Re: Messy data models (Re: Visualize database schema) - Mailing list pgsql-general

From Sébastien Lorion
Subject Re: Messy data models (Re: Visualize database schema)
Date
Msg-id CAGa5y0PwZB4ssaTwFBwkfrwpY11PPMXuth6WcXNx3+t37MDAgQ@mail.gmail.com
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In response to Messy data models (Re: Visualize database schema)  (Wolfgang Keller <feliphil@gmx.net>)
List pgsql-general
Short answer: no. Even with a good auto-layout, nothing (up to now) beats a human made one because the latter will incorporate semantic which is not available to the modeling tool; for example, positioning, spacing and routing of relations will respect some sense of aesthetic and organization that are quite subjective. The only practical solution to untangle a complex model is to split it into sub-models and use aliases to reference tables in another sub-model.

Sébastien

On Fri, Aug 17, 2012 at 9:07 AM, Wolfgang Keller <feliphil@gmx.net> wrote:
> Concerning auto-layout, most if not all tools I have used up to now
> make a mess for anything that is not dead simple.

If a data model can not be reasonably "untangled" by an auto-layout
algorithm (such as e.g. Graphviz) for display as a human-readable graph,
wouldn't that mean that this model is a mess from the modeling point of
view?

In fact, shouldn't reasonably well-designed data models at least mostly
follow SER principles? In that case, they could be displayed
essentially as a tree.

Could the "messy-ness" (or not) of the display of a data model (given
a standard alorithm such as Graphviz) be used as a criterion to judge
whether the model is actually well-structured?

Sincerely,

Wolfgang


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