Ace the Salesforce PDII Exam: Ultimate Preparation Guide

The Storage tab in the Salesforce Lightning Inspector can be used to view and manage data stored on the client side, such as in the cache. This is useful for diagnosing issues related to stale or outdated cache data that may prevent the most current reference data from displaying.References: Salesforce Lightning Inspector Chrome Extension

The error 'Attempt to dereference a null object' often occurs when trying to access a member of a null object. By checking if the object is null in the getter method and returning a new instance if it is, the error can be prevented.

References:

• Apex Developer Guide

For optimizing queries, especially on large data volumes, it's recommended to use indexed fields such as External ID fields, which will make the queries selective. Among the options given:

• B) is optimized because it is using the Customer_Number__c field, which is an External ID and hence indexed.
• D) is also optimized because it filters out deleted records with IsDeleted = false and uses Name != ' ', which is likely to be selective.

Using indexed fields and filtering out unnecessary records helps in faster query execution on large data volumes.

References:

• Make SOQL Query Selective
• Working with Very Large SOQL Queries

To make the Aura component responsive, the developer should set multipleRows="true" to allow the layout items to wrap onto multiple rows on smaller devices. Additionally, setting the size attribute for different device sizes ensures that the layout adapts to the screen width.References: Lightning Components Developer Guide - lightning:layout

The System.CalloutException with the message "Unauthorized endpoint" typically indicates that the endpoint to which the callout is being made has not been authorized in the Salesforce org's security settings. To resolve this, the developer must navigate to the Remote Site Settings in the Salesforce Setup and add the endpoint URL as a new remote site. This step is necessary to authorize the Salesforce org to send outbound callouts to that specific endpoint. Annotating with @Future(Callout=true) is necessary for making callouts from methods that perform DML operations, but it does not resolve endpoint authorization issues. Similarly, changing the access modifier or using SetHeader() for authentication would not address the unauthorized endpoint error.

References:

• Remote Site Settings
• Apex Developer Guide: Making Callouts Using Apex

Using a dedicated sandbox for testing before deployment can prevent issues like overwriting changes in production. When administrators deploy their own change sets without coordination, they might inadvertently overwrite each other's changes, including page layouts. References: Best Practices for Deployments with Change Sets

To improve performance, the developer should specify only the fields needed by using the fields attribute in the lightning-record-form instead of loading all fields with layout-type="Full". This reduces the amount of data being retrieved and processed, thus improving the component's performance.References: Lightning Web Components Developer Guide - lightning-record-form

To improve the performance of an Aura component that is loading slowly, the developer can make the following change:

• D. Change the default for showContactInfo to “False": By setting the default value of showContactInfo to False, the component does not fetch or render the contact information by default, which can reduce the initial load time. The information can be fetched and displayed later based on user action or other triggers.

Changing the type of contactInfo to "Map" (Option A) or moving the contents of <c:contactInfo> into the component (Option B) may not necessarily improve load times. Adding a change event handler for showContactInfo (Option C) adds more processing and can potentially slow down the component if not handled efficiently.

References:

• Lightning Components Performance Best Practices: Improve Performance