Re: Need sql to pull data from terribly architected table

On Thu, Oct 25, 2012 at 2:42 AM, Steve Litt <slitt(at)troubleshooters(dot)com> wrote:
> Also, with the organization they're using, one can make new "columns"
> on the fly. ... Anyway, the keypuncher is punching
> data, comes across a brand new type of data (let's say "artist"), so
> for this row the keypuncher puts in a key-value pair of "artist=Lady
> Gaga". From a practical point of view, data structure could be change
> at key entry time, and needn't have been anticipated by the programmer
> nor recompiled or reorganized when a new type of data element entered
> the requirements.

That's wonderfully flexible, but it forfeits the protection that a
well-designed schema gives. A system like that is likely to end up
with different records storing the same data under slightly different
names, and you'll have a massive proliferation of "columns" that have
only a single row's value in them. That's fine if that's what you
want, but from a data entry standpoint, I think it's _too_ flexible
for most purposes.

ChrisA