Re: The IDS, the EDS and the DBMS
Date: Wed, 08 Sep 2004 00:32:56 +0200
Message-ID: <413e371d$0$43451$e4fe514c_at_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 out of date.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 Outdated? Not my impression - but maybe I am getting outdated.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 Wed Sep 08 2004 - 00:32:56 CEST