IT11956: QUERYING DATA COMPLETELY CACHED HAVING A LARGE NUMBER OF ITEMS IN AN "IN" CLAUSE CAN CAUSE SQLEXEC THREAD TO YIELD IMPROPERLY

APAR status

• Closed as program error.

Error description

• A query in question had > 10,000 host variable values for a
  column IN filter and was doing a sequential scan on a large
  table.  So when looking at rows to try and qualify for the
  result set, much of the data in the table did not satisfy the IN
  condition, and evaluating the expressions to determine the row
  that didn't qualify was taking a lot of cpu time and so the
  thread was not yielding frequently enough, which can negatively
  impact the server.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * users having large host variables or constant values in a    *
  * query as "IN" clause.                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Update to IBM Informix Server 11.70.xC9                      *
  ****************************************************************
  

Problem conclusion

• Problem Fixed In IBM Informix Server 11.70.xC9
  

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

• RA10 PSN

     UP