Re: Constraint problem

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От Josh Berkus
Тема Re: Constraint problem
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Msg-id 200205161349.18499.josh@agliodbs.com
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Ответ на Re: Constraint problem  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
Ответы Re: Constraint problem  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
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Stephan,

> I unfortunately can't think of a good workaround. AFAICT, Unique should
> wait until after all of the updates but our implementation doesn't
> currently do so.
>
> Hopefully someone will have some ideas, because the best I can think of
> requires an additional full table scan to check uniqueness and the
> concurrency issues would be a bear.

Hmm ... I can put up with that, I think.  This table doesn't get modified very
often, and I can afford to table-level lock it during modification.

However, I can't think of how I could implement a BEFORE ... FOR EACH
STATEMENT trigger that would check for duplicates in the final result.  I can
only deal with one row at a time using the NEW record.

Suggestions?


--
-Josh Berkus

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