Re: Database designpattern - product feature

(Sorry Jan for receiving this twice)

@ Roxanne & Jan:
Thank you both for your Input. I absolutely see your point against EAV.

I will work out two variants based on the specific solution, where i would
create a (bigger) Table for each group of similar products, and based on
the dynamic JSON solution.
With this we can have a good discussion about the pros and cons in our next
meeting. In the end, the customer hast to decide how important the
flexibility is for him. (And yes, the customer has IT-People who will
understand why and what we talk about)

So thanks for doubting my approach, it has been helpful!

Freundliche Grüsse

Adrian Stern
unchained - web solutions

adrian(dot)stern(at)unchained(dot)ch
+41 79 292 83 47

On Thu, Jun 4, 2015 at 4:02 AM, Jan de Visser <jan(at)de-visser(dot)net> wrote:

> On June 3, 2015 02:04:28 PM Roxanne Reid-Bennett wrote:
> > I think you should evaluate your unease with having to update the
> database
> > on release (potentially many times) carefully for what it is and why you
> > have it. [I'm not saying it is invalid - just know why you have it]
> > Because no matter how well you design your system - databases evolve.
> > Manage that.
>
> Having been guilty of designing an EAV system before, I think I know his
> hesitation is due to the fact that some databases (*cough* Oracle *cough*)
> don't allow DDL in transactions (or at least back when I worked with
> Oracle it
> didn't), making dynamic table creation a bit of a problem, especially when
> you
> run in a container which gives you little flexibility in your tx handling
> (i.e. you get it all the time, or never). This used to be a problem in many
> iterations of J2EE containers. Also, lots of DBAs get skittish when they
> hear
> about applications doing DDL. And again, many of the technological
> roadblocks
> are fixed by now, but the hesitation remains.
>
> Combine this with the fact that you want users to be able to create new
> products, which should be built up out of existing and/or newly defined
> attributes, you quickly end up with something EAV like. Because you don't
> want
> your product management people coming crying to your DBAs to have a new
> table
> for a new product defined. You want the product management people to point-
> and-click their way through a nice GUI.
>
> So this is what lead me to that EAV design for this exact problem: we
> started
> off with Oracle as the database and a temperamental J2EE container, found
> out
> we couldn't do DDL (or at least DDL was hard), and by the time we were on
> less
> brain dead containers and databases the "damage" was done and there was no
> going back.
>
> But in my defense I will say that mine was one of the prettiest EAV systems
> ever built. In my opinion at least :-)
>
>
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