这两天看到的一个比较有意思的讨论是关于 MyDUL 的版权问题.MyDUL 这个工具前一段时间我介绍过.
MyDUL 的编写者 d.c.b.a 老兄在给几个 Oracle 用户成功的恢复了数据之后。似乎信心大增,觉得有必要进行一下宣传。于是乎跑到了 Google 的新闻组发了一个帖子，但他始料不及的是并没有看到好评如潮，反而招来几乎是压倒性的质疑声音，甚至包括 Jonathan Lewis 这样业界知名专家的恶评。
参与讨论的一个关键点是 d.c.b.a 的 MyDUL 是不是反向工程(Reverse Engineering).很明显，根据讨论者给出的参考,即使是 Unix 的 strings 命令严格来说都是反向工程.所以, MyDUL 是否侵犯版权似乎是明摆着的事情.
也有人反对，这样说来，创建 10046 和 10053 的 trace 文件也是反向工程(我认识的很多 dba 也热衷于研究 Oracle "internal"的dong) ? 不是也有很多工具可以读取微软的 office 文档的么? 另外有人提问说：Quest 公司的 Shareplex 也是 Illegal ? 每一条还是基本上都有解释的，比如关于 10046 跟踪文件的创建：
Such traces are provided by Oracle without the use or construction of third-party tools. As you've stated the explanation of the trace symbols is provided by Oracle Corporation; Oracle provides these traces to enable a DBA to properly tune queries and the database. This, in my mind, is a far different situation than knowingly writing a replacement, albeit incomplete, of DUL.
不过，接下来 d.c.b.a 的发言似乎是不打自招：
I wrote a tool to do os dump of binary file, just like od, and the I issue the "alter system dump datafile ..." command, then compair and found the location, after multiple times, I can locate the most of key bytes in block, Oracle should use a relative simple rule to format block to keep high effectivity, so after tried many times I found out some rules.
两点思考:
- 有的时候，还是闷声发大财为好......
- Steve Adams 这样的高手为什么不自己写一个类似 DUL 的工具出来?
其实也未必要高手才可以写出类似于dul的工具啊,
偶觉得没有什么难的技术.
问题是：为什么高手不写? 不要跑题
我觉得是高手忙着赚单子，没时间写:)
我觉得Steve Adams忙着接单赚钱，没有时间写:)
可能他们不屑一顾，不清楚:)
I can give a vivid example, happened in SV of USA of course:
two chinese guy jumped out from their previous working IT company and start their own business. They run it very successful and make themselves millionaire. Unfortunately, in their own IT product, they use similar technique and some base code from their previous company. At the beginning, everybody knows that but they simply ignored it. But after it is well-known, tradegy follows up. The previous company sued these two guys for illegal usage of product, it is against patent law,blah,blah,blah,etc...
Result:
two smart chinese guys were all sent to prison.
every single penny they made, have to be paid to their previous company.
business went bankrupt.
Every company,person knows how important to protect their own product, invention, idea. In China, it is not feasible,yet. but I believe somehow,it is going to be a global issue. we think chinese people are smart, it is not true in western logic thinking. Maybe I am a bit pessimistic.
netbanker is right
the idea of the law and the business is not the same.
至少我没有抄什么base code. 不知道这一点对于结果有何影响.