Free Platform Developer II sample questions

Correct answer: Return a `Database.QueryLocator` from a SOQL query on the `Product__c` object.

For processing large data sets (over 50,000 records), `Database.QueryLocator` is the optimal choice for the `start` method of a Batch Apex class. It bypasses the heap size limit for the total number of records retrieved by the query because it fetches records in chunks. In contrast, returning an `Iterable` or a `List ` loads all records into the heap at once, which would cause a heap limit exception with over 1 million records.

Correct answers: Enclose the callout logic within `Test.startTest()` and `Test.stopTest()` blocks.; Implement the `HttpCalloutMock` interface and use `Test.setMock` to provide a fake response.

Correct answer: Declare the List variable that holds the `Opportunity` records with the `transient` keyword.

The view state error is caused by large amounts of data being stored in the controller's properties between server requests. The `transient` keyword prevents a variable from being saved as part of the view state. While this means the data will need to be re-fetched on each postback, it directly solves the 'Maximum view state size' error by removing the large data list from the view state.

Correct answer: Use Custom Metadata Types with metadata relationships to model the data structure.

Custom Metadata Types are the best fit for this scenario. They are deployable, meaning the configuration data can be moved between environments as metadata. They can be queried using SOQL, and they support relationships, allowing the developer to model the parent-child structure between 'Service Levels' and 'Country Surcharges'. Custom Objects are data, not metadata, and are harder to deploy. Custom Settings are not as well-suited for complex relational structures and are less easily deployed.

Correct answer: Request Salesforce Support to create a custom index on the `LastLoginDate` field.

The query is timing out because it is non-selective. It has to perform a full table scan on 10 million records to find contacts where `LastLoginDate` is older than 180 days. Standard date fields like `LastLoginDate` are not indexed by default. The most effective solution is to work with Salesforce Support to create a custom index on this field. This will make the query highly selective and allow it to execute efficiently without timing out.

Correct answer: True

This statement is true. The External ID field must uniquely identify a single record for the `upsert` operation to succeed. If the value of the External ID field is not unique and matches multiple existing records, the operation will fail and a `DmlException` will be thrown, indicating that multiple records were found for the upsert.

Correct answer: `@InvocableMethod`

The `@InvocableMethod` annotation is specifically designed to expose an Apex method as a callable action in declarative tools like Process Builder, Flow, and the REST API. The method must be static and can have only one parameter, which must be a list of a primitive data type or a custom Apex class.

Correct answer: A class that implements the `Queueable` interface.

Queueable Apex is the best fit. It runs asynchronously, so it won't delay the Opportunity save. Crucially, a Queueable job can enqueue another job from within its `execute` method, which allows for complex patterns like implementing a retry mechanism. The job can maintain a `retryCount` state variable and, upon failure, re-enqueue itself if the count is below the threshold. `@future` methods cannot call other `@future` methods, and Batch Apex is overkill for a single callout.

Correct answer: Use a static Boolean variable in a utility class to track execution.

The standard and recommended best practice for preventing trigger recursion within a single transaction is to use a static Boolean variable. A utility class holds the static variable (e.g., `hasAlreadyRun`). The trigger checks this variable before executing its logic. If it's false, it sets it to true and runs the logic. If it's already true, it bypasses the logic, preventing the recursive call from re-executing.

Correct answer: Use Custom Labels and reference them in the Visualforce page with the `$Label` global variable.

Custom Labels are the standard Salesforce feature for storing translatable text. By creating a Custom Label for each piece of text and referencing it in Visualforce with the syntax `$Label.MyLabelName`, the platform will automatically display the correct translation based on the user's language setting, provided that translations have been entered in the Translation Workbench.