Plat-Dev-301 Exam Dumps and Practice Questions

In Visualforce, the 'View State' is a hidden form field that maintains the state of the page (and the controller's variables) across postbacks to the server. If the View State becomes too large, it can slow down page loads and eventually hit the Salesforce View State limit (170KB), causing the page to crash.

The transient keyword is used to declare instance variables in Apex controllers that should not be saved in the View State. When a variable is marked as transient, its value is discarded after the request finishes and is not transmitted back to the client. This effectively reduces the size of the View State. It is commonly used for data that is needed only for the duration of the current request (like a large list of records displayed in a read-only table) and can be easily requeried or recalculated if needed.

The 'SOQL query not selective enough' error occurs when a query on an object with a large volume of records (typically over 200,000) does not use a filtered index to narrow down the result set effectively. In Sales1force,2 the query optimizer must be able to use an index to scan a small enough percentage of the total records to maintain performance. When a query filters on a non-indexed field, the system is forced to perform a full table scan, which triggers this exception to prevent performance degradation.

To resolve this, the developer must ensure that the field used in the WHERE clause is indexed. Marking a custom field as an 'External ID' or 'Unique' automatically creates a custom index on that field. By marking ERP_Number__c as an External ID, the platform generates a underlying database index, allowing the query optimizer to quickly locate matching records without scanning the entire table. While the LIKE operator with a trailing wildcard (e.g., 'Text%') can utilize an index, it will only be considered 'selective' if the filter narrow the results below the platform's selectivity thresholds (typically 10% of the first million records). Making the field an External ID is the standard programmatic solution to provide the necessary indexing for selectivity. Option A is incorrect because moving a non-selective query to an asynchronous process does not change the fact that it is non-selective; it will still fail.

For storing application configurations and integration settings that need to be easily modified by administrators and deployed across environments, Custom Metadata Types are the preferred solution. Unlike Custom Settings (Options A and D), records within a Custom Metadata Type are considered metadata rather than data. This is a critical distinction for the development lifecycle because these records can be included in Change Sets or deployment packages. This eliminates the manual overhead and risk associated with re-creating configuration records in production after a sandbox deployment.

In this scenario, UC needs to manage settings for two different payment processors. A Custom Metadata Type can be created with fields for API endpoints, merchant IDs, and security keys. An administrator can then create and edit the specific records for the 'Individual' and 'Corporate' processors directly in the Setup menu. Furthermore, Custom Metadata queries are efficient and do not count against standard SOQL governor limits in many contexts. While Custom Labels (Option B) are useful for translating text, they are not intended for complex, structured configuration data. Hierarchy Custom Settings are designed for user-specific overrides, which is not applicable here. Therefore, Custom Metadata provides the most robust, deployable, and administrator-friendly way to manage external service configurations.

In Salesforce Apex, a @RemoteAction method must be defined as static. Static methods belong to the class itself rather than to a specific instance of the class. Therefore, when writing a unit test to verify the behavior of a RemoteAction, the method should be called using the class name notation (ClassName.methodName) rather than by instantiating the class first.

Option D correctly demonstrates the standard way to invoke a static method in Apex: Account a = MyRemoter.getAccount('TestAccount');. Because the method is static, it does not require the new keyword or a constructor to be called. Option A is incorrect because it attempts to call a static method on an instance variable (remote.getAccount), which is considered an illegal or improper reference in Apex. Option B is incorrect because it treats the RemoteAction like an instance method and assumes a non-existent constructor that takes a String. Option C is incorrect because it uses an undefined variable controller.

By calling the method statically in the test, the developer correctly simulates how the Visualforce Remoting engine calls the method from JavaScript at runtime. The assertion System.assertEquals then verifies that the record retrieved from the database matches the expected name, ensuring the search logic is functioning correctly.

To perform historical auditing and analysis of user behavior---such as tracking the last login time---Salesforce provides Event Monitoring (Option C). This feature captures a wide range of 'Event Types,' including logins, logouts, URI (page) clicks, and API calls.

These events are stored in EventLogFile objects. Each day, Salesforce generates log files for the previous day's activity. A developer can query these files or use tools like the Salesforce Event Log File Browser to see a comprehensive history of user logins. This is the correct choice when real-time alerts are not necessary and the goal is to analyze patterns over time.

Option A refers to Change Data Capture, which is for tracking record changes, not user sessions. Option B is for the standard Salesforce Calendar. Option D (Developer Log) is used for debugging Apex and system execution in the short term and does not provide a reliable or long-term history of user login events. Event Monitoring provides the high-fidelity audit trail required for compliance and security analysis.