Re: Timely reporting of COPY errors - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Timely reporting of COPY errors
Date
Msg-id 200806232242.m5NMgck18425@momjian.us
Whole thread Raw
In response to Timely reporting of COPY errors  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-hackers
Added to TODO:
       o Allow COPY to report errors sooner
        http://archives.postgresql.org/pgsql-hackers/2008-04/msg01169.php


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Martijn van Oosterhout wrote:
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> Hi,
> 
> I notice that while doing bulk-loads that any errors detected by the
> backend arn't noticed by libpq until right at the end. Is this
> intentional? Looking at the code we have this comment in putCopyData:
> 
>   /*
>    * Process any NOTICE or NOTIFY messages that might be pending in the
>    * input buffer.  Since the server might generate many notices during the
>    * COPY, we want to clean those out reasonably promptly to prevent
>    * indefinite expansion of the input buffer.  (Note: the actual read of
>    * input data into the input buffer happens down inside pqSendSome, but
>    * it's not authorized to get rid of the data again.)
>    */
> 
> Except that pqSendSome won't try reading anything until it has a
> problem writing. Since the backend will consume copy data indefinitly,
> the error message sits in the kernel buffers until the end.
> 
> Is there anything that can be done? I've tried putting in
> PQconsumeInput in places but it doesn't appear to help.
> 
> Any ideas?
> -- 
> Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> > Please line up in a tree and maintain the heap invariant while 
> > boarding. Thank you for flying nlogn airlines.
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--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
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