Helen Borrie wrote:

> Sorry, I don't understand what you are saying here. Custom RI is the
>
>*alternative* to creating a foreign key, i.e. declarative RI, in situations
>where the effect of declarative RI is worse than the risk of a RI
>violation. You would not have both a FOREIGN KEY constraint *and* custom
>RI on this relationship.
>
>
>

What i mind is, why i need that index in custom RI. For a better
performance?

>If you need to apply custom RI triggers, be mindful of the possible
>outcomes if you use transaction configurations that are at the "dirty" end
>of the scale. ReadCommitted isolation, when carelessly used, allows the
>possibility of phantom rows and undesirable overwriting. Declarative RI
>-the FOREIGN KEY constraint - provides better protection than custom RI
>triggers against the integrity breakages inherent in such conditions.
>
>
>

I only need the beforedelete check. The existence check will be done at
app level so only allow insert via lookups to foreign tables.
In the beforedelete can happen that trouble?

TIA

german.