MOS上的，抄袭一下：

1. For potential workaround, set following parameter:

alter system set "_optimizer_adaptive_plans"=false;

2. Download and apply Patch 16589794 for the version and platform where the issue is observed.

3. The bug is fixed in 12.1.0.2 or later.

 你数据库版本正好是12.1.0.1