Scenario: A developer is tasked with optimizing the performance of a complex query involving multiple joins on large tables. Suggest how creating appropriate indexes can improve query performance in this situation.

Creating appropriate indexes for a complex query involving multiple joins on large tables can significantly improve performance. Indexes reduce disk I/O and speed up data retrieval by providing direct access paths to the rows in the tables. This eliminates the need for full table scans and allows the database engine to quickly locate the relevant rows. Additionally, indexes enhance data organization and storage by physically sorting the rows based on the indexed columns, making it easier to retrieve data efficiently. This optimization also reduces contention and improves concurrency by enabling multiple transactions to access the same data simultaneously without blocking each other. Furthermore, indexes contribute to data integrity and consistency by enforcing constraints on the indexed columns, ensuring that only valid and consistent data is stored.