IT43566: FETCHING A LARGE NUMBER OF ROWS OF DATA FROM A DATABASE CAN BE VERY SLOW.

APAR status

• Closed as program error.

Error description

• When a database was asked to return such a large number of rows
  of data that it reported 'SQL_NO_TOTAL' that return code was not
  handled correctly.
  This meant that IIB and ACE retrieved the data using a very
  small row size leading to an excessive number of calls to
  retrieve all the rows of data.
  

Local fix

• Setting the MQSI_LOB_BUFFER_INCREMENT_SIZE environment variable
  can be used to temproarily work around this issue.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All users of IBM Integration Bus V10 and 10.1, and App Connect
  Enterprise versions 11 and 12 who retrieve a very large number
  of rows from a database in a single query.
  
  
  Platforms affected:
  AIX, HP-UX Itanium platform, Linux on Power platform, Linux on
  x86-64 platform, Solaris x86-64 platform, Linux on zSeries
  platform, Solaris SPARC platform, Windows on x86-64 platform,
  z/OS
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  When retrieving a very large number of rows from a database the
  database can return 'SQL_NO_TOTAL' to indicate that it does not
  know the exact number of rows to be returned.
  IBM Integration Bus and App Connect Enterprise did not handle
  the 'SQL_NO_TOTAL' return code and instead defaulted to
  retrieving 32 rows of data at a time from the database.
  This made retrieving a large result set unacceptably slow.
  

Problem conclusion

• The code that retrieves rows of data from a database has been
  changed so as it now handles the 'SQL_NO_TOTAL' return code from
  the database.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v10.1      10.1
  v11.0      11.0.0.20
  v12.0      12.0.6.0
  
  The latest available maintenance can be obtained from:
  http://www-01.ibm.com/support/docview.wss?rs=849&uid=swg27006041
  
  If the maintenance level is not yet available,information on
  its planned availability can be found on:
  http://www-1.ibm.com/support/docview.wss?rs=849&uid=swg27006308
  ---------------------------------------------------------------
  

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

  INTEGRATION BUS

• Fixed component ID

  5724J0540

Applicable component levels