Re: Fix error message for MERGE foreign tables

On 2022-Oct-14, Michael Paquier wrote:

> On Fri, Oct 14, 2022 at 12:26:19PM +0800, Richard Guo wrote:
> > Maybe something like below, so that we keep it consistent with the case
> > of a foreign table being specified as a target.
> >
> > --- a/contrib/postgres_fdw/postgres_fdw.c
> > +++ b/contrib/postgres_fdw/postgres_fdw.c
> > @@ -1872,6 +1872,13 @@ postgresPlanForeignModify(PlannerInfo *root,
> > returningList,
> > &retrieved_attrs);
> > break;
> > + case CMD_MERGE:
> > + ereport(ERROR,
> > + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> > + errmsg("cannot execute MERGE on relation \"%s\"",
> > + RelationGetRelationName(rel)),
> > +
> > errdetail_relkind_not_supported(rel->rd_rel->relkind)));
> > + break;
>
> Yeah, you should not use an elog(ERROR) for cases that would be faced
> directly by users.

Yeah, I think this just flies undetected until it hits code that doesn't
support the case. I'll add a test and push as Richard suggests, thanks.

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Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/
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