Method null_count_column_expr

datafusion/pruning/src/pruning_predicate.rs:862–869

rewrite col --> col_null_count

(
        &mut self,
        column: &phys_expr::Column,
        column_expr: &Arc<dyn PhysicalExpr>,
        field: &Field,
    )

    /// rewrite col --> col_null_count
    fn null_count_column_expr(
        &mut self,
        column: &phys_expr::Column,
        column_expr: &Arc<dyn PhysicalExpr>,
        field: &Field,
    ) -> Result<Arc<dyn PhysicalExpr>> {
        self.stat_column_expr(column, column_expr, field, StatisticsType::NullCount)
    }

    /// rewrite col --> col_row_count
    fn row_count_column_expr(