SQL4002 - Reusable ODP sort used

SQL4002
Message Text: Reusable ODP sort used
Cause Text: Conditions exist in the query which cause a sort to be used. This allowed the open data path (ODP) to be reusable. One of the following reasons may be the cause for the sort:
  • The query contains ordering columns (ORDER BY) from more than one table, or contains ordering columns from a secondary table of a join query that cannot be reordered.
  • The grouping and ordering columns are not compatible.
  • DISTINCT was specified for the query.
  • UNION was specified for the query.
  • The query had to be implemented using a sort. Key length of more than 2000 bytes, more than 120 ordering columns, or an ordering column containing a reference to an external user-defined function was specified for ordering.
  • The query optimizer chose to use a sort rather than an index to order the results of the query.
Recovery Text: A reusable ODP generally results in improved performance when compared to a non-reusable ODP.