Re: [HACKERS] 6.5 cvs: can't drop table

I had to destroy test database to continue my tests.
Here is backtrace from postgres crashing on 10 tables joining:

14:10[mira]:~/app/sql>mkjoindata.pl --joins 10 --rows 20 | psql test

...............
select t0.a,t1.a as t1,t2.a as t2,t3.a as t3,t4.a as t4,t5.a as t5,t6.a as t6,t7.a as t7,t8.a as t8,t9.a as t9,t10.a as t10
from t0 ,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10
where t1.id = t0.id and t2.id=t0.id and t3.id=t0.id and t4.id=t0.id and t5.id=t0.id and t6.id=t0.id and t7.id=t0.id and t8.id=t0.id and t9.id=t0.id and t10.id=t0.id ;
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
We have lost the connection to the backend, so further processing is impossible. Terminating.

gdb /usr/local/pgsql/bin/postmaster core
GDB is free software and you are welcome to distribute copies of it
under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.16 (i486-slackware-linux),
Copyright 1996 Free Software Foundation, Inc...
Core was generated by /usr/local/pgsql/bin/postgres localhost megera test idle
'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libdl.so.1...done.
Reading symbols from /lib/libm.so.5...done.
Reading symbols from /usr/lib/libreadline.so...done.
Reading symbols from /usr/lib/libhistory.so...done.
Reading symbols from /lib/libtermcap.so.2...done.
Reading symbols from /lib/libncurses.so.3.0...done.
Reading symbols from /usr/lib/libc.so.5...done.
Reading symbols from /lib/ld-linux.so.1...done.
#0 0x80b6065 in equal ()
(gdb) bt
#0 0x80b6065 in equal ()
#1 0x80c7652 in pathorder_match ()
#2 0x80c7900 in better_path ()
#3 0x80c7863 in add_pathlist ()
#4 0x80bf551 in update_rels_pathlist_for_joins ()
#5 0x80c8b8b in gimme_tree ()
#6 0x80c8ae7 in geqo_eval ()
#7 0x80c99f2 in random_init_pool ()
#8 0x80c8c7b in geqo ()
#9 0x80bd6e6 in make_one_rel_by_joins ()
#10 0x80bd5ee in make_one_rel ()
#11 0x80c1e81 in subplanner ()
#12 0x80c1dff in query_planner ()
#13 0x80c2173 in union_planner ()
#14 0x80c1f55 in planner ()
#15 0x80e22e7 in pg_parse_and_plan ()
#16 0x80e240b in pg_exec_query_dest ()
#17 0x80e23cc in pg_exec_query ()
#18 0x80e3518 in PostgresMain ()
#19 0x80cc72c in DoBackend ()
#20 0x80cc26b in BackendStartup ()
#21 0x80cb9e7 in ServerLoop ()
#22 0x80cb573 in PostmasterMain ()
---Type <return> to continue, or q <return> to quit---
#23 0x80a2999 in main ()
#24 0x806131e in _start ()
(gdb)

Regards,

Oleg

On Tue, 25 May 1999, Oleg Bartunov wrote:

> Date: Tue, 25 May 1999 13:53:19 +0400 (MSD)
> From: Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>
> To: hackers(at)postgreSQL(dot)org
> Cc: tgl(at)sss(dot)pgh(dot)pa(dot)us
> Subject: [HACKERS] 6.5 cvs: can't drop table
>
> Hi,
>
> today I did some tests with current 6.5 from cvs and multiple joins.
> I did unpredictable server crashes, i.e. sometimes query works
> sometimes crashes. After about a hour of my experiments I can't drop table in
> my test database:
>
> 13:55[mira]:~/app/sql>mkjoindata.pl --joins 10 --rows 20 | psql test
>
> mkjoindata.pl - is my test script specially rewritten to get parameters
> from command line. It generates test data, sql commands and automatize
> process of postgres crashing :-) I attach this new version to my post.
>
> Regards,
>
> Oleg
>
> PS.
> Tom (Lane), sometimes I got an old behaivour of postgres on big joins -
> all memory (ram+swap) exhausted. I remember a week ago that was fixed
> and I certainly did the same tests without any problem.
>
> drop table t0;
> pqReadData() -- backend closed the channel unexpectedly.
> This probably means the backend terminated abnormally
> before or while processing the request.
> We have lost the connection to the backend, so further processing is impossible. Terminating.
>
> Backtrace:
> mira:/usr/local/pgsql/data/base/test# gdb /usr/local/pgsql/bin/postmaster core
> GDB is free software and you are welcome to distribute copies of it
> under certain conditions; type "show copying" to see the conditions.
> There is absolutely no warranty for GDB; type "show warranty" for details.
> GDB 4.16 (i486-slackware-linux),
> Copyright 1996 Free Software Foundation, Inc...
> Core was generated by /usr/local/pgsql/bin/postgres localhost megera test DROP
> '.
> Program terminated with signal 11, Segmentation fault.
> Reading symbols from /lib/libdl.so.1...done.
> Reading symbols from /lib/libm.so.5...done.
> Reading symbols from /usr/lib/libreadline.so...done.
> Reading symbols from /usr/lib/libhistory.so...done.
> Reading symbols from /lib/libtermcap.so.2...done.
> Reading symbols from /lib/libncurses.so.3.0...done.
> Reading symbols from /usr/lib/libc.so.5...done.
> Reading symbols from /lib/ld-linux.so.1...done.
> #0 0x806aa2b in heapgettup ()
> (gdb) bt
> #0 0x806aa2b in heapgettup ()
> #1 0x806b7d1 in heap_getnext ()
> #2 0x807ca56 in DeleteTypeTuple ()
> #3 0x807cbb5 in heap_destroy_with_catalog ()
> #4 0x8083128 in RemoveRelation ()
> #5 0x80e41ef in ProcessUtility ()
> #6 0x80e2486 in pg_exec_query_dest ()
> #7 0x80e23cc in pg_exec_query ()
> #8 0x80e3518 in PostgresMain ()
> #9 0x80cc72c in DoBackend ()
> #10 0x80cc26b in BackendStartup ()
> #11 0x80cb9e7 in ServerLoop ()
> #12 0x80cb573 in PostmasterMain ()
> #13 0x80a2999 in main ()
> #14 0x806131e in _start ()
> (gdb)
>
>
> _____________________________________________________________
> Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
> Sternberg Astronomical Institute, Moscow University (Russia)
> Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
> phone: +007(095)939-16-83, +007(095)939-23-83
>
>

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83