Re: Parallel Seq Scan

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