Re: varchar2(size)
From: Mark D Powell <Mark.Powell2_at_hp.com>
Date: Wed, 30 Sep 2009 08:22:05 -0700 (PDT)
Message-ID: <7c72ba3f-4058-4dc3-b6ac-9bfc309d5469_at_g23g2000yqh.googlegroups.com>
On Sep 29, 8:36 pm, John Hurley <johnbhur..._at_sbcglobal.net> wrote:
> On Sep 29, 7:46 pm, indytoatl <indyto..._at_gmail.com> wrote:
>
> snip
>
> > If I have a table with 200 fields that are all variable length what
> > would be the drawback be of making them all varchar2(100) so that I
> > don't have to guess a number for each field. The form users fill out
> > already has contraints for the same fields (ie, Last Name Field on
> > form has 20 space limit.).
>
> Why don't you just make them all 2000 characters apiece since 100
> might be too small?
>
> Most properly designed database tables do not have 200 columns in
> them.
>
> If the maximum size of a last name is 20 spaces ... why would you not
> use varchar2(20)?
>
> Has there been an ERD completed for this application?
Date: Wed, 30 Sep 2009 08:22:05 -0700 (PDT)
Message-ID: <7c72ba3f-4058-4dc3-b6ac-9bfc309d5469_at_g23g2000yqh.googlegroups.com>
On Sep 29, 8:36 pm, John Hurley <johnbhur..._at_sbcglobal.net> wrote:
> On Sep 29, 7:46 pm, indytoatl <indyto..._at_gmail.com> wrote:
>
> snip
>
> > If I have a table with 200 fields that are all variable length what
> > would be the drawback be of making them all varchar2(100) so that I
> > don't have to guess a number for each field. The form users fill out
> > already has contraints for the same fields (ie, Last Name Field on
> > form has 20 space limit.).
>
> Why don't you just make them all 2000 characters apiece since 100
> might be too small?
>
> Most properly designed database tables do not have 200 columns in
> them.
>
> If the maximum size of a last name is 20 spaces ... why would you not
> use varchar2(20)?
>
> Has there been an ERD completed for this application?
>> Most properly designed database tables do not have 200 columns in them. <<
The number of columns on a table has no realtionship to proper normalization. I have seen plenty of tables with less than 20 columns that were not normalized properly. It is not that uncommon either to have a few tables with over 100 columns assigned to them in a system.
IMHO -- Mark D Powell -- Received on Wed Sep 30 2009 - 10:22:05 CDT