Re: [SQL] PostgreSQL server terminated by signal 11

> -----Message d'origine-----
> De : Tom Lane [mailto:tgl@sss.pgh.pa.us]
> Envoyé : jeudi, juillet 27, 2006 16:06
> À : Daniel Caune
> Cc : pgsql-sql@postgresql.org
> Objet : Re: [SQL] PostgreSQL server terminated by signal 11
>
> "Daniel Caune" <daniel.caune@ubisoft.com> writes:
> > My PostgreSQL server running on a Linux machine is terminated by signal
> > 11 whenever I try to create some indexes on a table, which contains
> > quite a lot of data.
>
> Judging from your examples it's got something to do with the partial
> index WHERE clause.  What PG version is this exactly?  If you leave out
> different parts of the WHERE, does it still crash?  Does the crash
> happen immediately after you give the command, or does it run for
> awhile?  It might be worth getting a stack trace from the failure
> (best way is to attach to the running backend with gdb, provoke the
> crash, and do "bt" --- search for "gdb" in the archives if you need
> details).
>
>             regards, tom lane

Quite a long time I didn't use gdb! :-)  Anyway I proceed as described hereafter; correct me if I was wrong.

> ps -eaf | grep postgres

postgres  2792  2789  0 21:50 pts/2    00:00:00 su postgres
postgres  2793  2792  0 21:50 pts/2    00:00:00 bash
postgres  2902     1  7 22:17 ?        00:01:10 postgres: dbo agora [local] idle

                                                                               
postgres  2952     1  2 22:32 ?        00:00:00 /usr/lib/postgresql/8.1/bin/postmaster -D /var/lib/postgresql/8.1/main
-cunix_socket_directory=/var/run/postgresql -c config_file=/etc/postgresql/8.1/main/postgresql.conf -c
hba_file=/etc/postgresql/8.1/main/pg_hba.conf-c ident_file=/etc/postgresql/8.1/main/pg_ident.conf 
postgres  2954  2952  0 22:32 ?        00:00:00 postgres: writer process

                                                                               
postgres  2955  2952  0 22:32 ?        00:00:00 postgres: stats buffer process

                                                                               
postgres  2956  2955  0 22:32 ?        00:00:00 postgres: stats collector process

                                                                               

I connected to the postgres server using psql and I retrieved the backend pid by executing the statement "SELECT
pg_backend_pid();"

I started gdb under the UNIX account postgres and I attached the backend process providing the pid returned by the
statement.

I run the command responsible for creating the index and I entered "continue" in gdb for executing the command.  After
awhile, the server crashes: 

  Program received signal SIGSEGV, Segmentation fault.
  0x08079e2a in slot_attisnull ()
  (gdb)
  Continuing.

  Program terminated with signal SIGSEGV, Segmentation fault.
  The program no longer exists.

I can't do "bt" since the program no longer exists.  How can I provide more information, stack trace, and so on?

--
Daniel