Method mfp_filter

src/expr/src/interpret.rs:1080–1092

Override the default implementations of [Self::mfp_filter] and [Self::mfp_plan_filter] so that the fallibility of MFP expressions surfaces in the result, even when the expression's result column isn't referenced by a predicate or temporal bound. The runtime MFP evaluator runs every expression once all the preceding predicates pass (see [`crate::SafeMfpPlan::evaluate_inner`]), so an expression tha

(&self, mfp: &MapFilterProject)

    /// `fallible` flag and persist filter pushdown can wrongly discard a part
    /// that actually produces error rows. See database-issues#9656.
    fn mfp_filter(&self, mfp: &MapFilterProject) -> Self::Summary {
        let mfp_eval = MfpEval::new(self, mfp.input_arity, &mfp.expressions);
        let predicates = mfp
            .predicates
            .iter()
            .map(|(_, e)| mfp_eval.expr(e))
            .collect();
        let mut result = self.variadic(&And.into(), predicates);
        if mfp_eval.expressions.iter().any(|s| s.range.fallible) {
            result.range.fallible = true;
        }
        result
    }

    fn mfp_plan_filter(&self, plan: &MfpPlan) -> Self::Summary {
        let mfp_eval = MfpEval::new(self, plan.mfp.input_arity, &plan.mfp.expressions);