> From: Greg Stein [mailto:gstein@lyra.org]
>
> On Sun, Jan 27, 2002 at 02:56:47PM +0100, Marcus Comstedt wrote:
> > Don't make the mistake of puting an == between "SQL" and "database".
> > SQL implies a _relational_ database, which I think is totally out of
> > place here. A hierarchical or object database seems far more
> > appropriate.
>
> I would prefer the relational database myself. It would be easier to
> answer
> questions like:
>
> "which files have the 'graph-input' property set on them?"
> "what revisions were committed by 'gstein'?"
> "in the revisions that gstein changed between 100 and 200, what files
were
> touched?"
>
> etc.
>
> It is rather difficult to formulate adhoc queries against hierarchical
or
> object databases. Although I do recognize that is because there isn't
a
> standardized query language like what SQL has done for relational
> databases.
>
> I don't see hierarchical as working (although I could probably learn
more
> about them). Object databases could work, I'd think. But that missing
> query
> language...
>
And don't overlook the fact that with modern commercial relational
database engines, it's feasible to create large and still fairly
efficient SQL representations of subsets of hierarchical, and object
database features. I'm sure lots of folks could come up with a long list
of reasons why using this implementation approach is cheaper in the long
run.
For my day to day real life work, I deal with such a system on a daily
basis. The main data structure that we manage is a tree. Our query
object allows the user too quickly and easily reason about arbitrary
sub-trees of the data on a very frequent basis, and it just generates
SQL.
Bill
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Received on Sat Oct 21 14:37:00 2006