diff --git a/interactive_engine/compiler/ir_csr_ci.sh b/interactive_engine/compiler/ir_csr_ci.sh
index e2a98c797b23..1d86451cf8b4 100755
--- a/interactive_engine/compiler/ir_csr_ci.sh
+++ b/interactive_engine/compiler/ir_csr_ci.sh
@@ -5,16 +5,16 @@ cd ${base_dir}/../executor/ir/target/release &&
 RUST_LOG=info CSR_PATH=/tmp/gstest/modern_graph_csr_bin PARTITION_ID=0 ./start_rpc_server_csr --config ${base_dir}/../executor/ir/integrated/config &
 sleep 5s
 # start compiler service
-cd ${base_dir} && make run graph.store=rust-mcsr &
+cd ${base_dir} && make run graph.store=rust-mcsr gremlin.script.language.name=antlr_gremlin_calcite graph.physical.opt=proto graph.planner.opt=CBO graph.statistics=./src/test/resources/statistics/modern_statistics.json &
 sleep 5s
 # run gremlin standard tests
-cd ${base_dir} && make gremlin_test
+cd ${base_dir} && make gremlin_calcite_test
 exit_code=$?
 # clean service
 ps -ef | grep "com.alibaba.graphscope.GraphServer" | grep -v grep | awk '{print $2}' | xargs kill -9 || true
 ps -ef | grep "start_rpc_server" | grep -v grep | awk '{print $2}' | xargs kill -9
 # report test result
 if [ $exit_code -ne 0 ]; then
-    echo "ir integration test on experimental store fail"
+    echo "ir integration test on csr store fail"
     exit 1
 fi
diff --git a/interactive_engine/compiler/ir_experimental_ci.sh b/interactive_engine/compiler/ir_experimental_ci.sh
index 510efe100654..6d33630c7337 100755
--- a/interactive_engine/compiler/ir_experimental_ci.sh
+++ b/interactive_engine/compiler/ir_experimental_ci.sh
@@ -3,24 +3,26 @@ base_dir=$(cd $(dirname $0); pwd)
 
 # Test1: run gremlin standard tests on experimental store via ir-core
 # start engine service and load modern graph
-cd ${base_dir}/../executor/ir/target/release && RUST_LOG=info ./start_rpc_server --config ${base_dir}/../executor/ir/integrated/config &
-sleep 5s
-# start compiler service
-cd ${base_dir} && make run &
-sleep 5s
-# run gremlin standard tests
-cd ${base_dir} && make gremlin_test
-exit_code=$?
-# clean service
-ps -ef | grep "com.alibaba.graphscope.GraphServer" | grep -v grep | awk '{print $2}' | xargs kill -9 || true
-# report test result
-if [ $exit_code -ne 0 ]; then
-    echo "ir gremlin integration test on experimental store fail"
-    exit 1
-fi
+# cd ${base_dir}/../executor/ir/target/release && RUST_LOG=info ./start_rpc_server --config ${base_dir}/../executor/ir/integrated/config &
+# sleep 5s
+# # start compiler service
+# cd ${base_dir} && make run &
+# sleep 5s
+# # run gremlin standard tests
+# cd ${base_dir} && make gremlin_test
+# exit_code=$?
+# # clean service
+# ps -ef | grep "com.alibaba.graphscope.GraphServer" | grep -v grep | awk '{print $2}' | xargs kill -9 || true
+# # report test result
+# if [ $exit_code -ne 0 ]; then
+#     echo "ir gremlin integration test on experimental store fail"
+#     exit 1
+# fi
 
 # Test2: run gremlin standard tests on experimental store via calcite-based ir
-# restart compiler service
+# start engine service and load modern graph
+cd ${base_dir}/../executor/ir/target/release && RUST_LOG=info ./start_rpc_server --config ${base_dir}/../executor/ir/integrated/config &
+# start compiler service
 cd ${base_dir} && make run gremlin.script.language.name=antlr_gremlin_calcite graph.physical.opt=proto graph.planner.opt=CBO graph.statistics=./src/test/resources/statistics/modern_statistics.json &
 sleep 5s
 # run gremlin standard tests to test calcite-based IR layer
diff --git a/interactive_engine/executor/ir/integrated/tests/expand_test.rs b/interactive_engine/executor/ir/integrated/tests/expand_test.rs
index 78730da90ff0..9c895f0d5235 100644
--- a/interactive_engine/executor/ir/integrated/tests/expand_test.rs
+++ b/interactive_engine/executor/ir/integrated/tests/expand_test.rs
@@ -604,6 +604,39 @@ mod test {
         let v4: DefaultId = LDBCVertexParser::to_global_id(4, 0);
         let v5: DefaultId = LDBCVertexParser::to_global_id(5, 1);
         let v6: DefaultId = LDBCVertexParser::to_global_id(6, 0);
+        let mut expected_results = vec![(v1, 3), (v4, 2), (v6, 1)];
+        while let Some(Ok(record)) = pegasus_result.next() {
+            if let Some(v) = record.get(None).unwrap().as_vertex() {
+                if let Some(degree_obj) = record.get(Some(1)).unwrap().as_object() {
+                    results.push((v.id() as DefaultId, degree_obj.as_u64().unwrap()));
+                }
+            }
+        }
+        results.sort();
+        expected_results.sort();
+
+        assert_eq!(results, expected_results)
+    }
+
+    // g.V().as(0).select(0).by(out().count().as(1))
+    #[test]
+    fn expand_optional_out_degree_test() {
+        let expand_opr_pb = pb::EdgeExpand {
+            v_tag: None,
+            direction: 0,
+            params: None,
+            expand_opt: 2,
+            alias: Some(1.into()),
+            is_optional: true,
+        };
+        let mut pegasus_result = expand_degree_opt_test(expand_opr_pb);
+        let mut results = vec![];
+        let v1: DefaultId = LDBCVertexParser::to_global_id(1, 0);
+        let v2: DefaultId = LDBCVertexParser::to_global_id(2, 0);
+        let v3: DefaultId = LDBCVertexParser::to_global_id(3, 1);
+        let v4: DefaultId = LDBCVertexParser::to_global_id(4, 0);
+        let v5: DefaultId = LDBCVertexParser::to_global_id(5, 1);
+        let v6: DefaultId = LDBCVertexParser::to_global_id(6, 0);
         let mut expected_results = vec![(v1, 3), (v2, 0), (v3, 0), (v4, 2), (v5, 0), (v6, 1)];
         while let Some(Ok(record)) = pegasus_result.next() {
             if let Some(v) = record.get(None).unwrap().as_vertex() {
@@ -637,7 +670,9 @@ mod test {
         let v4: DefaultId = LDBCVertexParser::to_global_id(4, 0);
         let v5: DefaultId = LDBCVertexParser::to_global_id(5, 1);
         let v6: DefaultId = LDBCVertexParser::to_global_id(6, 0);
-        let mut expected_results = vec![(v1, 0), (v2, 1), (v3, 3), (v4, 1), (v5, 1), (v6, 0)];
+        // the zero-degree vertex should not be included in the result
+        // (v1, 0), (v2, 1), (v3, 3), (v4, 1), (v5, 1), (v6, 0)
+        let mut expected_results = vec![(v2, 1), (v3, 3), (v4, 1), (v5, 1)];
         while let Some(Ok(record)) = pegasus_result.next() {
             if let Some(v) = record.get(None).unwrap().as_vertex() {
                 if let Some(degree_obj) = record.get(Some(1)).unwrap().as_object() {
diff --git a/interactive_engine/executor/ir/runtime/src/process/operator/flatmap/edge_expand.rs b/interactive_engine/executor/ir/runtime/src/process/operator/flatmap/edge_expand.rs
index 4675c99d596a..3d5487335f52 100644
--- a/interactive_engine/executor/ir/runtime/src/process/operator/flatmap/edge_expand.rs
+++ b/interactive_engine/executor/ir/runtime/src/process/operator/flatmap/edge_expand.rs
@@ -87,8 +87,12 @@ impl<E: Entry + 'static> FlatMapFunction<Record, Record> for EdgeExpandOperator<
                         // the case of get degree.
                         ExpandOpt::Degree => {
                             let degree = iter.count();
-                            input.append(object!(degree), self.alias);
-                            Ok(Box::new(vec![input].into_iter()))
+                            if !self.is_optional && degree == 0 {
+                                Ok(Box::new(vec![].into_iter()))
+                            } else {
+                                input.append(object!(degree), self.alias);
+                                Ok(Box::new(vec![input].into_iter()))
+                            }
                         }
                     }
                 }