Re: Parallel Seq Scan

Hi,

this is the backtrace:
gdb /var/lib/pgsql/9.6/data/ /var/lib/pgsql/9.6/data/core.7877
GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-64.el7
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
>
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<http://www.gnu.org/software/gdb/bugs/>...
/var/lib/pgsql/9.6/data/: Success.
[New LWP 7877]
Missing separate debuginfo for the main executable file
Try: yum --enablerepo='*debug*' install
/usr/lib/debug/.build-id/02/20b77a9ab8f607b0610082794165fccedf210d
Core was generated by `postgres: postgres tpcds [loca'.
Program terminated with signal 11, Segmentation fault.
#0 0x0000000000490b56 in ?? ()
(gdb) bt full
#0 0x0000000000490b56 in ?? ()
No symbol table info available.
#1 0x0000000000003668 in ?? ()
No symbol table info available.
#2 0x00007f956249a008 in ?? ()
No symbol table info available.
#3 0x000000000228c498 in ?? ()
No symbol table info available.
#4 0x0000000000000001 in ?? ()
No symbol table info available.
#5 0x000000000228ad00 in ?? ()
No symbol table info available.
#6 0x0000000000493fdf in ?? ()
No symbol table info available.
#7 0x00000000021a8e50 in ?? ()
No symbol table info available.
#8 0x0000000000000000 in ?? ()
No symbol table info available.
(gdb) q

Is there something else I can do?

On Mon, Nov 16, 2015 at 8:59 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Mon, Nov 16, 2015 at 2:51 PM, Bert <biertie(at)gmail(dot)com> wrote:
> > I've just pulled and compiled the new code.
> > I'm running a TPC-DS like test on different PostgreSQL installations, but
> > running (max) 12queries in parallel on a server with 12cores.
> > I've configured max_parallel_degree to 2, and I get messages that backend
> > processes crash.
> > I am running the same test now with 6queries in parallel, and parallel
> > degree to 2, and they seem to work. for now. :)
> >
> > This is the output I get in /var/log/messages
> > Nov 16 20:40:05 woludwha02 kernel: postgres[22918]: segfault at
> 7fa3437bf104
> > ip 0000000000490b56 sp 00007ffdf2f083a0 error 6 in
> postgres[400000+5b5000]
> >
> > Is there something else I should get?
>
> Can you enable core dumps e.g. by passing the -c option to pg_ctl
> start? If you can get a core file, you can then get a backtrace
> using:
>
> gdb /path/to/postgres /path/to/core
> bt full
> q
>
> That should be enough to find and fix whatever the bug is. Thanks for
> testing.
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>

--
Bert Desmet
0477/305361