Re: VisAD and SQL databases

• To: Ugo Taddei <p6taug@xxxxxxxxxxxxxxxxx>
• Subject: Re: VisAD and SQL databases
• From: Bill Hibbard <billh@xxxxxxxxxxxxx>
• Date: Tue, 21 Jan 2003 09:08:18 -0600 (CST)

Hi Ugo,

> How are you going to pass the information about which table is numerical
> and which is textual?

I know almost nothing about SQL. Can the interface tell from
the table itself (via JDBC calls, presumably) which domains
are numerical and which are text?

> For our app, we had
>
> ( x -> y) (FlatField, which represents a time series, i.e. a simple 2D plot)
>
> whereas you're suggesting
>
> ( record_index -> (x,y))
>
> which when mapped
> x -> XAxis
> and
> y -> YAxis
>
> is depicted as 2d scatter plot. (Am I right?)
>
> So I'm still with my approach (though I might take back my "it is
> impossible to write an adapter which will work with every JDBC-capable
> database" without adding at least "which will give you the data
> depiction you want" ;-)

That's right. The application still needs to seperate
independent and dependent variables as in:

> >If domains split into independent and dependent variables,
> >then the application would need to rearrange the MathType
> >to get something like:
> >
> >  ((domain1, domain2) -> (domain3, ..., domainN))
> >
> >with an appropriate domain Set. This is like what Donna has
> >done, constructing an Irregular2DSet.

Unless there's some way to find out from JDBC which domains are
independent variables and which are dependent. But probably no
way to find out whether the set of independent variables form
a Gridded or Irregular topology (this highlights a difference
between the VisAD and SQL data models).

Cheers,
Bill

• Follow-Ups:
  • Re: VisAD and SQL databases
    • From: Ugo Taddei

• References:
  • Re: VisAD and SQL databases
    • From: Ugo Taddei