Hashing for CDC

Problem

You are implementing a Change Data Capture (CDC) system. Comparing 50 columns to see if a row was updated is very slow. Instead, you create a checksum of the entire row. Select first_name, last_name, and create a hash of the two columns combined to detect changes. Use the md5() function.

Database Schema

Table: employees

• employee_id (INT): Unique identifier for the employee.
• first_name (VARCHAR): First name of the employee.
• last_name (VARCHAR): Last name of the employee.
• salary (INT): Employee's salary.
• department_id (INT): Foreign key referencing the department.
• manager_id (INT): Foreign key referencing the manager (another employee).
• hire_date (DATE): Date the employee was hired.

Table: departments

• department_id (INT): Unique identifier for the department.
• department_name (VARCHAR): Name of the department.

Try It

Hint

Solution