JasonLi-cn commented on code in PR #13249: URL: https://github.com/apache/datafusion/pull/13249#discussion_r1828614538
########## datafusion/optimizer/src/simplify_expressions/expr_simplifier.rs: ########## @@ -1675,12 +1675,34 @@ impl<'a, S: SimplifyInfo> TreeNodeRewriter for Simplifier<'a, S> { } } + // null <op> A --> null, + Expr::BinaryExpr(BinaryExpr { + left, + op: Eq | NotEq | Gt | GtEq | Lt | LtEq, + right: _, + }) if always_null(&left, info) => Transformed::yes(lit_bool_null()), + + // A <op> null --> null, + Expr::BinaryExpr(BinaryExpr { + left: _, + op: Eq | NotEq | Gt | GtEq | Lt | LtEq, + right, + }) if always_null(&right, info) => Transformed::yes(lit_bool_null()), + // no additional rewrites possible expr => Transformed::no(expr), }) } } +fn always_null<S: SimplifyInfo>(expr: &Expr, info: &S) -> bool { + is_null(expr) Review Comment: The `is_null` function cannot contain a non-`Expr::Literal` case where data type is `DataType::Null`(eg. Expr::Column). Maybe we should change the name of `always_null`? 🤔 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org