LI73046: THE DB2 DESIGN ADVISOR (DB2ADVIS) MAY CRASH THE DATABASE INSTANCE WHEN RECOMMENDING BLOCK INDEXES FOR MDC TABLES

DB2 Version 9.1 Fix Pack 7  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 5   for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 6   for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 6a for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 7a  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 8  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 9  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 10  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows

APAR status

• Closed as program error.

Error description

• When running the DB2 design advisor (db2advis) with
  MDC/clustering-index mode
  enabled, i.e., -m C, db2advis may cause the database instance to
  be brought down
  if a very complex query provided in the input workload contains
  an binary local
  predicate on a CHAR, VARCHAR, GRAPHIC or VARGRAPHIC column from
  a table that is
  large enough to warrant MDC recommendation investigation.
  
  The crash can occur only under the following conditions:
  1) The table of the column being compared is sufficiently big,
  i.e., at the very
     least, occupies 12 extents
  2) Statistics have been collected on the table
  3) The local predicate is placed in a certain order in the query
  
  The stack trace (with irrelevant information removed) in the
  event of such an
  instance crash will look identical to:
  ossDumpStackTrace + 0x0080
  _ZN11OSSTrapFile4dumpEmiP7siginfoPv + 0x00aa
  sqlo_trce + 0x033b
  sqloEDUCodeTrapHandler + 0x0074
  address: 0x0000002A957C9650 ; dladdress: 0x0000002A957BD000 ;
  offset in lib: 0x000000000000C650 ;
  address: 0x0000002A9714A8C5 ; dladdress: 0x0000002A958D2000 ;
  offset in lib: 0x00000000018788C5 ;
  address: 0x0000002A971455B3 ; dladdress: 0x0000002A958D2000 ;
  offset in lib: 0x00000000018735B3 ;
  _Z20sqlno_advise_indexesP13sqlno_globalsP13sqlno_contextP11sqlno
  _table9sqlno_setS5_ + 0x106b
  _Z23sqlno_crule_access_rootP13sqlno_globalsP13sqlno_context9sqln
  o_setS3_S3_S3_13SQLNN_BOOLEANS3_S3_P14sqlno_planlist + 0x074e
  _Z18sqlno_crule_accessP13sqlno_globalsP9sqlno_qtbP18sqlno_join_c
  ontext9sqlno_setS5_S5_S5_S5_13SQLNN_BOOLEANS5_ + 0x0171
  _Z14sqlno_plan_qunP13sqlno_globalsP9sqlno_sfbP9sqlnq_oprP9sqlnq_
  qun + 0x0255
  _Z13sqlno_call_sfP13sqlno_globalsP8sqlno_sfP9sqlno_sfbPvS5_i13SQ
  LNN_BOOLEAN + 0x0077
  _Z14sqlno_each_oprP13sqlno_globalsP9sqlno_sfbP9sqlnq_qunP9sqlnq_
  opr + 0x03a9
  _Z13sqlno_call_sfP13sqlno_globalsP8sqlno_sfP9sqlno_sfbPvS5_i13SQ
  LNN_BOOLEAN + 0x0077
  _Z14sqlno_walk_qunP13sqlno_globalsP9sqlno_sfbP9sqlnq_oprP9sqlnq_
  qun + 0x0085
  _Z13sqlno_call_sfP13sqlno_globalsP8sqlno_sfP9sqlno_sfbPvS5_i13SQ
  LNN_BOOLEAN + 0x0077
  _Z14sqlno_each_oprP13sqlno_globalsP9sqlno_sfbP9sqlnq_qunP9sqlnq_
  opr + 0x00e9
  _Z13sqlno_call_sfP13sqlno_globalsP8sqlno_sfP9sqlno_sfbPvS5_i13SQ
  LNN_BOOLEAN + 0x0077
  _Z14sqlno_walk_qunP13sqlno_globalsP9sqlno_sfbP9sqlnq_oprP9sqlnq_
  qun + 0x0085
  

Local fix

• No known local fix, but one can slightly generalize the input
  query by removing
  the specified predicate types under the given conditions.
  

Problem summary

• THE DB2 DESIGN ADVISOR (DB2ADVIS) MAY CRASH THE DATABASE
  INSTANCE WHEN RECOMMENDING BLOCK INDEXES FOR MDC TABLES
  

Problem conclusion

• First fixed in DB2 UDB Version 9.1, FixPak 5
  

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:

  LI73047

Fix information

• Fixed component name

  DB2 UDE ESE LIN

• Fixed component ID

  5765F4104

Applicable component levels

• R910 PSY

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