Re: Do columns with Null data take up space?

"DA Morgan" <damorgan_at_x.washington.edu> wrote in message news:1102128189.447748_at_yasure...
> Doug wrote:
>
> > If I create a table with 250 columns, and only fill 8, do the other
> > columns take up space? (My user wants to log tests. There can be as
> > many at 250 tests in a set, but normally only about 8. My user wants
> > one record per set so he can run some third party analytical software
> > against the test results.) Is Oracle 8i smart enough to compress the
> > null values down so they don't take up space if they are unused?
>
> If you create a table with more than four columns you are making a
> design mistake ... think vertically ... not horizontally.
>
> CREATE TABLE test (
> test_id NUMBER(10),
> person_id NUMBER(10),
> question_id NUMBER(3),
> result VARCHAR2(20));
>
> And then you don't have sparse data to worry about either.
> --
> Daniel A. Morgan
> University of Washington
> damorgan_at_x.washington.edu
> (replace 'x' with 'u' to respond)

Dan,

You may want to clarify that you mean four columns in a table for this particular situation (test results/survey). The OP may take it as a general guideline as it is written now. Received on Sun Dec 05 2004 - 09:19:10 CST