Re: Do columns with Null data take up space?

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)