等待事件：kksfbc child completion

等待事件：kksfbc child completion

大家好，遇到了一个等待事件：kksfbc child completion，持有该等待事件的os process占据较高的CPU资源，后来没有办法就强制将这两个问题会话给Kill掉了，问题也就解决了，但是我对这个等待事件的理解还是不很清楚。

metalink上说是bug 8575528，需要打上patch 8575528，并修改参数_cursor_features_enabled=10.

如下是matalink的描述：

This fix has been superseded by bug:8575528.

A session may go into an infinite spin just after a wait
for 'kksfbc child completion'. The spin occurs with
a stack including kksSearchChildList -> kkshgnc where
kksSearchChildList loops forever.

This problem can also lead to internal error such as any of
ORA-600 [kksSearchChildList1], ORA-600 [kksSearchChildList2]
ORA-600 [kksSearchChildList3], ORA-600 [kkshgnc-nextchild]

Or Trace dumps on kksSearchChildList4 .

Note:
  This fix is disabled by default in 10g.
  To enable this fix you must explicitly set the following
  parameter for instance startup:
    "_cursor_features_enabled" = 10

bug,
原因是在hard parse时出错，建议在os级别kill process