Re: The IDS, the EDS and the DBMS

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Wed, 08 Sep 2004 00:32:56 +0200
Message-ID: <413e371d$0$43451$e4fe514c@news.xs4all.nl>

Laconic2 wrote:

> mAsterdam wrote:

>>>>Persistence is sharing data between multiple subsequent
>>>>instances of the same program.
>>>>Concurrency control and shared access solve the
>>>>problems of sharing data between multiple simultane
>>>>instances of the same program.
>>>>Metadata comes into play when data is shared between
>>>>really different programs. *Really* different as in not
>>>>sharing the same code.
>>>
>>>Agreed.
>>>
>>>I might want to rephrase "the same program"  as 
>>>"objects of the same class".
>>>But I'm not sure of this.
>>
>>I wasn't when trying to formulate this.
>>In this case "objects of the same class" opens up a
>>can of irrelevant watchameanbyzats, so I settled
>>for "program".

>
> Fair enough. In my own mind, I still think of "multiple successive
> instances of the same process", "multiple concurrent instances of the same
> process", and "multiple distinct processes". But this terminology is way
> out of date.

Old, yes. Outdated? Not my impression - but maybe I am getting outdated.

> I think I walked into the watchameanbyzats somewhat deliberately, when I
> chose the word "encapsulated" for the EDS. The reason I choose "objects"
> for the "unit of interaction with the database" is that object oriented
> people are oriented towards... well... "objects".
>
> And, very specifically, there was a conversation in here a few months ago
> in which an OO person challenged the necessity of having the database
> metadata describe the data by saying something along the lines of, "if we
> hide the metadata inside the object class, it doesn't need to be in the
> database." That may not be the exact wording used, but it's close.
>

>>I'll abuse this to introduce one thing as if I had
>>thought of it originally (well I did, honestly, but I
>>forgot to write it down): shared access is (possibly)
>>sharing from different locations.
>>
>>Somebody now may wrap this up into a nice article about
>>levels of data sharing, prerequisites and implications :-)

>
> I would like the nice article to at least reference the classic works on
> "semaphores", "race conditions", and "concurrency".
> No sense reinventing the wheel, unless it's really a new wheel.

These all address the lighter sharing levels. Maybe the article should reference classic works on "meaning" for the heavy stuff - now there's an old wheel :-) Received on Tue Sep 07 2004 - 17:32:56 CDT