Apex Record Locking

Introduction to Apex Record Locking

Apex record locking is a crucial concept when dealing with concurrent data operations in Salesforce. It ensures that multiple users or processes do not make conflicting changes to the same record. The FOR UPDATE clause is used in SOQL queries to lock a set of records, preventing others from modifying them while a transaction is ongoing.

Why Use Record Locking?

Record locking is essential in scenarios where data integrity is critical, such as financial transactions or inventory management. Without proper locking mechanisms, you might encounter issues like data inconsistency or lost updates, which can adversely affect business operations.

How Record Locking Works

In Salesforce, when a record is locked using FOR UPDATE, any subsequent transactions that attempt to modify the same record will be queued until the lock is released. This behavior ensures that only one transaction can modify a record at a time, thereby maintaining data consistency.

Using FOR UPDATE in SOQL

The FOR UPDATE keyword is appended to a SOQL query to lock the selected records. Here’s a basic example:

In this example, all Account records with the Name 'Acme' are locked. Other transactions trying to update these records will have to wait until the lock is released.

Handling Lock Exceptions

When using record locking, you may encounter QueryException if the lock cannot be obtained immediately. It's important to handle these exceptions to ensure a smooth user experience.

Best Practices for Record Locking

• Use Locks Sparingly: Lock only the records you need to update to minimize performance impact.
• Implement Retry Logic: Anticipate locking conflicts and plan for retries or user notifications.
• Monitor and Optimize: Regularly review your locking logic to ensure it meets your performance and consistency needs.