mock the callout. However, when running the test, the callout is still attempted and fails with a 'Callout not allowed from test method' error. What is the most likely cause?

Accepted Answer

The mock class does not implement the HttpCalloutMock interface correctly, or Test.setMock was not called before the callout.. In Apex tests, callouts must be mocked using Test.setMock with a class that implements HttpCalloutMock. If the mock is not set before the callout, or if the mock class is incorrectly implemented, the test will attempt a real callout and fail with 'Callout not allowed from test method'. Ensuring the mock is properly implemented and set before the callout is the correct solution.

Answer

The trigger is performing the callout in a before insert context, which does not allow callouts.

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The test method does not use Test.startTest() and Test.stopTest() around the callout.

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The test class does not have the @isTest(SeeAllData=true) annotation, so it cannot access the external service.

Question 14

A developer is building an Apex REST service that external systems will call to create records in Salesforce. The service must enforce field-level security (FLS) and sharing rules for the running user. Which approach should the developer take to ensure these security requirements are met?

Accepted Answer

Use the 'with sharing' keyword on the Apex class and manually enforce FLS using the Schema.DescribeFieldResult class.. To enforce sharing and FLS in an Apex REST service, the class must be declared 'with sharing' to respect sharing rules, and FLS must be manually enforced using Schema methods or Security.stripInaccessible. Apex runs in system mode by default, so explicit measures are required. The other options either ignore sharing, assume automatic FLS, or use an inappropriate sharing keyword.

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Use the 'without sharing' keyword and rely on the external system to send only authorized data.

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Use the 'inherited sharing' keyword to automatically apply the sharing mode of the calling class.

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Use the 'with sharing' keyword and assume that FLS is automatically enforced for Apex REST services.

Question 15

A developer is implementing a Queueable Apex job that makes a callout to an external REST service and then updates records in Salesforce. The job must handle failures gracefully and allow chaining to a second job if needed. Which two practices should the developer follow? (Choose two.)

Accepted Answer

Implement the Database.AllowsCallouts interface in the Queueable class.. To make callouts from a Queueable job, the class must implement Database.AllowsCallouts. To chain a second job and handle errors gracefully, the developer should use System.enqueueJob within the execute method and implement the Finalizer interface. These two practices ensure the job can perform callouts and manage chaining and error handling as required.

Answer

Use the @future annotation with (callout=true) to make the callout, and chain a new future method for subsequent processing.

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Use the System.schedule method to schedule the job to run at a later time, and handle errors with a try-catch block.

Answer

Implement the Database.Stateful interface to maintain state across chained jobs.

Question 16

A developer needs to write a unit test for an Apex class that performs a callout to an external REST endpoint. The test must not make a real HTTP request and must simulate a successful response with a specific status code and body. Which approach should the developer use?

Accepted Answer

Implement HttpCalloutMock and register it with Test.setMock before invoking the callout.. HttpCalloutMock is the platform-provided mechanism for stubbing callouts in tests. Implementing respond() and registering the mock with Test.setMock allows the test to return a controlled HttpResponse with a specified status code and body. Other techniques do not prevent the real callout or produce the desired simulated response.

Answer

Use System.assert with a try-catch block to intercept the callout exception and convert it into a fake response.

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Use Test.startTest and Test.stopTest around the callout to suppress the actual HTTP request.

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Set the endpoint URL to a localhost address so the callout fails and returns a simulated error.

Question 17

A developer is optimizing a Visualforce page that displays a large list of Accounts with related Contacts. The page currently uses a standard controller with an <apex:pageBlockTable> and a controller extension that queries all Contacts for each Account in a loop. Users report that the page loads slowly and sometimes times out. Which technique should the developer implement to improve performance?

Accepted Answer

Use a single SOQL query with a subquery to retrieve all Accounts and their Contacts, then iterate over the results to build a map for the page.. Using a single SOQL query with a subquery to fetch Accounts and their Contacts in one call eliminates the N+1 query problem, where a separate query is made for each Account's Contacts. This reduces database load, avoids governor limits, and significantly improves page load time. The developer should then process the results into a map for efficient access in the Visualforce page.

Answer

Enable lazy loading on the <apex:pageBlockTable> by setting the 'reRender' attribute to load Contacts only when a user expands a row.

Answer

Implement pagination using the StandardSetController to limit the number of Accounts displayed per page, thereby reducing the number of Contacts queried.

Answer

Cache the Contact records in Platform Cache and retrieve them on subsequent page loads to avoid repeated queries.

Question 18

A developer is building a Lightning Web Component that must expose a public method callable from an Aura component on the same page. The method accepts a string and returns a promise that resolves with a boolean. Which TWO steps are required to make this method callable from the Aura parent? (Choose two.)

Accepted Answer

Annotate the method with @api and declare it as a public property or method on the Lightning Web Component class.. Exposing a Lightning Web Component method to an Aura parent requires two things: the method must be decorated with @api so the framework registers it as public, and the Aura parent must obtain the element reference, typically via component.find with an aura:id, to call that method. The promise returned is handled asynchronously by the Aura caller, matching the stated contract.

Answer

Register the method name in the component's .js-meta.xml file under the targetConfigs section.

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Wrap the Lightning Web Component inside an aura:method declaration so the Aura parent can call it directly.

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Add the method to the component's exported functions list using the export keyword alongside the @api decorator.

Question 19

A developer needs to write an Apex test class for a service that makes a callout to an external REST API. The test method must simulate the callout response without making an actual HTTP request. Which approach should the developer use?

Accepted Answer

Implement the `HttpCalloutMock` interface and use `Test.setMock` to register the mock before calling the service method.. The correct approach is to implement the `HttpCalloutMock` interface and register it with `Test.setMock`. This allows the test to simulate the external API response without making a real HTTP request. Other options do not provide a way to mock callouts; they either do not prevent the callout or are unrelated to mocking.

Answer

Annotate the test method with `@isTest(SeeAllData=true)` to allow the callout to access external data.

Answer

Replace the callout with a `@future` method and test the future method using `Test.stopTest` to force execution.

Answer

Use `Test.startTest` and `Test.stopTest` to isolate the callout and prevent it from executing during the test.

Question 20

A developer is creating a Lightning Web Component that will be placed on a Lightning record page for the Case object. The component must display the case's subject and status. Which approach correctly retrieves the record data so the component updates automatically when the record changes?

Accepted Answer

Import getRecord from lightning/uiRecordApi and wire it with the recordId property, then reference fields on the returned record.. The getRecord wire adapter from lightning/uiRecordApi provides a reactive subscription to a single record through Lightning Data Service. Wiring it with the recordId property means the component receives updates whenever the record changes, satisfying the automatic refresh requirement. Apex calls, form components, and notify-change utilities do not provide this reactive single-record retrieval pattern.

Answer

Use the lightning-record-form base component and read its output attributes to populate the display.

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Call an Apex method from connectedCallback that queries the Case by Id and assign the result to a tracked property.

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Import getRecordNotifyChange and call it inside renderedCallback to fetch the latest field values.