IC69253: DOC: ESTIMATION OF MIN LOG REQUIRED IF DBSCHEDULER IS ENABLED IN11.50

APAR status

• Closed as documentation error.

Error description

• To prepare an instance that was 9.4 or 10.00 to run in 11.50,
  one thing of importance for increasing storage space is logical
  logs.
  
  Generally the size of log space depends on the operation type
  and activity the applications generate. The more update activity
  on the system, the faster the logs get filled up. This is
  especially so with smart blob updates, frequent checkpoints and
  when replication exists on the system. To regulate a smooth flow
  of transactions, log files must be backed up regularly.  One
  could configure the Scheduler to do the same.  Create a task in
  Scheduler to perform regular log checks and then back them up
  accordingly.
  
  Enable scheduler would increase log space used.  As the
  scheduler is enabled by default in 11.50, an update operation
  that sometimes met long transactions in 9.4 would finish and
  rollback without additional log files.  With dynamic log
  enabled, the same operation executes in 11.50 and the user would
  see a 50% log files increase.
  
  Currently there is no documentation written to help user
  estimate the minimum log space requirements for system log
  records in 11.50. Users are caught unprepared. It would help the
  user greatly if the Release Notes include a section of log
  requirements increase for 11.50.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of Version 11.50xC7 and and prior versions of      *
  * Informix                                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Information on the amount of logical-log spaces required     *
  * when upgrading to Version 11.50 was incomplete.              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Informix Version 11.50xC8.                        *
  ****************************************************************
  

Problem conclusion

• The "Checking and configuring available space" topic in the
  "Preparing for migration" section of the Migration Guide now
  specifies that you need the following space for building
  sysmaster, sysutils, and sysadmdatabases in Version 11.50:
  
  - 25214 KB of logical-log spaces (or 12607 pages) for 2 K page
  platforms
  - 30204 KB of logical-log spaces (or 7551 pages) for 4 K page
  platforms
  
  Two people on the Development team determined and tested the
  space requirements.
  

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

Applicable component levels