Re: dblink_error_message return value

On 09/25/2018 03:58 PM, Joe Conway wrote:
> On 09/25/2018 01:50 PM, Joe Conway wrote:
>> On 08/08/2018 11:57 AM, Tom Lane wrote:
>>> =?utf-8?q?PG_Doc_comments_form?= <noreply@postgresql.org> writes:
>>>> The following documentation comment has been logged on the website:
>>>> Documentation says:
>>> 
>>>> Return Value
>>>> Returns last error message, or an empty string if there has been no error in
>>>> this connection.
>>>> Which is invalid.
>>>> Actually it returns 'OK' string if no error was raised.
>>> 
>>> Good catch!  The code's quite clear about it, but the SGML docs need
>>> fixed.
>> 
>> 
>> As mentioned on the nearby thread, will fix. I suppose this ought to be
>> back-patched.
>> 
>> 
>>>> Secondly
>>>> dblink_is_busy must be first called to make dblink_error_message returns an
>>>> error message. (Tested on 9.6.9)
>>> 
>>> Meh.  I see what you're getting at here, I think, but that seems like a
>>> completely wrong/misleading statement of the issue.  Joe, can you think of
>>> better phraseology?
>> 
>> Maybe a note, something like this?
>> ------------
>> When asynchronous queries are initiated by dblink_send_query(), the
>> error message associated with the connection might not get updated until
>> the server's response message is consumed. This typically means that
>> dblink_is_busy() or dblink_get_result() should be called prior to
>> dblink_error_message(), so that any error generated by the asynchronous
>> query() will be visible.
>> ------------
> 
> And now with the corresponding patch attached.
> 
> Thoughts/comments?


Going once, going twice, ...
(if no complaints will commit soon)

Joe

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