On Wed, Oct 26, 2016 at 2:12 PM, Andres Freund <and...@anarazel.de> wrote: > On 2016-10-26 13:49:12 -0500, Merlin Moncure wrote: >> On Wed, Oct 26, 2016 at 1:45 PM, Andres Freund <and...@anarazel.de> wrote: >> > >> > >> > On October 26, 2016 9:38:49 PM GMT+03:00, Merlin Moncure >> > <mmonc...@gmail.com> wrote: >> >>On Wed, Oct 26, 2016 at 1:34 PM, Andres Freund <and...@anarazel.de> >> >>wrote: >> >>> Any chance that plsh or the script it executes does anything with the >> >>file descriptors it inherits? That'd certainly one way to get into odd >> >>corruption issues. >> >> >> >>not sure. it's pretty small -- see >> >>https://github.com/petere/plsh/blob/master/plsh.c >> > >> > Afaics that could also be in your script, not just plsh. The later doesn't >> > seem to close all file handles above stderr, which means that all handles >> > for relations etc week be open in your script. If you e.g. do any unusual >> > redirections (2>&17 or such), that could end badly. But I'm just on my >> > phone, in a taxi without seatbelts, at 60mph, so I didn't look carefully. >> >> gotcha :-). see above: >> *) sqshf: >> #!/bin/bash >> cat \ >> $2 \ >> | eval "sqsh $1 -L'datetime=%Y-%m-%d %H:%M:%S.%u' -G 7.0" >> >> echo "Success" >> >> *) shexec: >> #!/bin/bash >> >> eval $1 >> >> FWICT that's all that's happening here with respect to pl/sh. > > My point is that that doesn't mean anything. Whatever sqsh is, or > whatever $1 eval's to (and $2 for that matter), could access the > filehandles the backend has opened.
I don't think that's the case. sqsh is a psql-like utility. it writes to stdout and stderr only which is captured by plsh and sent. In this context shexec only wraps rm -f 'file' where 'file' is a file previously created with COPY in the same transaction. In a test environment, spamming this routine with 16 threads I was not able to reproduce. Still hunting... merlin -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers