IC72790: ASSERTION FAILURE WHEN SELECTING FROM A VIEW WHOSE DEFINITION INCLUDES A SELECT FROM ANOTHER VIEW IN IT'S PROJECTION LIST

APAR status

• Closed as program error.

Error description

• You execute a select against a view and it assert fails,
  possibly crashing the engine. The view definition includes a
  select from another view in it's projection list.
  
  An abbreviated view definition follows. Note that view view_1
  (definition not presented here) is represented in the projection
  list of view view_2.
  
  CREATE VIEW view_2 <column list> AS
  SELECT <projection list> ,
    (
      SELECT <projection list> FROM view_1 x1
      WHERE
      <conditions>
    ) , 0
  FROM view_1 x0
  WHERE
  <conditions>
  GROUP BY <fields>
  
  
  A select on the view returns error 874 or crashes the engine,
  depending on the platform:
  
  SELECT * FROM view_2 WHERE <column> IS NOT NULL;
  
  
  Stack trace in the assert fail file:
  
  unmapcol
  walkvcb
  walkvexpr
  walkvexpr
  opviewexpr
  viewinfo
  process_view_colltbl_expr
  processview
  foldviews
  qd_expandviews
  bldstructs
  sqcmd
  sq_cmnd
  sq_prepare
  sqmain
  listen_verify
  spawn_thread
  startup
  resume
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All 11.50 users.                                             *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * A query may generate assertion failure and -847 error under  *
  * the following conditions:                                    *
  *   - query involves a view                                    *
  *   - the view definition has correlated subquery in           *
  * projection clause                                            *
  *   - query has a IS NULL or IS NOT NULL predicate on the view *
  * subquery column                                              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to 11.50.xC9.                                        *
  ****************************************************************
  

Problem conclusion

• The problem is fixed in 11.50.xC9.
  

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

  IBM IDS ENTRP E

• Fixed component ID

  5724L2304

Applicable component levels

• RB15 PSN

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