Re: Visio and Oracle?

On Oct 23, 8:59 am, "Shakespeare" <what..._at_xs4all.nl> wrote:
> "Brian Peasland" <d..._at_nospam.peasland.net> schreef in berichtnews:471dfb7b$0$26455$88260bb3_at_free.teranews.com...
>
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>
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> > Henrootje wrote:
> >> I did not say that Visio is free. I am legally using Visio, that is
> >> why I wanted to use it.
> >> I am doing a degree in ICT (Bachelor of ICT) besides my job. One of
> >> the courses is desiging databases. That is why I want to analyze
> >> existing database structures.
> >> But according to the reactions here Visio is not the right tool to do
> >> this.
> >> Then I have to look for an alternative but budget is limited. I hoped
> >> there would be some tool(s) I could use to help me analyse existing
> >> databases.
> >> If you know of any good tools, I would like to know which those would
> >> be. Maybe I can find some student licensing program.
> >> But since I just started things do no t need to be overly complicated.
> >> Is there anything you can point me too?
>
> >> TIA, Henro
>
> > One of the tools I've used in the past is Happy Fish (weird name...). You
> > can find this tool here:
>
> >http://www.polderij.nl/happyfish/
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> > The tool is not free, but it is relatively inexpensive.
>
> > HTH,
> > Brian
>
> > --
> > ===================================================================
>
> > Brian Peasland
> > d..._at_nospam.peasland.net
> >http://www.peasland.net
>
> > Remove the "nospam." from the email address to email me.
>
> > "I can give it to you cheap, quick, and good.
> > Now pick two out of the three" - Unknown
>
> > --
> > Posted via a free Usenet account fromhttp://www.teranews.com
>
> I wonder how a tool can create an ERD from a database, since the steps from
> ERD to Datamodel are not 1 on 1..... Some decisions like resolving arcs, m-n
> relationships, (de)normalization etc will "disappear" in the process.
>
> <quote>
> Happy Fish combines ERD design with live database access to query or
> maintain an already developed database.
> <end quote>
>
> I think they confuse an ERD with a Data Model Diagram....
>
> Still looks useful though......
>
> Shakespeare
> (What's in an ERD)

And other things will mysteriously appear, for example, constraints between relationships. ("What's not in an ERD", so to speak).

I think that's all just showing the limitations inherent in moving from design to implementation, then going into reverse. If you have something poorly designed and/or implemented, there's going to be some real doozies. For ongoing maintenance, there's going to be a need for this type of tool, regardless. The more automated it can be, and the bigger the system, the more helpful. If reversing into design can't be made to work, that's a good sign to junk it all and start over.

jg

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