Re: EAV (Re: Object-relational impedence)

Eric wrote:
> On 2008-03-20, topmind <topmind_at_technologist.com> wrote:
> > On Mar 20, 11:43 am, frebe <freb..._at_gmail.com> wrote:
> >> On 20 Mar, 18:39, topmind <topm..._at_technologist.com> wrote:
> >>
> >> > David Cressey wrote:
> >> > > "Eric" <e..._at_deptj.demon.co.uk> wrote in message
> >>
> >> > > > EAV is a way of misusing an RDBMS, and could be used for any subject
> >> > > > domain - and your schema description sounds like EAV.
> >>
> >> > EAV (attribute/value pair tables) is not always bad. It is one
> >> > approach to allowing user-definable "columns" and/or times when
> >> > dynamicy is needed so that a DBA does not have to do the new-column-
> >> > shuffle all the time.
> >>
> >> > I agree it can be a performance killer in some circumstances, but
> >> > often that's the tradeoff for flexibility.
> >>
> >> Using existing mainstream software development tools, I would agree
> >> that EAV is an necessary evil in many cases. The obvious solutions is
> >> of course to have better 4GL tools, which allow developers to more
> >> easily add fields in the database and the GUI. A while ago I had the
> >> doubtful pleasure of working with an application which was 100% EAV,
> >> and the flaws was pretty obvious. I have never seen such bad
> >> performance.
> >>
> >> //frebe
> >
> > http://www.c2.com/cgi/wiki?DynamicRelational
> >
> What on earth are you trying to prove by referencing that?

It was not to "prove" anything, but show *potential features* of a dynamic relational system. (Some don't like dynamic relational, but that's like the ol' Smalltalk versus Eiffel fights, except with relational instead of app langs.)

>
> E.

-T- Received on Fri Mar 21 2008 - 00:47:45 CET