Re: EAV (Re: Object-relational impedence)

From: Eric <eric_at_deptj.demon.co.uk>
Date: Fri, 21 Mar 2008 14:30:26 +0000
Message-ID: <slrnfu7hk2.l2s.eric_at_tasso.deptj.demon.co.uk>


On 2008-03-20, topmind <topmind_at_technologist.com> wrote:
>
>
> 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.)
>

And how much of it did you write? Looks to me like adding flexibility to the RM by removing defining features, also like solving a non-existent problem. But both of those are separate arguments.

I don't think it adds anything to this thread at all.

E Received on Fri Mar 21 2008 - 15:30:26 CET

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