INFORMIX SERVER / 5725A3900 / B70 - IDS 11.70

If you mistakenly use the same column more then once in the
GROUP BY clause and one of the references is the column name
alias, while the other one is either the alias as well or the
column number, the engine crashes with the following messages in
the online.log:

15:21:31  stack trace for pid 5885 written to /tmp/af.4417ceb
15:21:31  Assert Failed: No Exception Handler
15:21:31  IBM Informix Dynamic Server Version 11.70.FC8W1
15:21:31   Who: Session(33, user@hostname, 6070, 0x4b8cb0a0)
                Thread(89, sqlexec, 4b8895d8, 8)
                File: mtex.c Line: 490
15:21:31   Results: Exception Caught. Type: MT_EX_OS, Context:
mem
15:21:31   Action: Please notify IBM Informix Technical Support.
15:21:31   See Also: /tmp/af.4417ceb
15:21:31  Assert Failed: Condition Failed (Ignoring free of pool
'33' (0x4dea0040) in use by blkpool), In (mt_shm_free_pool)
15:21:31  IBM Informix Dynamic Server Version 11.70.FC8W1
15:21:31   Who: Session(33, user@hostname, 6070, 0x4b8cb0a0)
                Thread(89, sqlexec, 4b8895d8, 8)
                File: mtshpool.c Line: 4685
15:21:31   Action: Please notify IBM Informix Technical Support.
15:21:31   See Also: /tmp/af.4417ceb, shmem.4417ceb.0

The stack of the failing thread looks like this:

afstack
mt_ex_throw_sig
afsig_handler

rdatavalVchar
ev_colret
new_eval
next_row
get_first_row_from_producer
hash_process_all_groups
group_open
prepselect
open_cursor
sql_open
sq_open
sqmain
spawn_thread
th_init_initgls
startup

Examples of SQL statements causing this type of crash:
    select tabname as crash_it, count(*) from systables group by
1, crash_it;
    select tabname as crash_it, count(*) from systables group by
crash_it, 1;
    select tabname as crash_it, count(*) from systables group by
crash_it, crash_it;

Examples of SQL statements NOT causing this type of crash:
    select tabname as crash_it, count(*) from systables group by
tabname, crash_it;
    select tabname as crash_it, count(*) from systables group by
crash_it, tabname;
    select tabname as crash_it, count(*) from systables group by
tabname, tabname;
-- the 3 above will return results, the one below returns the
'-201' error
    select tabname as crash_it, count(*) from systables group by
1,1;

****************************************************************
* USERS AFFECTED:                                              *
* production environment                                       *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
****************************************************************
* RECOMMENDATION:                                              *
* Update to IBM Informix Server 11.70.xC9                      *
****************************************************************

not known / see Local fix

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

02.11.2015
09.06.2017
09.06.2017

11.70.xC9