Re: Make COPY format extendable: Extract COPY TO format implementations

Hi,

In <CAD21AoDCd9pKZ2XMOUmnmteC60NYBLr80FWY56Nn3NEbxVxdeQ(at)mail(dot)gmail(dot)com>
"Re: Make COPY format extendable: Extract COPY TO format implementations" on Wed, 5 Feb 2025 12:29:44 -0800,
Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:

>> It seems that
>> FmgrInfo doesn't have return value type information. Should
>> we read pg_catalog.pg_proc or something for it?
>
> Yes, we can do like what we do for TABLESAMPLE for example:
>
> /* check that handler has correct return type */
> if (get_func_rettype(handlerOid) != TSM_HANDLEROID)
> ereport(ERROR,
> (errcode(ERRCODE_WRONG_OBJECT_TYPE),
> errmsg("function %s must return type %s",
> NameListToString(rts->method), "tsm_handler"),
> parser_errposition(pstate, rts->location)));

Thanks! I didn't know get_func_rettype().

I attach the v32 patch set. 0003 is only changed. The
following check is added. It's similar to TABLESAMPLE's one.

/* check that handler has correct return type */
if (get_func_rettype(handlerOid) != COPY_HANDLEROID)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("function %s must return type %s",
format, "copy_handler"),
parser_errposition(pstate, defel->location)));

Thanks,
--
kou