PK87702: NON-LIST PREFETCH INDEX ACCESS

6.1.0.3 Download: WebSphere Portal and WCM V6.1 fix pack 3, 6.1.5 feature pack
6.1.0.4 Download: WebSphere Portal and WCM V6.1.0 fix pack 4 & 6.1.5 fix pack 1
6.1.0.5 Download: WebSphere Portal and WCM V6.1.0 fix pack 5
6.1.0.6 Download: WebSphere Portal and WCM V6.1.0 fix pack 6

APAR status

• Closed as program error.

Error description

• Purging Items in WCM is causing High CPU
  
  With the FOR UPDATE clause, DB2 must select an access
  path that would allow for any column to be updated. This rules
  out any index access other than list prefetch to avoid the so
  called "halloween update" problem. That is, with non-list
  prefetch index access, an update could move the row forward
  in the index such that it was found and updated again.
  .
  DB2 must choose either list prefetch or tablespace scan to
  avoid
  this problem. List prefetch is incompatible with IN list index
  access so matching on this index is restricted to column WSID
  which is not restrictive.This results in considerable getpages
  to the index and poor performance.
  

Local fix

Problem summary

• Code change was made.
  

Problem conclusion

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

  WEBSPHERE PORTA

• Fixed component ID

  5724E7600

Applicable component levels

• R60G PSY

     UP

• R60H PSY

     UP

• R60J PSY

     UP

• R61A PSY

     UP

• R61B PSY

     UP

• R610 PSY

     UP