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Re: server Triggers

From: John P Cavanaugh <cavanaug_at_soco.agilent.com>
Date: 2001-03-03 00:20:55 CET

On Fri, Mar 02, 2001 at 02:33:27PM -0800, Bill Tutt wrote:
>
> 2) Performance really shouldn't be much of an issue for triggers because
> most triggers should be asynchronous triggers that fire after the commit
> succeeds. (The server doesn't block, and doesn't care if the trigger
> ever finishes)

I just hope most doesnt mean all. We should have both pre & post triggers
for items that modify the database (ie. labels, commits, renames, etc)

> Remember, we're in transacted system land now. Triggers aren't part of
> our non-existant two-phase commit system. You can't run triggers while
> the transaction is outstanding. (It could abort.) One could make the
> argument for synchronous triggers before the transaction even begins,
> but that just extends the period of time that might cause other
> transactions to come in and invalidate your work....

We will need some type of synchronous model then. Lots of times triggers
are written to prevent items from occuring thus having them run after
the fact is rather pointless.

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    John Cavanaugh Agilent Technologies
    R&D Program Manager 1400 Fountaingrove Pkwy
    CAD Data Store Santa Rosa, CA 95403-1799

    Email: cavanaug@soco.agilent.com Phone: 707-577-4780
                                                707-577-3948 (Fax)
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      As I grow older, I pay less attention to what men say. I
     just watch what they do.
                                           -- Andrew Carnegie
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Received on Sat Oct 21 14:36:25 2006

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