From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,bf02c238a92156a3 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news1.google.com!fu-berlin.de!uni-berlin.de!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Windows Ada database support. Date: Tue, 30 Nov 2004 19:52:16 +0100 Organization: cbb software GmbH Message-ID: References: <5e3e03a7.0411240431.7e037a4e@posting.google.com> <17w0jtt2xq2ya.1nj2623n37457.dlg@40tude.net> <1ohmhrsp481iu.w61dt6dz9cqk$.dlg@40tude.net> <1cxufyzpjc6ns.1lomm6dpfxyhb$.dlg@40tude.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Trace: news.uni-berlin.de FZp7EyDXZUZXAT0WvrKFUA4BSMdfBi67EBkDt0wnofUu589ZE= User-Agent: 40tude_Dialog/2.0.12.1 Xref: g2news1.google.com comp.lang.ada:6676 Date: 2004-11-30T19:52:16+01:00 List-Id: On Tue, 30 Nov 2004 16:07:06 +0000 (UTC), Georg Bauhaus wrote: > Dmitry A. Kazakov wrote: >: On Mon, 29 Nov 2004 22:05:50 +0000 (UTC), Georg Bauhaus wrote: >:>:> See also Frank Piron's comment about implicit cursors in >:>:> PL/SQL. >:> >:> Wrong abstractions in PL/SQL too? >: >: Is in your opinion PL/SQL better than Ada? > > PL/SQL has a specific purpose, and a rich set of facilities for handling > relations. 1. Why relations should be handled? 2. Why Ada cannot handle them? > I don't see why anyone using an Oracle DB would want to write > stored procedures in Ada? Fair enough. Compare: "I don't see why anybody using C would want to switch to Ada". Indeed, they don't. >:>:>: So what? As long as my application uses Ada.Database, I do not care. >:> >:> Is this a motto? >: >: As long as the goal is to have a generic data base interface. > > Well, the prime goal for me has got to be an application that works > within the limits set by the RDBMS, in this case Oracle. If I have > to "descend" to sequential access or to random access via cursors, > so be it. You could simply say: we need no generic data base interface. >: It is difficult to develop something >: large, complex and concurrent using only arrays. As a matter of fact. > > Say that to someone you uses one of the array programming languages... > > SQL is much more than just arrays. It also has sets and tables and > cursors. Like Ada 2005. > > Indeed RDBMSs have some low level features, but why not? There are > DBs based on different data structures, like extensible types. > Nice as they are, they do have real time limits, as a matter of fact. So the point is: "real-time constraints cannot be met if data structures are extensible"? > And they do not always match the types of application data, which > can be of a rather fixed shape. Why? From my experience, there was no single case, when our customer didn't ask for an extensible data model [and was told that he/she cannot afford it]. Sooner or later they will break the wall. >: The same way we program concurrent distributed applications in Ada! > > And you know what people say about task switching? Rendevous has > its temporal aspects, how do you abstract them away? I wouldn't. But it is perfectly possible. In C, which has no tasks, an entry is replaced by a procedure with an additional parameter TimeOut. > There are > others who want to use the database, too, so "could you please stop > shaking hands and give us some of the resources back if you don't > need them any longer!" I do not see why exposing, say, tasks should be less effective than hiding them into connections, transactions whatsoever. Basically I am unable to see any crucial difference between a data base engine or embedded controller or JVM. Tell me 1. Why Ada cannot be targeted there? 2. Why Ada will be less efficient than SQL? >: ADT, OO, and so get rid of raw table views. Especially because there might >: be data bases for which table views could be very inefficient. > > I'd leave RDBs only when table views are a burden, not because there > might be cases. OK, in data acquisition it is a heavy burden. Customers wish a table (equidistant time, value1, value2 etc). But the system is event/data driven. So the table basically contains useless garbage. Yet they still want it, because tables are so cool. >: Just look how many DB programmer positions are >: offered. This is a significant indicator, that the technology is outdated. > > For me the number of database adminstrators/programmers has to do > with the number of significant installations and the number of > projects. > This number depends on the number of organisations, and on their > willingness/ability to invest. I don't think that the number of > wealthy organisations will change significantly because some > programming techniques evolve. They will invest in other things. Nowadays, nobody invests in chopping firewood... >:> What has Ada versus Assembly got to do with resource consumption of >:> communicating programs (Ada program <-> database program?) >: >: It is because you present performance as an argument for using a low level >: mechanism. > > I present resource consumption as a real time constraint > on the structure of data and on techniques of data access. But you do not explain why SELECT * is less resource consuming than anything else. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de