Re: MYDUL avaialbe for recovery, another choise of DUL.

Jonathan Lewis wrote:
> <fitzjarrell_at_cox.net> wrote in message
> news:1127793538.884457.114420_at_g43g2000cwa.googlegroups.com...
> >
> > AnySQL (d.c.b.a) wrote:
> >> Why I want to reverse DUL, I just wrote one of mine according to my
> >> knowledge of oracle block format. Spent a lot of time on it, illegal?
> >
> > Most certainly it is, as stated in the Oracle licence agreement:
> >
> > "(d) prohibits causing or permitting the reverse
> > engineering, disassembly or decompilation of the Program(s); ..."
> >
> > You have, in your infinite wisdom, reverse-engineered DUL. You have,
> > therefore, violated the terms of the Oracle licencing agreement and, as
> > such, are subject to prosecution.
> >
> > Have a nice day.
> >
> >
> > David Fitzjarrell
> >
>
> That introduces an interesting point for many
> of the Oracle 'gurus'. When Steve Adams
> writes something about how the redo writer
> works and how to set the best size for the
> log buffer and files, has he "caused or permitted
> the reverse engineering" of part of the code.
>
> When I describe how the hash join mechanism
> works, or how the cost based optimiser does
> its arithmetic have I done the same.
>
> When Cary Millsap explains what's in a trace
> file, and where tkprof gets it wrong, has he done
> the same.
>
> Where can you draw the line ?
>
> If someone gives you a raw datablock and says:
> The information on this block is from a
> table with N columns of types x,y, and z
> you might be able to write a program to decode
> the dump without knowing the block came from
> an Oracle database.
>
> If you then claimed you could dump the block with
> a self-consistent image of all committed changes as
> at a particular SCN, then I think you would be on
> very shaky ground, because you would have had
> to apply very detailed knowledge of the operation
> of the software that produced, and reads, the block.
>
>
> This is all just conjecture, by the way, but I can't
> help thinking that the people who explain Oracle
> internals (correctly) might technically be in breach of
> their licence agreements.
>
>
>
> --
> Regards
>
> Jonathan Lewis
>
> http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html
> Cost Based Oracle - Volume 1: Fundamentals
> On-shelf date: Nov 2005
>
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> The Co-operative Oracle Users' FAQ
>
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Thank you Jonathan for your concise thoughts on this.

I was thinking along the same lines, that the activity that many of us engage in while trying to find what makes Oracle tick could be construed as reverse engineering.

Creating 10046 and 10053 trace files could be considered reverse engineering, but it is apparently not viewed that way by Oracle.

eg. the symbols in 10046 traces are explained in a document on MetaLink, which is available to anyone with a support contract.

http://metalink.oracle.com/metalink/plsql/showdoc?db=NOT&id=39817.1

I don't know if reverse engineering a data format (such as in myDUL) is equivalent to reverse engineering software.

Many utilities exist that can read MS Office formats, some of them are open source - this seems analagous to me.

Personally I would not care to have Oracle's attorneys emailing me, and would try not to push the envelope in such endeavors.

Jared Received on Tue Sep 27 2005 - 17:54:15 CDT