IC67450: ROLLBACK OF ALTER TABLE AGAINST A LARGE TABLE CAUSES THE ENGINE TO CRASH IN 11.50.FC4.

APAR status

• Closed as program error.

Error description

• The rollback of an ALTER TABLE against a large table schema will
  cause the engine to crash in 11.50.FC4.
  
  2 scenarios where this will occur:
  
  1) ALTER TABLE query is interrupted via CTRL C, resulting in a
  rollback which will cause the engine to crash.
  2) ALTER TABLE query becomes flagged as a long transaction,
  resulting in a rollback which will cause the engine to crash.
  
  Database has to be logged.
  Only occurs on large table schemas approx 60 columns or more
  
  With an Alter Table statement adding an additional column as
  follows:
  
  ALTER TABLE TEST_TABLE ADD
  NEW_COLUMN CHAR(32);
  
  You will see:
  
  17:18:09  Aborting Long Transaction: tx 0x0x5ff21b88 username:
  informix uid: 501
  17:18:09  stack trace for pid 21727 written to
  /usr2/products/11.50.FC4/tmp/af.42039a1
  17:18:09  Assert Failed: No Exception Handler
  17:18:09  IBM Informix Dynamic Server Version 11.50.FC4
  17:18:09   Who: Session(17, informix@xxx, 21916, 0x5ff21b88)
                 Thread(56, sqlexec, 5fee45c8, 1)
                 File: mtex.c Line: 491
  17:18:09   Results: Exception Caught. Type: MT_EX_OS, Context:
  mem
  17:18:09   Action: Please notify IBM Informix Technical Support.
  17:18:09   See Also: /usr2/products/11.50.FC4/tmp/af.42039a1,
  shmem.42039a1.0
  17:18:14  Starting crash time check of:
  17:18:14  1. memory block headers
  17:18:14  2. stacks
  17:18:14  Crash time checking found no problems
  17:18:14  mtex.c, line 491, thread 56, proc id 21727, No
  Exception Handler.
  17:18:15  Recursive Exception - Server exiting
  17:18:16  The Master Daemon Died
  17:18:20  PANIC: Attempting to bring system down
  17:18:20  semctl: errno = 22
  
  17:18:20  semctl: errno = 22
  
  
  IBM Informix Dynamic Server Version 11.50.FC4     -- On-Line
  (CKPT REQ) (LONGTX) -- Up 00:00:29 -- 484236 Kbytes Blocked:CKPT
  
  
  17:18:09  Stack for thread: 56 sqlexec
  
  base: 0x00000000615c3000
   len:   69632
    pc: 0x0000000001040be7
   tos: 0x000000000178a2a0
  state: running
    vp: 1
  
  afstack
  mt_ex_throw_sig
  afsig_handler
  <signal frame>
  openrel
  ddalter
  aud_ddalter
  excommand
  sq_execute
  sqmain
  spawn_thread
  startup
  
  This behavior is not seen in 11.50.xC5 and above.
  

Local fix

• Upgrade to 11.50.xC5 or higher
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of IDS 11.50XC4                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Server crashes when rollback of alter table statement        *
  * against a large table.                                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to 11.50.xC7 and above.                              *
  ****************************************************************
  

Problem conclusion

• Higher version >= 11.50.xC5 has the fix for the defect.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  IBM IDS ENTRP E

• Fixed component ID

  5724L2304

Applicable component levels

• RB15 PSY

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