Re: Windows Ada database support.

[Georg Bauhaus <sb463ba@l1-hrz.uni-duisburg.de>]

Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
: On Mon, 29 Nov 2004 14:07:45 +0000 (UTC), Georg Bauhaus wrote:

:> This is interfacing to "world", not to some abstraction.
 
: Which only supports the point that cursor might be wrong abstraction.

Aha.

Cursors are not an abstraction from the point of view of an Ada
program.  SQL Cursors are a given part of the "world", in this case, the
data base system.  Go argue with Oracle Corp.


:>   See also Frank Piron's comment about implicit cursors in
:> PL/SQL.

Wrong abstractions in PL/SQL too?


:>: So what? As long as my application uses Ada.Database, I do not care.

Is this a motto?


:> Thick abstractions leave some choices behind. This isn't always helpful.
 
: Surely, but statistically irrelevant.

Aha. But allow me to say, as much as I'd wish to be able to use
a nice transparent, almost invisible interface to database system,
I see no base in reality for saying that abstraction thickness is
statistically irrelevant. For several reasons, and also because

- cursors do occur, no matter whether you express them behind Ada
  abstractions or not. Working with snapshots affects performance/
  shared resources to the point where you can no longer hide them relying
  on some AI system to free the resources automatically so the system
  keeps running.

  Working with RDBMSs means to have influence on another program's
  multiply shared data in soft real time! However, your program doesn't
  control that other program, your program must be well-behaved. Show me
  how to do this in some Ada.Databases.

- saying that performance/resources in database systems are statistically
  irrelevant makes me think that your perspective on DBs is different
  from mine, and probably not just mine ;-)

: Otherwise we would have no Ada and still were programming in assembly.

What has Ada versus Assembly got to do with resource consumption of
communicating programs (Ada program <-> database program?)
Other than trying a rhetorical trick to support a notion of statistical
irrelevance of SQL cursors in RDBMS? ;-)


-- Georg Bauhaus