Controls the interpretation of using = and != with NULL.
Option can be set at the database (PUBLIC) or user level. When set at the database level, the value becomes the default for any new user, but has no impact on existing users. When set 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.
With ANSINULL ON, results of comparisons with NULL using '=' or '!=' are unknown. This includes results of comparisons implied by other operations such as CASE.
Setting ANSINULL to OFF allows comparisons with NULL to yield results that are not unknown, for compatibility with Adaptive Server Enterprise.