chore: optimize SQL queries that perform partial full table scans (#24786)

api/core/app/apps/advanced_chat/generate_task_pipeline.py

@@ -73,7 +73,6 @@ from core.workflow.repositories.workflow_execution_repository import WorkflowExe
 from core.workflow.repositories.workflow_node_execution_repository import WorkflowNodeExecutionRepository
 from core.workflow.system_variable import SystemVariable
 from core.workflow.workflow_cycle_manager import CycleManagerWorkflowInfo, WorkflowCycleManager
-from events.message_event import message_was_created
 from extensions.ext_database import db
 from libs.datetime_utils import naive_utc_now
 from models import Conversation, EndUser, Message, MessageFile
@@ -939,10 +938,6 @@ class AdvancedChatAppGenerateTaskPipeline:
             self._task_state.metadata.usage = usage
         else:
             self._task_state.metadata.usage = LLMUsage.empty_usage()
-        message_was_created.send(
-            message,
-            application_generate_entity=self._application_generate_entity,
-        )
 
     def _message_end_to_stream_response(self) -> MessageEndStreamResponse:
         """

api/core/rag/index_processor/processor/parent_child_index_processor.py

@@ -130,13 +130,16 @@ class ParentChildIndexProcessor(BaseIndexProcessor):
                 if delete_child_chunks:
                     db.session.query(ChildChunk).where(
                         ChildChunk.dataset_id == dataset.id, ChildChunk.index_node_id.in_(child_node_ids)
-                    ).delete()
+                    ).delete(synchronize_session=False)
                     db.session.commit()
             else:
                 vector.delete()
 
                 if delete_child_chunks:
-                    db.session.query(ChildChunk).where(ChildChunk.dataset_id == dataset.id).delete()
+                    # Use existing compound index: (tenant_id, dataset_id, ...)
+                    db.session.query(ChildChunk).where(
+                        ChildChunk.tenant_id == dataset.tenant_id, ChildChunk.dataset_id == dataset.id
+                    ).delete(synchronize_session=False)
                     db.session.commit()
 
     def retrieve(