Re: outer vs. inner join

Try it and find out.

Daniel Morgan

Steffen Ramlow wrote:

> the question is: what is better for read performance: outer or inner joining
> two tables:
>
> T1 (c1, c2, c3, r1)
> T2 (c1, c2, c3)
>
> c1 are the primary keys, T1 and T1 join on r1
>
> in the case that r1 has a null value - an inner join does not return rows -
> so i have to use an outer join because i wanna always see the T1 rows
>
> would it be better for performance when i insert a dummy row into T2
> (e.g. -1, null, null) and reference this dummy row always from T1 when the
> would be normally be a null value - now i can use an inner join
Received on Wed Apr 03 2002 - 15:14:09 CST