关于Unspecified Wait Event这个bug

数据库升级到11.1.0.7.0之后，出来了一大堆的bug，别问我 为什么不升级到11gR2

我这里遇到个 unspecified wait event 。Metalink 文档描述如下：

"Unspecified Wait Event" After Installing 9352179 - 11.1.0.7.3 Patch Set Update [ID 1107783.1]
		修改时间 24-JUN-2010类型 HOWTO状态 PUBLISHED

In this Document
Goal
Solution
References

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Applies to:

Oracle Server - Enterprise Edition - Version: 11.1.0.7 and later[Release: 11.1 and later ]
Information in this document applies to any platform.

Goal

Explain why after installing 9352179 - 11.1.0.7.3 Patch Set Update, the wait event "unspecified wait event" is being reported on ASH reports and on Top Activity DB Console screen?

Solution

The "unspecified wait event" is introduced by the backport of Bug 7510766 which is included in the 11.1.0.7.3 Patch Set Update. The wait is indicative of an earlier un-tracked IO wait. The backport makes the wait visible and thus improves the db time calculation in AWR reporting. Having this wait in an AWR report after applying the backport is NOT a performance or correctness issue. As per the above comment, this backport has introduced a change which now externalizes a previously un-tracked I/O wait. The wait was always there, just never previously externalized. It can be safely ignored.

References

BUG:7510766 - RESOURCE MANAGER IS OVER THROTTLING
BUG:8660422 - SINCE APPLYING PATCH FOR 8624887 "UNSPECIFIED WAIT EVENT" IS SEEN IN AWR
BUG:9059264 - LGWR WAITING FOR "UNSPECIFIED WAIT EVENT"

Oracle太了，他居然说The wait was always there, just never previously externalized. It can be safely ignored.

自从出现了unspecified wait event， 我就再也没在数据库中看到db file scattered read,db file sequential read

我怀疑 unspecified wait event已经把 这2个等待事件给 xxoo了 奶奶的，给 调优工作带来巨大不便