name-like data (was: Pizza Example)
Date: Tue, 06 Apr 2004 00:36:11 +0200
Message-ID: <4071df57$0$561$e4fe514c_at_news.xs4all.nl>
ben brugman wrote:
> The value of constraining the length of a field in a database
> is (R or not R) that all applications should work with this
> length and do not need to work with a length above it.
> Having sensible length's for fields does not hamper using 'normal' names
> for things and makes building an application simpler and more sturdy.
> The width of a screen is limited, so is the height and allthough some
> applications now use a screen larger than 80x25, all databases designed
> during that time still function on larger screens.
> If larger fields are allowed, how do we present the contents of those fields
> on a limited screen. (Or on paper, say a pasport for example).
..or the paper noteblock on which many orders are taken.
But "30" is overprecise. Tony had to make a choice, he chose 30.
I am not criticizing that choice. The fact that he and many other
database designers still have to make it every time name-like data
come across puzzles me.
Just an example: most old programming languages had a strict max
length on variable names. No problem until someone wants automated
source maintenance. Allowing for just any size doesn't help either (it
doesn't seem to hurt Perl, though).
After all these years of programming languages and databases it seems weak that no generally accepted type "name" has surfaced. Hardware boundaries (80 columns, 32 bit integers) are appearantly easier to accept.
It would be nice to have some mostly valid assumptions about the length of name-like data types without this overprecision. I'm thinking of types with associated conventions: Something like: display 60 characters when screen-estate is abundant, scroll for more, display 30 when scarce (and scroll for more), and the assumptions on the population may be used by the DBMS for efficient handling.
But maybe there are to many side issues to hope for some general acceptance of such conventions.
> For a lot of products (like medication for example) there are three fields
> one with a very short name, a normal name and a long name. But the long
> name still has to fit in/on certain places. The short names should fit on
> small stickers for packeging etc. The middle name is the name normally used.
> The long name is the full name but still limited.
>
> Most humans can not handle names of a length longer than say 30/40/50
> characters.
>
>
> Having sensible constraints is sensible.
:-) Received on Tue Apr 06 2004 - 00:36:11 CEST