thanks Martijn
-----Original Message-----
From: Martijn Tonies [mailto:m.tonies@...]
Sent: Wednesday, 28 August 2002 21:59
To: ib-support@yahoogroups.com
Subject: Re: [ib-support] Re: Helen: Low Selectivity Problem


I do not want to start anything that resembles flaming on the subject...

but -- read a book, ANY book written by Fabian Pascal.

I can recommend "Practical Issues in Database Management - A
Reference for the Thinking Practitioner".

See www.dbdebunk.com for more on design, RI, constraints, triggers
and much, much more...

Martijn Tonies
InterBase Workbench - the developer tool for InterBase and Firebird
http://www.interbaseworkbench.com

Upscene Productions
http://www.upscene.com

"This is an object-oriented system.
If we change anything, the users object."

> Quote: "Validating these rules in client applications is not the

bulletproof

> solution because people might be able to use a third party tool to

insert,

> delete or update data."
> This is the only reason Claudio offers as to why clients are not a good

way

> to maintain RI.
> "might" is a good choice of words here.... and in many cases the odds of

a

> "rogue" use of client tools is so small as not to even mention.
> I don't necessarily argue against his assertions but since there are no

laws

> here other than what works and doesn't work with the DB engine ....e.g.

the

> non or wring use of SUSPEND or EXIT may result in erroneous selects, but

the

> non-use of FK constraints does not invalidate a database per se. I can

and

> have, gone thru my databases at times and applied constraints where they
> apply. The performance has not suffered, and the data is no more valid

(even

> after several years) than it was before the contraints were present.

What

> does this say? And yet with the FK constraints in place, I have still
> managed to manually destroy some sections of data during trials of

client

> upgrades, while still not colliding with an constraint

exception...(thank

> god for test databases).
>
> Believe it not.. I do not modify my delphi application source to the
> following:
> Application.CreateForm(TMain, Main);
> try
> Application.Run;
> except
> .......
> maybe I should
>
> all good fun eh?
> Alan
> -----Original Message-----
> From: Ales Kahanek [mailto:ales.kahanek@...]
> Sent: Wednesday, 28 August 2002 21:04
> To: 'ib-support@yahoogroups.com'
> Subject: RE: [ib-support] Re: Helen: Low Selectivity Problem
>
>
> The article from Claudio is on my opinion one big recommendation to

use
FK

> constraints ...
> Ales
>
> > -----Original Message-----
> > From: Frank Ingermann [mailto:frank@...]
> > Sent: Tuesday, August 27, 2002 12:18 PM
> > To: ib-support@yahoogroups.com
> > Subject: Re: [ib-support] Re: Helen: Low Selectivity Problem
> >
> >
> > Hi Ryan,
> >
> > Scronkey wrote:
> > > --- In ib-support@y..., "Alan McDonald" <alan@m...> wrote:
> > >
> > >>I might jump in here...
> > >>I do not use foreign keys at all in my databases!
> > >>ooooh I hear frowns and tisk tisks here....
> > >>but nonetheless, my triggers do all the work for me. They also
> > >>provide a far more comfortable environment to develop in.
> > >>
> > >>Alan
> > >>
> > >
> > >
> > > Could you possibly point me to some info regarding triggers and

RI?

> > > I'm quite new to FB / triggers / sp's
> > > I will research CREATE EXCEPTION like Helen suggested.
> > >
> > > Rgds,
> > > -Ryan
> >
> > this might be something for you: Claudio V.'s article on
> > "Declarative referential integrity v/s triggers"
> > http://www.cvalde.com/document/declaRefIntegVsTrig.htm
> >
> > it explains some important issues to keep in mind when doing
> > RI "by hand". what
> > it doesn't have is example triggers - in case you get stuck,
> > just keep asking :-)
> >
> > (i'm doing RI by hand because a) nothing ever gets deleted in
> > my gdb and b) all
> > relations/joins go via surrogate keys, so what's left of RI
> > is so little that it
> > is easier done with triggers *in my case*...)
> >
> > regards & hth,
> > fingerman
> > --
> > --------------------------------------------------------------
> > -----------
> > when parsers parse, and compilers compile, then why don't
> > objects object?
> >
> > fingerbirdy - fingerman's door to Firebird
> > http://www.fingerbird.de
> >
> >
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