diff --git a/src/query/pipeline/transforms/src/processors/transforms/transform_accumulating_async.rs b/src/query/pipeline/transforms/src/processors/transforms/transform_accumulating_async.rs
index d4e4455595b9e..ad8c53fdb3f62 100644
--- a/src/query/pipeline/transforms/src/processors/transforms/transform_accumulating_async.rs
+++ b/src/query/pipeline/transforms/src/processors/transforms/transform_accumulating_async.rs
@@ -26,6 +26,10 @@ use databend_common_pipeline_core::processors::Processor;
pub trait AsyncAccumulatingTransform: Send {
const NAME: &'static str;
+ async fn on_start(&mut self) -> Result<()> {
+ Ok(())
+ }
+
async fn transform(&mut self, data: DataBlock) -> Result