PDI Practice Questions

The most efficient approach is to offload as much processing as possible to the database. A single aggregate SOQL query can retrieve all the necessary information in one database round trip. By querying QA_Review__c, grouping by the Case__c lookup, and selecting the relevant fields, you can efficiently get the data for the most recent review for each case. This result can then be used to populate a Map or a list of wrapper classes, avoiding loops with SOQL queries and ensuring the solution is scalable and performant. This minimizes Apex CPU time and avoids hitting the SOQL query limit.

For a successful deployment to production, all components (the Apex class and the custom field) must be in the change set. The Apex class must have an accompanying test class (which also must be in the change set) that provides at least 75% code coverage for the class being deployed. The overall code coverage in the production org must also be at least 75% after the deployment. Field-level security for profiles can be included in the change set and does not have to be configured manually.

In the Salesforce MVC pattern, the 'Model' represents the data structure and database. This corresponds directly to the Standard and Custom Objects, along with their fields and relationships, which define the schema and how data is stored in the Salesforce database. The 'View' is the user interface (Visualforce, Lightning Components), and the 'Controller' is the business logic (Apex).

The standard and most efficient way to prevent trigger recursion within a single transaction is to use a static boolean variable. Static variables retain their value for the duration of the transaction. A common pattern is to have a helper class with a static boolean hasRun variable, initialized to false. The trigger checks this variable upon entry. If it's false, it sets it to true and executes the logic. If it's true, it bypasses the logic, thus breaking the recursive loop. This is more performant than querying a custom setting.

The correct data model is a Master-Detail relationship to Position__c and a Lookup relationship to Candidate__c. The requirement for cascading deletion (deleting a Position deletes its Applications) directly points to a Master-Detail relationship, where Position__c is the master. The requirement that deleting a Candidate__c should be prevented if applications exist (but not cascade delete them) points to a Lookup relationship. A standard lookup relationship with the "Don't allow deletion of the lookup record that's part of a lookup relationship" option selected will enforce this behavior. An object can have at most two master-detail relationships, but the behavior described for the Candidate__c object perfectly matches a lookup.

The most robust solution is an Apex trigger on the 'before delete' event. Validation rules do not fire on delete operations, so they cannot be used to prevent record deletion. A 'before delete' trigger can inspect the records being deleted, check the user's profile, and use the .addError() method on the records that should not be deleted, effectively blocking the DML operation. This approach is secure and directly addresses the requirement which cannot be met by declarative tools.

The best approach is to use a wrapper (or inner) class within a custom controller. The wrapper class will contain the Contact sObject and a boolean property to track the checkbox state. The Visualforce page will iterate over a list of these wrapper objects in an or . This pattern allows the controller to easily identify which records were selected when the user submits the form, enabling efficient bulk processing.

Salesforce prevents performing a callout after a DML operation within the same transaction to avoid data integrity issues. Even in a test context with mock callouts, this rule is enforced. The DML statement (update account;) starts a transaction that is not committed until the test method finishes. The after update trigger attempts the callout within this transaction, causing the 'uncommitted work pending' error. To resolve this, the callout logic must be moved to an asynchronous method (like a @future method), and the test must use Test.startTest() and Test.stopTest() to ensure the DML is committed before the asynchronous logic executes.

This scenario describes a many-to-many relationship between Student and Course, implemented with Enrollment__c as the junction object. The requirement that enrollments are deleted when a student is deleted indicates a cascading delete behavior, which is a key feature of a Master-Detail relationship. Therefore, Enrollment__c must have a Master-Detail relationship to Student__c. The relationship to Course__c can be a Lookup, as there's no stated requirement for cascading deletion when a course is deleted. An object can have at most two master-detail relationships, but in this case, only one is strictly required by the prompt, making this the most appropriate and common configuration.

To process millions of records, Batch Apex (using the Database.Batchable interface) is the correct choice as it processes records in manageable chunks, respecting governor limits. To run the job nightly, the class must also implement the Schedulable interface. Within the start method of the batch class, a Database.QueryLocator must be used to build the scope of records to process. A QueryLocator can handle up to 50 million records, making it essential for large data volumes.