Re: design question
Date: Sun, 7 Sep 2008 13:34:54 +0200
DA Morgan wrote:
> Most things have NULL columns ... what's the issue?
A table with lets say 100 columns and 90 % NULLs in each row is no problem for the database performance and storage?
> If you don't store numbers as numbers you can not do math. If you do
> not store dates as dates you can not do date math. Storing everything
> as strings made sense on mainframes 20 years ago. It has no place in a
> modern RDBMS.
OK, one could change A in a way that the values are stored natively:
create table ObjectProperty (ID numeric(10), ObjectID numeric(10), Fieldname varchar2(50), FieldvalueV varchar2(4000), FieldvalueN numeric(30,2), FieldvalueD date);
So the question is basicly sould I use one row per value (A) or one row per object (B)?
I think B is better for the database but A is more flexible if new object types have to be stored. Received on Sun Sep 07 2008 - 06:34:54 CDT