Re: Trigger behaviour not as stated

On Sun, Jan 28, 2018 at 02:18:38PM -0500, Tom Lane wrote:
> Thomas Munro <thomas.munro@enterprisedb.com> writes:
> > On Thu, Jan 25, 2018 at 11:07 AM, Bruce Momjian <bruce@momjian.us> wrote:
> >> ... The attached patch updates the docs to say
> >> statement-level triggers fire on the "referenced" table, while row-level
> >> triggers fire only on the "affected" table, (vs. all affected tables)
> >> even if they are not referenced in the query.  I would backpatch this to
> >> PG 10.
> 
> > I was trying to convey that, but it does seem a little terse and
> > cryptic.  Your addition of "referenced" and "only" make it clearer.
> 
> Hm, the first part of Bruce's change seems fine, but I think this wording:
> 
>      ...  In contrast,
> !    row-level triggers are fired only on affected partitions or child tables,
> !    even if they are not referenced in the query.
> 
> is still confusing.  How about something like
> 
>      In contrast, row-level triggers are fired for each actual row change,
>      including changes in partitions or child tables that are not directly
>      named in the query.
> 
> Possibly "row operation" would be better than "row change".

Uh, I don't think we want to highlight the statement vs row difference
here but the fact that statement triggers fire on the referenced object
and not on the effected rows.  I have attached an updated patch which I
think is an improvement.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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