TOP_NSORT_CUTOFF_PAGES Option

1 – 1000

1

Option can be set at the database (PUBLIC) or user level. At the database level, the value becomes the default for any new user, but has no impact on existing users. At the user level, overrides the PUBLIC value for that user only. No system privilege is required to set option for self. System privilege is required to set at database level or at user level for any user other than self.

Requires the SET ANY PUBLIC OPTION system privilege to set this option. Can be set temporary for an individual connection or for the PUBLIC role. Takes effect immediately.

TOP_NSORT_CUTOFF_PAGES sets the threshold, measured in pages, where evaluation of a query that contains both a TOP clause and ORDER BY clause switches algorithms from ordered list-based processing to sort-based processing. Ordered list processing performs better in cases where the TOP N value is smaller than the number of result rows. Sort-based processing performs better for large TOP N values.

In some cases, increasing TOP_NSORT_CUTOFF_PAGES can improve performance by avoiding sort-based processing.