PK80732: XPATH PERFORMANCE ENHANCEMENT AND XML INDEX SUPPORT FOR SOME XPATH FUNCTIONS

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• XPath Performance Enhancement (for DCR DK1239) and XML index
  support for some XPath functions (for DCR DK1185)
  - Pre-conditioning APAR for Runtime support.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: DB2 R910 Users who use XMLQUERY or XMLEXISTS *
  ****************************************************************
  * PROBLEM DESCRIPTION: For XMLQUERY or XMLEXISTS, the XPath    *
  *                      scanning algorithm is designed for      *
  *                      general cases and is not optimized      *
  *                      for simple but common cases.            *
  *                      Further for XMLEXISTS, there is no XML  *
  *                      index exploitation when XMLEXISTS       *
  *                      contains XPath function fn:upper-case() *
  *                      , fn:substring(), fn:starts-with(),     *
  *                      fn:exists() or fn:not().                *
  *                      Lacking specialized scanning            *
  *                      algorithm and index support for the     *
  *                      above XPaths hinders the query          *
  *                      performance.                            *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  For XMLQUERY or XMLEXISTS, the performance needs to be improved
  by optimizing the XPath scanning algorithm. Further for
  XMLEXISTS containing XPath function fn:upper-case(),
  fn:substring(), fn:starts-with(), fn:exists() or fn:not(),
  the performance needs to be enhanced by exploiting XML indexes.
  
  
  SOLUTION:
  DB2 is modified to optimize the XPath algorithm for
  XPath in XMLQUERY and XMLEXISTS, and is also modified to
  support XML index exploitation for XMLEXISTS containing XPath
  function fn:upper-case(), fn:substring(), fn:starts-with(),
  fn:exists() or fn:not().
  
  
  Additional keywords: XMLINDEXES
  

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:

  UK51214

Modules/Macros

• DSNNKGEN DSNNOCCN DSNNOGIK DSNNOIRT DSNNOKTS
  DSNNONTS DSNNORSQ DSNNOSCO DSNNOSER DSNNOSMS DSNNOTTS DSNNQFLR
  DSNNQIV  DSNNQLIB DSNNQOP  DSNNQSCN DSNNQTOP DSNNQXCA DSNNXEE
  DSNXEMG1 DSNXNODE DSNXOC   DSNXOIDX DSNXPAT  DSNXQFN  DSNXQND
  DSNXQTYP DSNXQUTL DSNXQXQ2 DSNXRL   DSNXRL2  DSNX5TRV DSNX5XEE
  DSNX5XNM DSNX5XPD DSNX5XQN DSNX5XSD
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• R910 PSY UK51214

     UP09/11/05 P F911

Fix is available

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