Re: Misleading error message in logical decoding for binary plugins

On Wed, Sep 3, 2014 at 10:45 AM, Andres Freund <andres@2ndquadrant.com> wrote:
> On 2014-09-03 09:36:32 -0400, Robert Haas wrote:
>> On Fri, Aug 29, 2014 at 9:48 AM, Andres Freund <andres@2ndquadrant.com> wrote:
>> > On 2014-08-29 22:42:46 +0900, Michael Paquier wrote:
>> >> Hi all,
>> >>
>> >> Using a plugin producing binary output, I came across this error:
>> >> =# select data from pg_logical_slot_peek_changes('foo', NULL, NULL);
>> >> ERROR:  0A000: output plugin cannot produce binary output
>> >> LOCATION:  pg_logical_slot_get_changes_guts, logicalfuncs.c:404
>> >>
>> >> Shouldn't the error message be here something like "binary output plugin
>> >> cannot produce textual output"? The plugin used in my case produces binary
>> >> output, but what is requested from it with pg_logical_slot_peek_changes is
>> >> textual output.
>> >
>> > I don't like the new message much. It's imo even more misleading than
>> > the old message. How about
>> > "output pluing produces binary output but the sink only accepts textual data"?
>>
>> Maybe:
>>
>> ERROR: pg_logical_slot_peek_changes cannot be used with a plugin that
>> produces only binary output
>> HINT: Use pg_logical_slot_peek_binary_changes instead.
>
> That level has no knowledge of what it's used by, so I think that'd
> require bigger changes than worth it.

ERROR: this logical decoding plugin can only produce binary output
ERROR: logical decoding plugin "%s" can only produce binary output

?

-- 
Robert Haas
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