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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