INFORMIX SERVER / 5725A3900 / B70 - IDS 11.70

In general, the problem appears to be related to thread1 running 
a stored procedure that selects 
the max value of some integer column.  In this case the integer 
column is also the primary key and 
contains an in-table unique index.  While this is happening, 
thread2 was doing an insert that added 
new highest values (~2000 rows) of this column and then gets 
rolled back.  There appears to be 
a small timing problem where the select is expecting to grab an 
index page from the buffer pool but 
instead gets a data page that leads to a ptmap assertion like 
below. 
 
The ptmap assertion looks comparable to: 
 
12:53:36  IBM Informix Dynamic Server Version 11.70.FC5 Software 
Serial Number AAA#B000000 
 
12:53:36  Assert Failed: ptmap 
12:53:36   Who: Session(2906, informix@server, 6685262, 
70000002072a7e0) 
                Thread(2962, sqlexec, 7000000206f1da0, 8) 
                File: rspartn.c Line: 3730 
12:53:36   Results: Could not complete operation on 
'informix:"informix".glbser_log_ird' 
12:53:36   Action: Run 'oncheck -cDI 
laube:"informix".glbser_log_ird' 
12:53:37  Raw hex dump of stack located in 
/opt/informix/tmp/af.f7a7b9 
f.rawstk 
12:53:37  Stack for thread: 2962 sqlexec 
 
 base: 0x0700000025d13000 
  len:   135168 
   pc: 0x00000001000916ec 
  tos: 0x0700000025d300c0 
state: running 
   vp: 8 
 
(oninit)afstack 
(oninit)afhandler 
(oninit)affail_interface 
(oninit)ptmapx 
(oninit)buffget 
(oninit)bt_fast_buffget 
(oninit)btposition 
(oninit)kposition 
(oninit)rsstart 
(oninit)fmstart 
(oninit)indexaggs 
(oninit)group_open 
(oninit)prepselect 
(oninit)subqprep 
(oninit)exsubq 
(oninit)ev_cb 
(oninit)new_eval 
(oninit)IPRA.$ip_evalexpr 
(oninit)runproc 
(oninit)udrlm_spl_execute 
(oninit)udrlm_exec_routine 
(oninit)udr_execute 
(oninit)exroutine 
(oninit)sq_exproc 
(oninit)sqmain 
(oninit)listen_verify 
(oninit)spawn_thread 
(oninit)startup 
 
Note, in my test case, the ptmap assertion is followed by an 
assertion like below "Thread exited with 1 buffers held" 
when the session shuts down after the ptmap: 
 
12:53:57  Assert Failed: Thread exited with 1 buffers held. 
 
12:53:57   Who: Session(2906, informix@server, 6685262, 
70000002072a7e0) 
                Thread(2962, sqlexec, 7000000206f1da0, 8) 
                File: rsshmem.c Line: 2152 
12:53:57   Results: Dynamic Server must abort 
12:53:57  Raw hex dump of stack located in 
/opt/informix/tmp/af.f7a7b9 
f.rawstk 
12:53:57  Stack for thread: 2962 sqlexec 
 
 base: 0x0700000025d13000 
  len:   135168 
   pc: 0x00000001000916ec 
  tos: 0x0700000025d324c0 
state: running 
   vp: 8 
 
(oninit)afstack 
(oninit)afhandler 
(oninit)afcrash_interface 
(oninit)rstcb_cleanup 
(oninit)destroy_session 
(oninit)sq_exit 
(oninit)sqmain 
(oninit)listen_verify 
(oninit)spawn_thread 
(oninit)startup

**************************************************************** 
* USERS AFFECTED:                                              * 
* Users of highly-stressed in-table indexes                    * 
**************************************************************** 
* PROBLEM DESCRIPTION:                                         * 
* See Error Description                                        * 
**************************************************************** 
* RECOMMENDATION:                                              * 
* Update to IBM Informix Server 11.70.xC9                      * 
****************************************************************

One possible workaround would be to drop the primary key and its 
unique index, then recreate a unique 
index detached along with a new primary key that uses this 
detached index.

Problem Fixed In IBM Informix Server 11.70.xC9

not known / see Local fix

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

27.07.2015
09.06.2017
09.06.2017

11.70.xC9