Controls the interpretation of using = and != with NULL.
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.
Unlike SQL Anywhere, Sybase IQ does not generate the warning “null value eliminated in aggregate function” (SQLSTATE=01003) for aggregate functions on columns containing NULL values.