参考了这篇文章 http://space.itpub.net/15415488/viewspace-621535,做了下面的调整,关闭11G新特性ACS,
ALTER SYSTEM SET _optimizer_extended_cursor_sharing_rel='NONE' SCOPE=BOTH;
ALTER SYSTEM SET _optimizer_extended_cursor_sharing='NONE' SCOPE=BOTH;
ALTER SYSTEM SET _optimizer_adaptive_cursor_sharing=FALSE SCOPE=BOTH;
好像确实有效果,12点重启后,现在的child cursors最多才5。