Salesforce Plat-Dev-301 Exam Questions

38

In Salesforce, all triggers that fire as a result of an initial DML operation ru39n within the same execution context and the same transaction. This means that all governor limits---such as the limit of 10,000 records processed by DML statements---are shared across the entire chain of events.

In this scenario, the transaction begins with the update of 200 Accounts. The Account trigger then attempts to update 10,000 related Contacts (50 Contacts per Account across 200 Accounts). This update of 10,000 Contacts then fires the Contact trigger, which attempts to update 10,000 related Campaign Members. When the system attempts to process these updates, the total number of records processed via DML in a single transaction will exceed the platform limit of 10,000 rows.

Even though the Account update is only 200 records, the subsequent cascading updates (10,000 Contacts + 10,000 Campaign Members) bring the total DML count to 20,200. This triggers a LimitException, and because Apex transactions are atomic, the entire operation will fail and roll back. To resolve this, the developer would need to handle these updates asynchronously (e.g., using Batch Apex or Queueable) to split the cascading updates into separate transactions with their own sets of governor limits.

==========

18

In the Aura Component framework, communication between components is handled via events. When two components need to communicate but do19 not share a direct parent-child relationship---such as a kiosk registration component on a page and an alert component residing in the global utility tray---an Application Event (Option C) is required.

Application events follow a 'publish-subscribe' model. One component fires the event, and any other component in the application that has a handler for that specific event type can listen for and react to it, regardless of where they sit in the component hierarchy. This is distinct from a Component Event (Option D), which is restricted to bubbling up the component containment hierarchy (from child to parent).

While modern implementations might also consider the Lightning Message Service (LMS) for cross-framework communication (between Aura, LWC, and Visualforce), within the specific context of Aura-to-Aura communication for decoupled components like utility bar items, Application Events remain the fundamental architectural solution. DML Operations (Option A) and ChangeLogs (Option B) are database-level concepts and do not provide the real-time, client-side notification capabilities needed for a UI alert system.

==========

22

In Apex, 'bulkification' is the practice of ensuring code can handle multiple records efficiently without hitting governor limits. Snippet A demonstrates the correct bulkified approach for this requirement. It first iterates through the opportunityList to collect all unique AccountId values into a Set. Then, it performs a single SOQL query to retrieve all relevant Accounts and their child Contacts using a subquery (Inner Join). This ensures that the code only consumes one SOQL query regardless of how many opportunities are in the input list.

Snippet B is syntactically incorrect and will fail to compile. In Apex, you cannot use dot-notation (like opportunityList.AccountId) on a List collection to retrieve a set of IDs from its elements. To access the AccountId of records within a list, you must iterate through the list or use a map. Even if corrected to use a proper ID collection, Snippet A is often preferred when you need the relationship context between the Account and its Contacts. Most importantly, Snippet A correctly identifies the need to extract IDs into a separate collection before querying, which is a fundamental requirement for writing scalable Apex. It avoids the 'Query in a loop' anti-pattern and adheres to the platform's execution model.

==========

Comprehensive and Detailed 1

The fundamental principle of DRY (Don't Repeat Yourself) in Apex development dictates that logic used in multiple places should be centralized. For API integrations, this typically invo2lves creating a Utility or Service Class (Option A).

This class handles the common 'plumbing' of the integration:

Retrieving Named Credentials.

Setting headers (Content-Type, Timeout).

Standardizing error handling and logging.

Serializing and deserializing JSON payloads.

By invoking this central class from various triggers, batch jobs, or controllers, the developer ensures that any change to the API (such as a version update or header change) only needs to be made in one place. Option B leads to 'class sprawl' and duplicate boilerplate code. Option C is incorrect as Static Resources cannot contain executable Apex code. Option D is the definition of poor maintainability.

Comprehensive and Detailed

When dealing with Large Data Volumes (LDV)---specifically in the range of hundreds of thousands to millions of records---the Bulk API (Option C) is the only optimal choice.

The Bulk API is based on REST principles but is optimized for processing large sets of data asynchronously. Instead of processing records one by one or in small synchronous chunks (which would hit time limits and consume many API calls), the Bulk API allows you to upload a CSV file or JSON batch. Salesforce then processes these records in the background using parallel processing.

Options A and B (REST/SOAP) are designed for real-time, synchronous interactions with a limited number of records and would hit rate limits or timeout for millions of records. Option D is for custom logic and is subject to the same synchronous execution limits as standard REST.