Oracle的to_date转换可能导致的错误SQL结果

David.Guo同学遇到了如下一个Bug，以前也遇到过，今个转录一下了。
David的图说明了所有问题，看似毫无问题的一个查询出现了错误的结果：

其实可以看看执行计划的谓词转换，看看具体问题的出现原因。

Metalink上的Bug 4156916 - Dump / wrong results from TO_DATE without a full date format mask 可能与此有关。

这个BUG的内容记录是：

Description

Wrong results or dumps possible from queries having
predicates using TO_DATE (explicit or implicit) without 
a full date format mask.


Workaround:
  Set the following two events
   event 38055 level 1 (disable redundant range predicate removal)
   event 10078 level 1 (disable removal of constant predicates)

通过Event 38055 和 10078 可以实现Workaround。
这个Bug的影响范围和修复版本如下：
Affects:

Product (Component) Oracle Server (Rdbms)

Range of versions believed to be affected Versions < 10.2

Versions confirmed as being affected
9.2.0.6

Platforms affected Generic (all / most platforms affected)

Fixed:

This issue is fixed in
9.2.0.7 (Server Patch Set)
10.1.0.5 (Server Patch Set)
10.2.0.1 (Base Release)

参考Metalink文档ID：4156916.8。

David的链接： http://www.oracledba.com.cn/blog/archives/463

*Product (Component)*	Oracle Server (Rdbms)
*Range of versions believed* to be affected**	Versions < 10.2
*Versions confirmed* as being affected**	9.2.0.6
Platforms affected	Generic (all / most platforms affected)

Description

Affects:

Fixed:

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