What will happen if you set the parameter OPTIMIZER_IGNORE_HINTS to TRUE?

Setting the parameter OPTIMIZER_IGNORE_HINTS to TRUE instructs the Oracle database optimizer to disregard any hints that may have been provided in SQL statements. Hints are special directives included in SQL queries to influence the optimizer’s choice of execution plans. When this parameter is set to TRUE, the optimizer does not use those hints, allowing it to make decisions based solely on its own algorithms and statistics, rather than potentially suboptimal human-provided advice.

This setting can be particularly useful in scenarios where you want the optimizer to operate without the constraints of hints—essentially letting the optimizer do its job based on the most current understanding of data distribution and available resources. This allows for flexibility and adaptability, especially in dynamic environments where the optimal query plan may change over time.

In contrast, when hints are honored, the optimizer might follow specific suggestions that could lead to suboptimal performance if the underlying data characteristics have changed. Therefore, the option to ignore hints can sometimes lead to better performance, as the optimizer can analyze the execution plan purely based on the latest data statistics.

The other options do not relate to the function of the OPTIMIZER_IGNORE_HINTS parameter and its primary focus on the handling of hints during SQL processing. Redaction policies and performance statistics are unrelated