[Koha-devel] Extended attributes, making them generic ?

[Dobrica Pavlinusic]

On Tue, Sep 17, 2013 at 07:41:04AM -0700, Galen Charlton wrote:
> > What it means :
> >  * changing the table name ! (now, it's borrowers_attributes and
> > borrowers_attribute_types)
> >  * removing foreign keys to borrowers table.
> >
> 
> However, I don't think it should be implemented in such a way that it drops
> foreign key constraints, of which we need more in Koha, not fewer.
>  Instead, I propose that each class we want to give extended attributes to
> get a separate table.

We are heavily using extended patron attributes (about 10 for each
borrower) and I also think that different tables is better solution
since droping referential integrity is never good idea (IMHO). Droping
it would also mean some sort of performance penalty (if we don't create
additional indexes) when joining with "master" tables (borrowers etc in
future).

But real justification for one single extended attributes might be that
we want to somehow generate reports which access more than one type of
extended attributes. I can't think of any example of such use-case, so
that's why I do prefer separate smaller tables for each extended attribute
type (which, as side-effect might be beneficial for performance and we
can keep referential integrity on them).

-- 
Dobrica Pavlinusic               2share!2flame            dpavlin at rot13.org
Unix addict. Internet consultant.             http://www.rot13.org/~dpavlin