Preserve records batch order when SchemaCastScanExec is involved (#20)

datafusion-federation/src/schema_cast/mod.rs

@@ -4,7 +4,8 @@ use datafusion::error::{DataFusionError, Result};
 use datafusion::execution::{SendableRecordBatchStream, TaskContext};
 use datafusion::physical_plan::stream::RecordBatchStreamAdapter;
 use datafusion::physical_plan::{
-    DisplayAs, DisplayFormatType, ExecutionPlan, ExecutionPlanProperties, PlanProperties,
+    DisplayAs, DisplayFormatType, Distribution, ExecutionPlan, ExecutionPlanProperties,
+    PlanProperties,
 };
 use futures::StreamExt;
 use std::any::Any;
@@ -69,6 +70,12 @@ impl ExecutionPlan for SchemaCastScanExec {
         vec![&self.input]
     }
 
+    /// Prevents the introduction of additional `RepartitionExec` and processing input in parallel. 
+    /// This guarantees that the input is processed as a single stream, preserving the order of the data.
+    fn benefits_from_input_partitioning(&self) -> Vec<bool> {
+        vec![false]
+    }
+
     fn with_new_children(
         self: Arc<Self>,
         children: Vec<Arc<dyn ExecutionPlan>>,