IT45318: POTENTIAL FOR DATA LOSS OR INDEX PROBLEMS IN TABLES LOCATED IN ROOT DBSPACE WHEN EXTENDED RESERVED PAGES ARE IN USE

APAR status

• Closed as program error.

Error description

• An instance using a sufficiently large number of logical logs,
  dbspaces, or chunks may be at risk of data loss or index errors
  for tables located in the root dbspace. There are a number of
  required conditions:
  
  1. Informix server version 12.10.xC16, 14.10.xC9, 14.10.xC10 or
  14.10.xC10W1, or a special build containing the fix for IT40986.
  2. For OS platforms where a 4 kB base page size is used, any of
  the following: at least 3727 logical logs, 429 dbspaces, or 429
  chunks.  For all other OS platforms, using a 2 kB base page
  size, any of the following: at least 1846 logical logs, 198
  dbspaces, or 198 chunks.
  
  3. Tables, including system catalogs, located in the root
  dbspace with an extent that follows within 1 - 31 pages of a
  reserved pages extent.
  4. A recent update to a data or index page of an in-scope table
  that has not been written to the chunk at the time of a
  checkpoint.
  
  If all of the above conditions are met then an affected page may
  be cleared within the buffer pool before the page is flushed to
  the chunk meaning that the update is lost. This could result in
  a missing data update or inconsistencies in index pages that may
  later give rise to an Assertion Failure such as "bfcheck: bad
  page."
  
  Secondary servers may also encounter rollforward errors when
  updating tables that are located within the root dbspace.
  

Local fix

• Databases with frequent update activity that are by default
  located within the root dbspace, such as sysadmin or syscdr, may
  be moved to a different dbspace.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of Informix Server 12.10.xC16, 14.10.xC9, 14.10.xC10   *
  * and 14.10.xC10W1.                                            *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Informix Server 12.10.xC16W1 (or higher),         *
  * 14.10.xC10W2 or 14.10.xC11 (or higher).                      *
  ****************************************************************
  See the following knowledge article for more details:
  https://supportcontent.ibm.com/support/pages/notification-and-ad
  ditional-details-pertaining-apar-it45318
  

Problem conclusion

• Fixed in Informix Server 12.10.xC16W1, 14.10.xC10W2 and
  14.10.xC11.
  

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

  INFORMIX SERVER

• Fixed component ID

  5725A3900

Applicable component levels