Feat : added truncate table support

datafusion/catalog/src/table.rs

@@ -353,6 +353,14 @@ pub trait TableProvider: Debug + Sync + Send {
     ) -> Result<Arc<dyn ExecutionPlan>> {
         not_impl_err!("UPDATE not supported for {} table", self.table_type())
     }
+
+    /// Remove all rows from the table.
+    ///
+    /// Should return an [ExecutionPlan] producing a single row with count (UInt64),
+    /// representing the number of rows removed.
+    async fn truncate(&self, _state: &dyn Session) -> Result<Arc<dyn ExecutionPlan>> {
+        not_impl_err!("TRUNCATE not supported for {} table", self.table_type())
+    }
 }
 
 /// Arguments for scanning a table with [`TableProvider::scan_with_args`].

datafusion/core/src/physical_planner.rs

@@ -655,6 +655,30 @@ impl DefaultPhysicalPlanner {
                     );
                 }
             }
+            LogicalPlan::Dml(DmlStatement {
+                table_name,
+                target,
+                op: WriteOp::Truncate,
+                ..
+            }) => {
+                if let Some(provider) =
+                    target.as_any().downcast_ref::<DefaultTableSource>()
+                {
+                    provider
+                        .table_provider
+                        .truncate(session_state)
+                        .await
+                        .map_err(|e| {
+                            e.context(format!(
+                                "TRUNCATE operation on table '{table_name}'"
+                            ))
+                        })?
+                } else {
+                    return exec_err!(
+                        "Table source can't be downcasted to DefaultTableSource"
+                    );
+                }
+            }
             LogicalPlan::Window(Window { window_expr, .. }) => {
                 assert_or_internal_err!(
                     !window_expr.is_empty(),

datafusion/core/tests/custom_sources_cases/dml_planning.rs

@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-//! Tests for DELETE and UPDATE planning to verify filter and assignment extraction.
+//! Tests for DELETE, UPDATE, and TRUNCATE planning to verify filter and assignment extraction.
 
 use std::any::Any;
 use std::sync::{Arc, Mutex};
@@ -24,9 +24,10 @@ use arrow::datatypes::{DataType, Field, Schema, SchemaRef};
 use async_trait::async_trait;
 use datafusion::datasource::{TableProvider, TableType};
 use datafusion::error::Result;
-use datafusion::execution::context::SessionContext;
+use datafusion::execution::context::{SessionConfig, SessionContext};
 use datafusion::logical_expr::Expr;
 use datafusion_catalog::Session;
+use datafusion_common::ScalarValue;
 use datafusion_physical_plan::ExecutionPlan;
 use datafusion_physical_plan::empty::EmptyExec;
 
@@ -165,6 +166,66 @@ impl TableProvider for CaptureUpdateProvider {
     }
 }
 
+/// A TableProvider that captures whether truncate() was called.
+struct CaptureTruncateProvider {
+    schema: SchemaRef,
+    truncate_called: Arc<Mutex<bool>>,
+}
+
+impl CaptureTruncateProvider {
+    fn new(schema: SchemaRef) -> Self {
+        Self {
+            schema,
+            truncate_called: Arc::new(Mutex::new(false)),
+        }
+    }
+
+    fn was_truncated(&self) -> bool {
+        *self.truncate_called.lock().unwrap()
+    }
+}
+
+impl std::fmt::Debug for CaptureTruncateProvider {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("CaptureTruncateProvider")
+            .field("schema", &self.schema)
+            .finish()
+    }
+}
+
+#[async_trait]
+impl TableProvider for CaptureTruncateProvider {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn schema(&self) -> SchemaRef {
+        Arc::clone(&self.schema)
+    }
+
+    fn table_type(&self) -> TableType {
+        TableType::Base
+    }
+
+    async fn scan(
+        &self,
+        _state: &dyn Session,
+        _projection: Option<&Vec<usize>>,
+        _filters: &[Expr],
+        _limit: Option<usize>,
+    ) -> Result<Arc<dyn ExecutionPlan>> {
+        Ok(Arc::new(EmptyExec::new(Arc::clone(&self.schema))))
+    }
+
+    async fn truncate(&self, _state: &dyn Session) -> Result<Arc<dyn ExecutionPlan>> {
+        *self.truncate_called.lock().unwrap() = true;
+
+        Ok(Arc::new(EmptyExec::new(Arc::new(Schema::new(vec![
+            Field::new("count", DataType::UInt64, false),
+        ])))))
+    }
+}
+
 fn test_schema() -> SchemaRef {
     Arc::new(Schema::new(vec![
         Field::new("id", DataType::Int32, false),
@@ -269,6 +330,28 @@ async fn test_update_assignments() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn test_truncate_calls_provider() -> Result<()> {
+    let provider = Arc::new(CaptureTruncateProvider::new(test_schema()));
+    let config = SessionConfig::new().set(
+        "datafusion.optimizer.max_passes",
+        &ScalarValue::UInt64(Some(0)),
+    );
+
+    let ctx = SessionContext::new_with_config(config);
+
+    ctx.register_table("t", Arc::clone(&provider) as Arc<dyn TableProvider>)?;
+
+    ctx.sql("TRUNCATE TABLE t").await?.collect().await?;
+
+    assert!(
+        provider.was_truncated(),
+        "truncate() should be called on the TableProvider"
+    );
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn test_unsupported_table_delete() -> Result<()> {
     let schema = test_schema();
@@ -295,3 +378,18 @@ async fn test_unsupported_table_update() -> Result<()> {
     assert!(result.is_err() || result.unwrap().collect().await.is_err());
     Ok(())
 }
+
+#[tokio::test]
+async fn test_unsupported_table_truncate() -> Result<()> {
+    let schema = test_schema();
+    let ctx = SessionContext::new();
+
+    let empty_table = datafusion::datasource::empty::EmptyTable::new(schema);
+    ctx.register_table("empty_t", Arc::new(empty_table))?;
+
+    let result = ctx.sql("TRUNCATE TABLE empty_t").await;
+
+    assert!(result.is_err() || result.unwrap().collect().await.is_err());
+
+    Ok(())
+}

datafusion/expr/src/logical_plan/dml.rs

@@ -237,6 +237,8 @@ pub enum WriteOp {
     Update,
     /// `CREATE TABLE AS SELECT` operation
     Ctas,
+    /// `TRUNCATE` operation
+    Truncate,
 }
 
 impl WriteOp {
@@ -247,6 +249,7 @@ impl WriteOp {
             WriteOp::Delete => "Delete",
             WriteOp::Update => "Update",
             WriteOp::Ctas => "Ctas",
+            WriteOp::Truncate => "Truncate",
         }
     }
 }

datafusion/proto/proto/datafusion.proto

@@ -278,6 +278,7 @@ message DmlNode{
     INSERT_APPEND = 3;
     INSERT_OVERWRITE = 4;
     INSERT_REPLACE = 5;
+    TRUNCATE = 6;
   }
   Type dml_type = 1;
   LogicalPlanNode input = 2;

datafusion/proto/src/logical_plan/from_proto.rs

@@ -239,6 +239,7 @@ impl From<protobuf::dml_node::Type> for WriteOp {
             }
             protobuf::dml_node::Type::InsertReplace => WriteOp::Insert(InsertOp::Replace),
             protobuf::dml_node::Type::Ctas => WriteOp::Ctas,
+            protobuf::dml_node::Type::Truncate => WriteOp::Truncate,
         }
     }
 }

datafusion/proto/src/logical_plan/to_proto.rs

@@ -729,6 +729,7 @@ impl From<&WriteOp> for protobuf::dml_node::Type {
             WriteOp::Delete => protobuf::dml_node::Type::Delete,
             WriteOp::Update => protobuf::dml_node::Type::Update,
             WriteOp::Ctas => protobuf::dml_node::Type::Ctas,
+            WriteOp::Truncate => protobuf::dml_node::Type::Truncate,
         }
     }
 }

datafusion/proto/tests/cases/roundtrip_logical_plan.rs

@@ -413,6 +413,7 @@ async fn roundtrip_logical_plan_dml() -> Result<()> {
         "DELETE FROM T1",
         "UPDATE T1 SET a = 1",
         "CREATE TABLE T2 AS SELECT * FROM T1",
+        "TRUNCATE TABLE T1",
     ];
     for query in queries {
         let plan = ctx.sql(query).await?.into_optimized_plan()?;

datafusion/sql/src/statement.rs

@@ -1390,6 +1390,56 @@ impl<S: ContextProvider> SqlToRel<'_, S> {
                     exec_err!("Function name not provided")
                 }
             }
+            Statement::Truncate(ast::Truncate {
+                table_names,
+                partitions,
+                identity,
+                cascade,
+                on_cluster,
+                table,
+            }) => {
+                let _ = table; // Support TRUNCATE TABLE and TRUNCATE syntax
+                if table_names.len() != 1 {
+                    return not_impl_err!(
+                        "TRUNCATE with multiple tables is not supported"
+                    );
+                }
+
+                let target = &table_names[0];
+                if target.only {
+                    return not_impl_err!("TRUNCATE with ONLY is not supported");
+                }
+                if partitions.is_some() {
+                    return not_impl_err!("TRUNCATE with PARTITION is not supported");
+                }
+                if identity.is_some() {
+                    return not_impl_err!(
+                        "TRUNCATE with RESTART/CONTINUE IDENTITY is not supported"
+                    );
+                }
+                if cascade.is_some() {
+                    return not_impl_err!(
+                        "TRUNCATE with CASCADE/RESTRICT is not supported"
+                    );
+                }
+                if on_cluster.is_some() {
+                    return not_impl_err!("TRUNCATE with ON CLUSTER is not supported");
+                }
+                let table = self.object_name_to_table_reference(target.name.clone())?;
+                let source = self.context_provider.get_table_source(table.clone())?;
+
+                // TRUNCATE does not operate on input rows. The EmptyRelation is a logical placeholder
+                // since the real operation is executed directly by the TableProvider's truncate() hook.
+                Ok(LogicalPlan::Dml(DmlStatement::new(
+                    table.clone(),
+                    source,
+                    WriteOp::Truncate,
+                    Arc::new(LogicalPlan::EmptyRelation(EmptyRelation {
+                        produce_one_row: false,
+                        schema: DFSchemaRef::new(DFSchema::empty()),
+                    })),
+                )))
+            }
             Statement::CreateIndex(CreateIndex {
                 name,
                 table_name,