diff --git a/src/promptflow/promptflow/_sdk/_service/apis/collector.py b/src/promptflow/promptflow/_sdk/_service/apis/collector.py
index 97072da11ef..80cfc60014f 100644
--- a/src/promptflow/promptflow/_sdk/_service/apis/collector.py
+++ b/src/promptflow/promptflow/_sdk/_service/apis/collector.py
@@ -70,7 +70,7 @@ def trace_collector(
             for scope_span in resource_span.scope_spans:
                 for span in scope_span.spans:
                     # TODO: persist with batch
-                    span = Span._from_protobuf_object(span, resource=resource)
+                    span = Span._from_protobuf_object(span, resource=resource, logger=logger)
                     if not cloud_trace_only:
                         span._persist()
                     all_spans.append(span)
diff --git a/src/promptflow/promptflow/_sdk/_service/apis/line_run.py b/src/promptflow/promptflow/_sdk/_service/apis/line_run.py
index 8675d858fda..422b0a9ba8f 100644
--- a/src/promptflow/promptflow/_sdk/_service/apis/line_run.py
+++ b/src/promptflow/promptflow/_sdk/_service/apis/line_run.py
@@ -86,7 +86,7 @@ def get(self):
         client: PFClient = get_client_from_request()
         args = ListLineRunParser.from_request()
         line_runs: typing.List[LineRunEntity] = client._traces.list_line_runs(
-            session_id=args.session_id,
+            collection=args.session_id,
             runs=args.runs,
             experiments=args.experiments,
             trace_ids=args.trace_ids,
diff --git a/src/promptflow/promptflow/_sdk/entities/_trace.py b/src/promptflow/promptflow/_sdk/entities/_trace.py
index 83c574f8ddb..d4bce4ac7d3 100644
--- a/src/promptflow/promptflow/_sdk/entities/_trace.py
+++ b/src/promptflow/promptflow/_sdk/entities/_trace.py
@@ -5,6 +5,7 @@
 import copy
 import datetime
 import json
+import logging
 import typing
 import uuid
 from dataclasses import asdict, dataclass
@@ -42,6 +43,17 @@
 )
 
 
+class Event:
+    @staticmethod
+    def get(event_id: str) -> typing.Dict:
+        orm_event = ORMEvent.get(event_id)
+        data = json.loads(orm_event.data)
+        # deserialize `events.attributes.payload` here to save effort in UX
+        payload = data[SpanEventFieldName.ATTRIBUTES][SPAN_EVENTS_ATTRIBUTE_PAYLOAD]
+        data[SpanEventFieldName.ATTRIBUTES][SPAN_EVENTS_ATTRIBUTE_PAYLOAD] = json.loads(payload)
+        return data
+
+
 class Span:
     """Span is exactly the same as OpenTelemetry Span."""
 
@@ -100,10 +112,11 @@ def _persist_events(self) -> None:
 
     def _load_events(self) -> None:
         # load events from table `events` and update `events.attributes` inplace
+        events = []
         for i in range(len(self.events)):
             event_id = self.events[i][SpanEventFieldName.ATTRIBUTES][SPAN_EVENTS_ATTRIBUTES_EVENT_ID]
-            orm_event = ORMEvent.get(event_id)
-            self.events[i] = json.loads(orm_event.data)
+            events.append(Event.get(event_id=event_id))
+        self.events = events
 
     def _persist_line_run(self) -> None:
         # within a trace id, the line run will be created/updated in two cases:
@@ -188,11 +201,12 @@ def _from_protobuf_links(obj: typing.List[PBSpan.Link]) -> typing.List[typing.Di
         return links
 
     @staticmethod
-    def _from_protobuf_object(obj: PBSpan, resource: typing.Dict) -> "Span":
+    def _from_protobuf_object(obj: PBSpan, resource: typing.Dict, logger: logging.Logger) -> "Span":
         # Open Telemetry does not provide official way to parse Protocol Buffer Span object
         # so we need to parse it manually relying on `MessageToJson`
         # reference: https://github.com/open-telemetry/opentelemetry-python/issues/3700#issuecomment-2010704554
         span_dict: dict = json.loads(MessageToJson(obj))
+        logger.debug("Received span: %s, resource: %s", json.dumps(span_dict), json.dumps(resource))
         span_id = obj.span_id.hex()
         trace_id = obj.trace_id.hex()
         parent_id = obj.parent_span_id.hex()
diff --git a/src/promptflow/promptflow/_sdk/operations/_trace_operations.py b/src/promptflow/promptflow/_sdk/operations/_trace_operations.py
index 6f2b3a98cb3..27422efec10 100644
--- a/src/promptflow/promptflow/_sdk/operations/_trace_operations.py
+++ b/src/promptflow/promptflow/_sdk/operations/_trace_operations.py
@@ -2,23 +2,16 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # ---------------------------------------------------------
 
-import json
 import typing
 
-from promptflow._constants import SpanEventFieldName
-from promptflow._sdk._constants import SPAN_EVENTS_ATTRIBUTE_PAYLOAD
-from promptflow._sdk._orm.trace import Event as ORMEvent
 from promptflow._sdk._orm.trace import LineRun as ORMLineRun
 from promptflow._sdk._orm.trace import Span as ORMSpan
-from promptflow._sdk.entities._trace import LineRun, Span
+from promptflow._sdk.entities._trace import Event, LineRun, Span
 
 
 class TraceOperations:
     def get_event(self, event_id: str) -> typing.Dict:
-        data = json.loads(ORMEvent.get(event_id=event_id).data)
-        payload = data[SpanEventFieldName.ATTRIBUTES][SPAN_EVENTS_ATTRIBUTE_PAYLOAD]
-        data[SpanEventFieldName.ATTRIBUTES][SPAN_EVENTS_ATTRIBUTE_PAYLOAD] = json.loads(payload)
-        return data
+        return Event.get(event_id=event_id)
 
     def get_span(
         self,