IT33917: CONTINOOUS PREPARE/DECLARE/FREE OF AN STATEMENT IN AN FOREACH LOOP IN SPL CAUSE A LINEAR MEMORY CONSUMPTION IN SESSION RALLOC

APAR status

• Closed as program error.

Error description

• When I have the following logic in an Stored Procedure
  
  create procedure sp ()
  
  foreach select into val1, val2 -- select returns 15 Mio ++ rows
         let variable = string|| string || string || val1 ||
  string .... || val2
         prepare ID from variable
         declare cursor on ID
  ...
         free cursor
         free ID
  end foreach
  
  end procedure;
  
  and execute this SP, it will continoously growth on sessions
  RALLOC part until SHMTOTAL or
  systems available memory.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of Informix Server prior to 12.10.xC15 and 14.10.xC5.  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * When the following logic is in a Stored Procedure:           *
  *                                                              *
  * create procedure sp ()                                       *
  *                                                              *
  * foreach select into val1, val2 -- select returns 15 Mio ++   *
  * rows                                                         *
  *        let variable = string|| string || string || val1 ||   *
  * string .... || val2                                          *
  *        prepare ID from variable                              *
  *        declare cursor on ID                                  *
  * ...                                                          *
  *        free cursor                                           *
  *        free ID                                               *
  * end foreach                                                  *
  *                                                              *
  * end procedure;                                               *
  *                                                              *
  * and the stored procedure is executed, it will continuously   *
  * growth in a sessions                                         *
  * RALLOC part until SHMTOTAL or the systems available memory.  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Informix Server 12.10.xC15 (when available) or    *
  * 14.10.xC5.                                                   *
  ****************************************************************
  

Problem conclusion

• Fixed in Informix Server 12.10.xC15 and 14.10.xC5.
  

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