Information about Batch Apex on the Salesfroce.com platform. Presented at the Chicago Salesforce Developer Group on June 2nd, 2015.

1. Batch Apex
Dave Helgerson
davehelgerson.com
@davehelgerson

2. Batch Apex Agenda
• High level description of Batch Apex
• How to use Batch Apex
• Simple Code Examples
• Demos in a Salesforce org
• Questions

3. What is Batch Apex?
• Batch Apex is a way to process millions of
records on the Salesforce platform

4. How does Batch Apex work?
• Start by defining a dataset to process through
– Database.QueryLocator
– Custom Iterator
– List Collection

5. How does Batch Apex work? (cont.)
• Then, the dataset is divided into smaller
chunks of records
– Each chunk of dataset processes as a separate
transaction
– Size of each chunk is defined when submitting the
Batch process

6. How does Batch Apex work? (cont.)
• Finally, after all chunks of the dataset have
been processed, post processing can be run
– Send Emails
– Update aggregate totals

7. How does Batch Apex work? (cont.)
• Define the dataset
• Divide and process
• Post processing

8. How does Batch Apex run?
• Asynchronously, of course!
• Like @future methods or Queueable Apex

9. What conditions are ideal for Batch
Apex?
• Tasks that involve large datasets or are
processing intensive
• Source of data is from a single database
object, and Dataset can be retrieved with a
single SOQL statement
• Each unit of work is independent
• Not time-critical

10. Give me scenarios for Batch Apex
processing
• Record Ownership Reassignment
• Data Retention
• Data Cleansing
• Recalculating Apex Managed Sharing
• Other Mass Record Update

11. What does the code look like?
• Class definition implements the
Database.Batchable interface
• Three methods are required
– start()
– execute()
– finally()

12. What does the code look like? (cont.)
• QueryLocator Example

13. What does the code look like? (cont.)
• List Example

14. What does the code look like? (cont.)
• Iterable Example

15. What does the code look like? (cont.)
• Additional Class Attributes
– Database.AllowsCallouts
• 100 callouts per transaction (Winter ’15)
– Database.Stateful
• State is maintained between transactions
• Instance member variables retain their values
• Static member variables are reset
– Scheduable
• Combine the scheduling class with the Batch Apex class
• global void execute(SchedulableContext sc){

16. How do I run a job?
• Batch Apex is invoked programmatically with
Database.executeBatch or
System.scheduleBatch
– Visualforce page controller
– Apex trigger
– Ajax Toolkit
– Execute Anonymous from Force.com IDE or
Developer Console
– Scheduled Job

17. How do I run a job? (cont.)
• Database.executeBatch
– Submits a job to the queue
– Parameters:
• Instance of the class
• Scope (optional)
– Example:
• Database.executeBatch(new ExampleBatch(),
100);

18. How do I run a job? (cont.)
• System.scheduleBatch
– Creates a scheduled job
– Parameters:
• Instance of the class
• Job name
• Time interval, in minutes, after which the job should start
executing
• Scope (optional)
– Example:
• System.scheduleBatch(new ExampleBatch(),
'Test', 5, 100);

19. How do I run a job? (cont.)
• Job is submitted to the queue
– 5 jobs can be processing at once
– 100 jobs can be in the queue at once.
• Flex Queue (Spring ‘15)
• Enable in the “Apex Flex Queue” in Critical Updates
• Job Id is returned
– Track progress by the job Id

20. How do I schedule a job?
• Scheduling from the UI
– Setup -> Develop -> Apex Classes -> Schedule Apex button

21. How do I schedule a job? (cont.)
• Scheduling in Apex
• system.schedule()
• Name
• Cron expression
• Instance of Schedulable class
• Example:
– system.schedule('My Scheduled Job',
'0 15 * * * ?', new ExampleSchedulable());

22. How do I monitor a job?
• Setup -> Monitor -> Jobs -> Apex Jobs
• Shows active and completed job information

23. How do I monitor a job? (cont.)
• AsyncApexJob
– Accessible in Apex

24. How do I test Batch Apex?
• Use Test.startTest() and Test.endTest()
• Asynchronous processes run synchronously
when the Test.endTest() command executes
• The execute() method may only be invoked
once

25. How do I test Batch Apex?

26. Considerations Summary
• QueryLocator - maximum of 50m records
• Custom Iterators - maximum of 50k records
• Governor limits apply to each invocation of
the execute method()
• @future methods cannot be called
• Timing is determined by Salesforce
• 5 concurrent jobs can process at once
• 100 jobs can be in the queue

27. Demo
• Submitting
• Scheduling
• Monitoring

28. Questions?
davehelgerson.com
@davehelgerson