Re: POC PATCH: copy from ... exceptions to: (was Re: VLDB Features) - Mailing list pgsql-hackers

On 2024-01-18 10:10, jian he wrote:
> On Thu, Jan 18, 2024 at 8:57 AM Masahiko Sawada <sawada.mshk@gmail.com> 
> wrote:
>> 
>> On Thu, Jan 18, 2024 at 6:38 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> >
>> > Alexander Korotkov <aekorotkov@gmail.com> writes:
>> > > On Wed, Jan 17, 2024 at 9:49 AM Kyotaro Horiguchi
>> > > <horikyota.ntt@gmail.com> wrote:
>> > >> On the other hand, SAVE_ERROR_TO takes 'error' or 'none', which
>> > >> indicate "immediately error out" and 'just ignore the failure'
>> > >> respectively, but these options hardly seem to denote a 'location',
>> > >> and appear more like an 'action'. I somewhat suspect that this
>> > >> parameter name intially conceived with the assupmtion that it would
>> > >> take file names or similar parameters. I'm not sure if others will
>> > >> agree, but I think the parameter name might not be the best
>> > >> choice. For instance, considering the addition of the third value
>> > >> 'log', something like on_error_action (error, ignore, log) would be
>> > >> more intuitively understandable. What do you think?
>> >
>> > > Probably, but I'm not sure about that.  The name SAVE_ERROR_TO assumes
>> > > the next word will be location, not action.  With some stretch we can
>> > > assume 'error' to be location.  I think it would be even more stretchy
>> > > to think that SAVE_ERROR_TO is followed by action.
>> >
>> > The other problem with this terminology is that with 'none', what it
>> > is doing is the exact opposite of "saving" the errors.  I agree we
>> > need a better name.
>> 
>> Agreed.
>> 
>> >
>> > Kyotaro-san's suggestion isn't bad, though I might shorten it to
>> > error_action {error|ignore|log} (or perhaps "stop" instead of "error")?
>> > You will need a separate parameter anyway to specify the destination
>> > of "log", unless "none" became an illegal table name when I wasn't
>> > looking.  I don't buy that one parameter that has some special values
>> > while other values could be names will be a good design.  Moreover,
>> > what if we want to support (say) log-to-file along with log-to-table?
>> > Trying to distinguish a file name from a table name without any other
>> > context seems impossible.
>> 
>> I've been thinking we can add more values to this option to log errors
>> not only to the server logs but also to the error table (not sure
>> details but I imagined an error table is created for each table on
>> error), without an additional option for the destination name. The
>> values would be like error_action {error|ignore|save-logs|save-table}.
>> 
> 
> another idea:
> on_error {error|ignore|other_future_option}
> if not specified then by default ERROR.
> You can also specify ERROR or IGNORE for now.
> 
> I agree, the parameter "error_action" is better than "location".

I'm not sure whether error_action or on_error is better, but either way 
"error_action error" and "on_error error" seems a bit odd to me.
I feel "stop" is better for both cases as Tom suggested.

-- 
Regards,

--
Atsushi Torikoshi
NTT DATA Group Corporation