Scenario: You are leading the database testing process for a new e-commerce platform. During testing, you encounter a discrepancy between the expected and actual results of a complex SQL query. What should be your immediate action?

When encountering discrepancies in SQL query results, the immediate action should be to examine the query execution plan and indexes. This helps in identifying any performance bottlenecks, such as missing or inefficient indexes, which may cause unexpected results. Analyzing the query execution plan provides insights into how the database engine processes the query, aiding in optimization efforts.