On Sun, Jan 28, 2018 at 02:18:38PM -0500, Tom Lane wrote:
> Thomas Munro <[email protected]> writes:
> > On Thu, Jan 25, 2018 at 11:07 AM, Bruce Momjian <[email protected]> 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 <[email protected]> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ As you are, so once was I. As I am, so you will be. +
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diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml
new file mode 100644
index a8c0b57..42649d2
*** a/doc/src/sgml/ref/create_trigger.sgml
--- b/doc/src/sgml/ref/create_trigger.sgml
*************** UPDATE OF <replaceable>column_name1</rep
*** 501,509 ****
<para>
Modifying a partitioned table or a table with inheritance children fires
! statement-level triggers directly attached to that table, but not
statement-level triggers for its partitions or child tables. In contrast,
! row-level triggers are fired for all affected partitions or child tables.
If a statement-level trigger has been defined with transition relations
named by a <literal>REFERENCING</literal> clause, then before and after
images of rows are visible from all affected partitions or child tables.
--- 501,510 ----
<para>
Modifying a partitioned table or a table with inheritance children fires
! statement-level triggers directly attached to the referenced table, but not
statement-level triggers for its partitions or child tables. In contrast,
! row-level triggers are fired on the rows in effected partitions or
! child tables, even if they are not referenced in the query.
If a statement-level trigger has been defined with transition relations
named by a <literal>REFERENCING</literal> clause, then before and after
images of rows are visible from all affected partitions or child tables.
