vbarua commented on code in PR #14194:
URL: https://github.com/apache/datafusion/pull/14194#discussion_r1926006701


##########
datafusion/substrait/src/logical_plan/producer.rs:
##########
@@ -559,12 +559,31 @@ pub fn from_table_scan(
     let table_schema = scan.source.schema().to_dfschema_ref()?;
     let base_schema = to_substrait_named_struct(&table_schema)?;
 
+    let best_effort_filter_option = if !scan.filters.is_empty() {
+        let table_schema_qualified = Arc::new(
+            DFSchema::try_from_qualified_schema(
+                scan.table_name.clone(),
+                &(scan.source.schema()),
+            )
+            .unwrap(),
+        );
+        let mut combined_expr = scan.filters[0].clone();
+        for i in 1..scan.filters.len() {
+            combined_expr = combined_expr.and(scan.filters[i].clone());
+        }
+        let best_effort_filter_expr =
+            producer.handle_expr(&combined_expr, &table_schema_qualified)?;
+        Some(Box::new(best_effort_filter_expr))
+    } else {
+        None
+    };
+
     Ok(Box::new(Rel {
         rel_type: Some(RelType::Read(Box::new(ReadRel {
             common: None,
             base_schema: Some(base_schema),
             filter: None,
-            best_effort_filter: None,
+            best_effort_filter: best_effort_filter_option,

Review Comment:
   We should be setting the `filter` field for this, and not 
`best_effort_filter`. The `filter` on the DataFusion TableScan _must_ be 
applied, so it should not be treated as a best-effort filter here which is 
potentially ignorable.
   
   My understanding of the best-effort filter is that is an optimization that 
can be used to reduce the number of rows read from a datasource. IMO, the docs 
on the best-effort filter could use some clarifications. I've filed a 
[ticket](https://github.com/substrait-io/substrait/issues/778) for this.



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