Re: RM and abstract syntax trees

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sun, 11 Nov 2007 10:40:23 -0400
Message-ID: <47371464$0$5301$9a566e8b@news.aliant.net>

David Cressey wrote:

> "Bob Badour" <bbadour_at_pei.sympatico.ca> wrote in message
> news:47361e66$0$5287$9a566e8b_at_news.aliant.net...
>

>>David Cressey wrote:

>
> [snip]
>

>>I would argue that an OID is nothing more than an abstract address. The
>>problem with OIDs are people use them to point at things. The first and
>>most compelling indication of this is when they mention some alleged
>>performance advantage.

>
> Agreed. However, the fact that people use them to point at things doesn't
> mean that they really are pointers.

I disagree. If they are used to point, they are pointers. What the heck do you think the word means?

>>>In most pointer based systems,  the pointer is not included in the

>
> contents,
>

>>>being seen as redundant to its location.
>>>
>>>The distinction between content based addressing and pointer based
>>>addressing is fundamental to the comparison of databases built on the
>>>relational model and databases built on the graph model.
>>
>>The products that used OIDs generally used them as pointers.

>
> See above.
>
>

>>>It is possible,  by suitable abstraction and by poor design choices, to
>>>create a database that offers none of the advantages claimed for the
>>>relational model,  while appearing to conform to the relational model
>>>superficially.   Sad to say,  thousands of such databases have been
>>>constructed over the years,  and have led many uneducated database

>
> newbies
>

>>>to believe that the relational model doesn't really offer the advantages
>>>that its proponents cliam.
>>
>>Hear! Hear!

>
>
> Thanks. This is the point that we have got to get across, for as long as
> it takes.
>
> What I'd like to be able to do is to point newbies at successful designs.
> However, this sometimes leads people to believe that a successful design
> for a slightly different problem is going to serve them well.

Every design involves tradeoffs, which makes it impossible to arrive at an objective measure for success. Every tradeoff opens the door for someone to say: "If you had done this differently, you would be able to do this other thing much more easily." Received on Sun Nov 11 2007 - 08:40:23 CST