Re: INSERT ... ON CONFLICT UPDATE/IGNORE 4.0

On Fri, May 1, 2015 at 10:10 AM, Andres Freund <andres@anarazel.de> wrote:
> On 2015-05-01 10:06:42 -0400, Robert Haas wrote:
>> On Fri, May 1, 2015 at 9:58 AM, Andres Freund <andres@anarazel.de> wrote:
>> > would you rather have EXCLUDED.data refer to the tuple version from
>> > VALUES (or a SELECT or ...) or to version from the BEFORE trigger?
>>
>> I think it would be completely shocking if it didn't refer to the
>> version returned by the BEFORE trigger.  My interpretation of the
>> semantics of BEFORE triggers is that, once the trigger has fired and
>> returned a new tuple, things should proceed just as if that new tuple
>> were the one originally provided by the user.
>
> Well, it's a BEFORE INSERT trigger, not a BEFORE UPDATE, that's why I'm
> not so sure that argument applies.

Would the BEFORE UPDATE trigger even fire in this case?

The thing is, suppose somebody puts a BEFORE INSERT trigger and a
BEFORE UPDATE trigger on the table, and each of those triggers does
this:

NEW.last_updated_time = clock_timestamp();
return NEW;

That should work, and should cover all cases, even if you're using UPSERT.

-- 
Robert Haas
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