I wrote a piece of SQL for a long time before, and I was prompted by a colleague that there was a problem. I quickly found a solution online that is to run a piece of SQL.
alter system set "_optimizer_cost_based_transformation"=offIt works perfectly after running. But we can solve the problem if we can't solve it, and we need to understand the causes and consequences of the problem to avoid recurring.
It is an internal error. _optimizer_cost_based_transformation is a parameter that affects the optimizer. What is the specific meaning of this parameter? What are the different consequences of setting different states? I did not find the answer to these two questions-. -