Preventing Data Conflicts with Optimistic Concurrency Control

Optimistic Concurrency Control

Write a SQL script to implement optimistic concurrency control.

Solution:

-- Add a version column to the table.
ALTER TABLE Products ADD Version INT DEFAULT 0;

-- Update with version check.
UPDATE Products
SET Price = 100, Version = Version + 1
WHERE ProductID = 1 AND Version = @CurrentVersion;

Explanation:

• Purpose of the Query :
• The goal is to demonstrate how optimistic concurrency control prevents overwriting changes made by other users.
• Key Components :
• Version column: Tracks row versions.
• Conditional update: Ensures updates only succeed if the version matches.
• Why use Optimistic Concurrency? :
• Reduces locking overhead in low-conflict scenarios.
• Real-World Application :
• Useful in collaborative editing systems.

Additional Notes:

• Optimistic concurrency control is ideal for low-conflict scenarios where locks would unnecessarily reduce performance.
• Ensure that all applications accessing the database respect the versioning mechanism to avoid data corruption.
• Test thoroughly to ensure that race conditions are properly handled.

For more Practice: Solve these Related Problems:

• Write a SQL query to implement optimistic concurrency control using a version column to prevent overwriting changes made by other users.
• Write a SQL query to test the behavior of optimistic concurrency control in a collaborative editing system.
• Write a SQL query to handle race conditions using optimistic concurrency control in a low-conflict scenario.
• Write a SQL query to compare the performance of optimistic concurrency control versus pessimistic locking in a database system.

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