eejbyfeldt commented on code in PR #13249: URL: https://github.com/apache/datafusion/pull/13249#discussion_r1834439966
########## 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: Do we actually need that distinction? Or could we make all current usage of `is_null` use `always_null`? If that is the case it seems like we should just improve `is_null` instead. -- 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