Re: Object-relational impedence

Brian Selzer wrote:
> "S Perryman" <q_at_q.com> wrote in message news:frot80$5k7$1_at_aioe.org...
> > Eric wrote:
> >
> >> On 2008-03-17, S Perryman <q_at_q.com> wrote:
> >
> > SP>For the real-world systems involving "variant records" that I have
> > worked
> > SP>on (100+ different record types, 100+ different property types) your
> > table
> > SP>is merely a global variable from hell (as evidenced by the several
> > telecoms
> > SP>systems that used the same approach in the 1990s and ended up being a
> > SP>lifetime rewrite and rebuild job whenever types and properties came and
> > SP>went) .
> >
> > E>If you build a system around something like that, you are crazy.
> >
> >>>How *dare* you criticise the mighty "table-oriented" programming !!?? :-)
> >
> >> I don't know what table-oriented programming is, unless you want to
> >> bring up something like Filetab. Any tool can be misused, and this case
> >> certainly sound like extreme misuse (of just about anything).
> >
> >
> > E>If it is a given that you have to deal with, all you can do is treat it
> > as
> > E>messages and parse them to put the information you need into sensible
> > E>structures. This is probably true for a much smaller number of variants.
> >
> >>>The system was just a nightmare (C, Oracle etc) .
> >>>A relational *data* base was completely the wrong impl technology for the
> >>>problem.
> >
> >>>And the developers could not be blamed for anything that they wrote (I
> >>>saw
> >>>the code) .
> >
> >> That just means that their idea of how to program with an RDBMS was
> >> similar to yours. Maybe you and they are both wrong.
> >
> > Maybe they and I were in fact right.
> >
> >
> >>>Their DB schema was normalised etc as expected (each type had a set of
> >>>attribute properties, those properties could be sets, sequences, record
> >>>types, collections of refs to instances of other types etc) .
> >
> >> Sounds like an EntityAttributeValue system - we _know_ that they are
> >> silly.
> >
> > Feel free to search on "OSI network management" , "CMIS" etc.
> > That will tell you sufficient about the subject domain for which they
> > were using an RDBMS as an impl technology.
> >
> >
> >>>The performance of the system (meta-type checking, property id retrieval,
> >>>retrieving messages from real equipment and putting property info into
> >>>the
> >>>correct tables etc) was just dire as a result of the operational
> >>>sequence.
> >
> >>>And this was for a system that only represented a manager-side view of
> >>>a network of a few hundred equipment instances. If this approach had been
> >>>used for subsequent systems I worked on (the equipment-side view, for a
> >>>network of *500,000* telephone lines) , the developers would have been
> >>>shot.
> >
> >>>It was such dis-crediting of RDBMS at the time (1991-1995) that led to
> >>>the
> >>>rise of OODBMS in the telecoms arena (at that time OODBs only had a foot-
> >>>hold in the CAD/CAM arena) . The performance difference was orders of
> >>>magnitudes.
> >
> >> Somebody designed and built a bad system, so you blame the tools they
> >> used. Oh, no, hang on, you just blamed one of the tools. All the other
> >> tools and platforms, all the designers and programmers, they were
> >> perfect.
> >
> > What are you on about ?? What *other* "tools and platforms" ??
> >
> > Their system used an RDBMS. And it performed poorly.
> > The same systems subsequently built on the same platforms (HW, OS, comms,
> > prog langs etc) , but using an OODBMS instead, performed orders of
> > magnitude better.
> >
> > That's life.
> >
>
> Funny, but this "orders of magnitude better" claim sounds like something a
> shifty politician like Barack Hussein Obama would say. He can supposedly
> turn a whole lot of nothing into something that makes women swoon.
> Politicians--especially Dimocrats, but not exclusively--play on the
> ignorance of their constituents by telling only part of the story.

Uh uh politics!

We need somebody like G.W.Bush to set everything right and give us the full story {cough} {cough} {cough}.

> Take for
> example the hysteria over global warming. The disasters and horrors that
> are predicted by the left-wing lunatics can only happen if the globe warms
> by at least 5 or 6 degrees, but in the last 100 years, the globe has only
> warmed by about half a degree.

Yeah, let the kids worry about floods and drought; we'll be dead by then. Typical repub: dump problem on the next generation (debt., climate, good-will, etc.)

> I once altered a system that was designed to
> process only 14,000 transactions per hour so that it could process ten times
> that in the same time. That's orders of magnitude improvement, but I didn't
> change the DBMS, I rewrote some poorly written procs. I once altered a
> system that had a job that was taking over 25 hours to process so that it
> took less than 30 minutes by simply adjusting the way the hardware was used.
> Again the orders of magnitude improvement was not due to changing the DBMS,
> it was making the best use of the available hardware. It is also often the
> case that you can obtain orders of magnitude performance improvement by
> simply adding an index--at least for queries that can take advantage of the
> index. Your claims of orders of magnitude better performance, therefore,
> are much like the claims of a used car salesman, or of a sleazy lawyer.
> Suspect.
>
> >
> >> Does that sound even remotely sensible?
> >
> > 1. Sounds like the rantings of someone who cannot face the possibility
> > that their pet thing was a problem.
> >
> > 2. So no, not sensible.
> >
> >
> >> I think they misused the tool.
> >
> > The reality being that they did not.
> >
> >
> >> You may say they used the wrong tool - for this particular job.
> >
> > They were constrained to use the wrong tool for the job.
> > By their employer, and by no alternative commercial technology (OODBs
> > etc) available at that time.
> >
> >
> >> Even if they did, that does not make it a bad tool.
> >
> > No one said it was.
> >
> >
> >>>What is required to get both, and the reasons why we haven't to date,
> >>>have been (for a few here anyway) discussed as per the thread subject
> >>>line.
> >
> >> It seems that a lot of the "discussions" have been people talking past
> >> one another because they have different frames of reference.
> >
> > Probably.
> > Fortunately there have been sufficient people to cogently debate with me.
> >
> >
> > Regards,
> > Steven Perryman
Received on Wed Mar 19 2008 - 04:58:40 CET