Introduction
Welcome to Part 2 of our series on Asynchronous Apex Interview Questions!
In this post, we’ll build on the foundational knowledge from Part 1 and explore 25 more questions that delve deeper into advanced topics like Batch Apex state management, Queueable Apex chaining, and interactions between different types of asynchronous processes. These questions are designed to help you understand the importance of Asynchronous Apex and prepare you for real-world scenarios and complex interview questions.
From understanding how to maintain state in Batch Apex to chaining Queueable jobs and handling governor limits, this post will equip you with the knowledge to tackle even the most challenging aspects of Asynchronous Apex.
If you missed Part 1 of our series on 25 Salesforce Interview Questions on Asynchronous Apex, be sure to check it out in the link below!
Let’s dive in and continue our journey to mastering asynchronous processing in Salesforce!
26. Can you call a Queueable Apex job from a Future Method?
Answer:
No, you cannot call a Queueable Apex job from a Future Method.
Explanation:
Future Methods are limited and cannot initiate Queueable jobs.
27. What is the purpose of the System.schedule method?
Answer:
The System.schedule method is used to schedule an Apex class to run at a specific time.
Explanation:
It takes a job name, cron expression, and an instance of the class to run.
28. Can you update the same object in a Future Method that was called from a Trigger?
Answer:
No, you cannot update the same object in a Future Method called from a trigger.
Explanation:
This avoids recursion and governor limit issues.
29. What is the maximum number of Queueable jobs that can be chained?
Answer:
The maximum is 2 Queueable jobs that can be chained.
Explanation:
This limit prevents infinite chaining and resource exhaustion.
30. What is the purpose of the Database.AllowsCallouts annotation?
Answer:
The Database.AllowsCallouts annotation allows a Future Method to make callouts to external systems.
Explanation:
Without this annotation, Future Methods cannot make callouts.
31. Can you use SOSL in Batch Apex?
Answer:
Yes, you can use SOSL in Batch Apex.
Explanation:
SOSL is useful for searching across multiple objects.
32. What is the purpose of the Database.BatchableContext object?
Answer:
The Database.BatchableContext object provides information about the Batch Apex job, such as the job ID.
Explanation:
It is used in the Start, Execute, and Finish methods.
33. Can you call a Batch Apex job from a Queueable Apex job?
Answer:
Yes, you can call a Batch Apex job from a Queueable Apex job.
Explanation:
This allows you to combine the strengths of both types of asynchronous processing.
34. What is the purpose of the System.enqueueJob method?
Answer:
The System.enqueueJob method is used to start a Queueable Apex job.
Explanation:
It adds the job to the asynchronous queue for execution.
35. Can you use DML in a Future Method?
Answer:
Yes, you can use DML in a Future Method.
Explanation:
Future Methods can perform database operations like inserts, updates, and deletes.
36. What is the purpose of the Database.Stateful interface?
Answer:
The Database.Stateful interface allows you to maintain state across batch executions in Batch Apex.
Explanation:
Without it, variables are reset after each batch.
37. Can you call a Scheduled Apex job from a Trigger?
Answer:
No, you cannot call a Scheduled Apex job directly from a trigger.
Explanation:
Scheduled Apex is designed to run at specific times, not in response to triggers.
38. What is the purpose of the Database.executeBatch method?
Answer:
The Database.executeBatch method is used to start a Batch Apex job.
Explanation:
It takes an instance of the Batch Apex class and an optional batch size.
39. Can you use SOQL in a Future Method?
Answer:
Yes, you can use SOQL in a Future Method.
Explanation:
Future Methods can query data from the database.
40. What is the purpose of the Database.Batchable interface?
Answer:
The Database.Batchable interface is used to define a Batch Apex class.
Explanation:
It requires implementing the Start, Execute, and Finish methods.
41. Can you call a Future Method from a Queueable Apex job?
Answer:
No, you cannot call a Future Method from a Queueable Apex job.
Explanation:
Future Methods are limited and cannot be called from Queueable jobs.
42. What is the purpose of the Database.QueryLocator object?
Answer:
The Database.QueryLocator object is used in the Start method of Batch Apex to retrieve records for processing.
Explanation:
It is ideal for large datasets.
43. Can you use SOSL in a Future Method?
Answer:
Yes, you can use SOSL in a Future Method.
Explanation:
SOSL is useful for searching across multiple objects.
44. What is the purpose of the Database.RaisesPlatformEvents annotation?
Answer:
The Database.RaisesPlatformEvents annotation allows a Future Method to publish platform events.
Explanation:
Platform events are used for real-time integrations.
45. Can you call a Scheduled Apex job from a Batch Apex job?
Answer:
No, you cannot call a Scheduled Apex job directly from a Batch Apex job.
Explanation:
Scheduled Apex is designed to run at specific times, not in response to Batch Apex.
46. What is the purpose of the Database.BatchableContext.getJobId method?
Answer:
The Database.BatchableContext.getJobId method returns the ID of the Batch Apex job.
Explanation:
This is useful for tracking and logging purposes.
47. Can you use DML in a Queueable Apex job?
Answer:
Yes, you can use DML in a Queueable Apex job.
Explanation:
Queueable Apex can perform database operations like inserts, updates, and deletes.
48. What is the purpose of the Database.Stateful interface in Queueable Apex?
Answer:
The Database.Stateful interface is not used in Queueable Apex.
Explanation:
Queueable Apex maintains state automatically.
49. Can you call a Batch Apex job from a Scheduled Apex job?
Answer:
Yes, you can call a Batch Apex job from a Scheduled Apex job.
Explanation:
This allows you to schedule large data processing tasks.
50. What is the purpose of the Database.AllowsCallouts annotation in Queueable Apex?
Answer:
The Database.AllowsCallouts annotation allows a Queueable Apex job to make callouts to external systems.
Explanation:
Without this annotation, Queueable Apex cannot make callouts.
Conclusion
In this second part of our series, we delved deeper into Asynchronous Apex, exploring advanced topics like Batch Apex state management, Queueable Apex chaining, and the interactions between different asynchronous processes.
These 25 questions have equipped you with a stronger understanding of how to handle complex scenarios, optimize performance, and work within Salesforce’s governor limits.
Stay tuned for Part 3, where we’ll wrap up this series with even more advanced questions and insights into Asynchronous Apex.
Keep learning and building amazing solutions on the Salesforce platform!
