On 2018-Sep-26, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > On Wed, Sep 26, 2018 at 02:38:25PM +0200, Peter Eisentraut wrote:
> >> We could certainly address this by adding three or four or five new
> >> timestamps that cover all these varieties. But perhaps it's worth
> >> asking what these timestamps are useful for and which ones we really need.
>
> > Frankly, we might be fine with just documenting it and see if anyone
> > complains.
>
> I'm not for adding a bunch of new action-start timestamps without very
> clear use-cases for them, because each one we add means more gettimeday()
> overhead that might or might not ever be useful.
>
> I agree that it would be surprising for transaction timestamp to be newer
> than statement timestamp. So for now at least, I'd be satisfied with
> documenting the behavior.
Really? I thought it was practically obvious that for transaction-
controlling procedures, the transaction timestamp would not necessarily
be aligned with the statement timestamp. The surprise would come
together with the usage of the new feature, so existing users would not
be surprised in any way.
I do wonder how do other systems behave in this area, though.
--
Álvaro Herrera https://www.2ndQuadrant.com/
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