PI13695: EXCESSIVE GETPAGES ON INSERT WITHOUT COMMIT INTO UTS WITH GROSS LOCK (PSFIPTLK & PGSPUNC ON, PGRS1 & PGRS2 OFF)

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Excessive getpages on insert without commit into UTS with gross
  lock (PSFIPTLK & PGSPUNC on, PGRS1 & PGRS2 off) causes serious
  performance down and cpu shortage.
  

Local fix

• APPEND YES
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 for z/OS users of Universal Table    *
  *                 Space.                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Excessive get page count for long       *
  *                      running UR which is inserting           *
  *                      records into UTS with exclusive table   *
  *                      lock triggered by LOCK TABLE  or        *
  *                      lock escalation.                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The deleted space under partition level, table space level
  or the table level exclusive lock, did not consider to reuse
  pseudo deleted space. The intention is to preserve the
  space for queries that request the current committed data
  feature. However, when there is an exclusive gross lock on
  the object, no other UR can access the data. Therefore,
  deleted space should be reused by insert operations within
  the same UR.
  

Problem conclusion

• DB2 code is modified to consider reusing the pseudo deleted
  space that is enough  for inserting a record.
  This can improve some degree of the space reuse when there's
  a high level of exclusive lock activity.
  The higher level gross lock can be triggered either by lock
  escalation, LOCK TABLE or the LOCK SIZE TABLE/TABLESPACE
  statement.
  

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:

  UI18962 UI18963

Modules/Macros

• DSNIREPR DSNISGRT
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UI18962

     UP14/07/12 P F407

• RB10 PSY UI18963

     UP14/07/12 P F407

Fix is available

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