Another optimization technique is to use query hints, such as INDEX or FORCE ORDER, to guide the query optimizer's execution plan. However, caution should be exercised when using query hints, as they may not always lead to the desired results and can hinder flexibility in adapting to changing data or schema.

In some cases, denormalizing tables by duplicating data can also be considered for query optimization purposes. This reduces the need for complex joins and can improve query performance. However, denormalization should be carefully planned and implemented, as it can introduce data redundancy and potential update anomalies.

One approach to optimize complex queries involving multiple tables is to properly index the tables. By creating appropriate indexes on frequently used columns, the query optimizer can quickly locate relevant data. Additionally, breaking down complex queries into smaller, more manageable subqueries can also improve performance.