Rule rewriter was doing the wrong thing with conditional INSTEAD rules
whose conditions might yield NULL. The negated qual to attach to the original query is properly 'x IS NOT TRUE', not 'NOT x'. This fix produces correct behavior, but we may be taking a performance hit because the planner is much stupider about IS NOT TRUE than it is about NOT clauses. Future TODO: teach prepqual, other parts of planner how to cope with BooleanTest clauses more effectively.
Showing
想要评论请 注册 或 登录