Re: formula help please
Date: Sun, 06 Jan 2008 02:36:47 +0100
> statments, and as i understood from you, the constraints and the
> primary and foreign keys are essentials in solving such problems.
Essentials in solving such problems ( as it seems for me) from Charles'
Oracle has no automatic understanding of how one table should be joined to another table, even if foreign keys are defined </quote>
The only exception of this statement i am aware of (which is meaningless in this context, because you aren't using it - is natural join syntax). That means ( for me ) - if some tables are joined and cartesian product (leading to excessive row generation, cpu consumption and temp usage, what may appear as hang) should be avoided - then join conditions should be defined. Defining proper primary/foreign keys is not essential (but of course, may be helpful) to solve such problems...
Maxim Received on Sat Jan 05 2008 - 19:36:47 CST