IT02615: SELECT WITH SUBSTRING CAN GENERATE BAD QUERY PLAN WITH FILTER WITH SUBSTRING IS IN CLAUSE WITH SUBSELECT

APAR status

• Closed as program error.

Error description

• A select statement with a substring can generate a bad query
  plan with filter with substring in in clause with subselect.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of 11.70.xC1 through 11.70.xC9.                        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * A query may use sub-optimal execution path under the         *
  * following conditions:                                        *
  *   - there exists a non-correlated subquery as filter, e.g.,  *
  * "col IN <subquery>" or "col = ANY <subquery>"                *
  *   - a subscripted column is used in the subquery predicate,  *
  * e.g. "col[1,4] IN <subquery>" or "col[1,4] = ANY <subquery>" *
  *   - for the column referenced (col), when subscripted, the   *
  * number of unique values for the subscripted column is        *
  * significantly less than the number of unique values for the  *
  * whole column (e.g., many rows have common prefixes)          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Update to IDS-11.70.xC9                                      *
  ****************************************************************
  

Problem conclusion

• Problem Fixed In IDS-11.70.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

  INFORMIX SERVER

• Fixed component ID

  5725A3900

Applicable component levels

• RB70 PSN

     UP