Purpose
Specifies the minimum number of values in an IN-list in order for it to qualify for IN-list rewrite query processing.
Field Group
Performance
Valid Range
1 through 32767
Default
512
Changes Take Effect
After the DBS Control Record has been written.
Usage Notes
The default setting is appropriate for most situations, and will give the best query performance.
IN-list rewrite processing precludes predicate simplification and block optimization during query processing. So in rare cases, using an IN-list rewrite for a query with an IN-list can result in a performance degradation, compared to processing without the rewrite. In these cases, you should increase the value of InListRewriteThreshold to a value greater than the number of values in the IN-list in the query.
Related Topics
- For more information on large IN-list processing, see Teradata Vantage™ - SQL Request and Transaction Processing, B035-1142.
- For information on other DBS Control fields related to IN-list processing, see InListRewriteOption and MaxNumInListRewrite.