Re: formula help please

From: Maxim Demenko <>
Date: Sun, 06 Jan 2008 12:39:28 +0100
Message-ID: <>

DA Morgan schrieb:

> Maxim Demenko wrote:

>> Totti schrieb:
>>> 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' post is:
>> <quote>
>> 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...
>> Best regards
>> Maxim
> The other exceptions would be if you have defined BITMAP JOINS INDEXES
> or DIMENSION objects.
> Consider, for example, the following syntax:
> CREATE BITMAP INDEX bjix_fact_prod
> ON facts (product.prod_name)
> FROM facts, products
> WHERE fact.prod_id = product.prod_id;

Still you have to specify join conditions *explicitly* ( as opposite to natural join, where join conditions are obtained by oracle *implicitly*) or am i missing something obvious?

Best regards

Maxim Received on Sun Jan 06 2008 - 05:39:28 CST

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