On 2021/02/05 16:52, Kasahara Tatsuhito wrote:
Hi,
The following is written in the comments of PQputCopyEnd().
(snip)
* Returns 1 if successful, 0 if data could not be sent (only possible
* in nonblock mode), or -1 if an error occurs.
(snip)
The PQputCopyEnd() section of the manual (libpq.sgml) describes the following.
The result is 1 if the termination message was sent; or in
nonblocking mode, this may only indicate that the termination
message was successfully queued. (In nonblocking mode, to be
certain that the data has been sent, you should next wait for
write-ready and call <xref linkend="libpq-PQflush"/>, repeating until it
returns zero.) Zero indicates that the function could not queue
the termination message because of full buffers; this will only
happen in nonblocking mode. (In this case, wait for
write-ready and try the <xref linkend="libpq-PQputCopyEnd"/> call
again.) If a hard error occurs, -1 is returned; you can use
<xref linkend="libpq-PQerrorMessage"/> to retrieve details.
These says that 0 may be returned if a non-blocking mode is used, but
there doesn't seem to be any case where 0 is returned in the code of
PQputCopyEnd().
I found the past discussion [1] about this issue.
[1]
https://www.postgresql.org/message-id/CA+Tgmobjj+0modbnmjy7ezeBFOBo9d2mAVcSPkzLx4LtZmc==g...@mail.gmail.com
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
