diff --git a/source/libs/executor/inc/executorimpl.h b/source/libs/executor/inc/executorimpl.h
index cd7f5237bb..e35da0c45a 100644
--- a/source/libs/executor/inc/executorimpl.h
+++ b/source/libs/executor/inc/executorimpl.h
@@ -226,7 +226,6 @@ typedef struct SExecTaskInfo {
   char*            sql;                  // query sql string
   jmp_buf          env;                  // jump to this position when error happens.
   EOPTR_EXEC_MODEL execModel;            // operator execution model [batch model|stream model]
-  struct SSubplan  *plan;
   struct SOperatorInfo* pRoot;
 } SExecTaskInfo;
 
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index a1f150d3bf..04e9cf8cb2 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -5210,7 +5210,6 @@ int32_t createExecTaskInfoImpl(SSubplan* pPlan, SExecTaskInfo** pTaskInfo, SRead
     goto _complete;
   }
 
-  (*pTaskInfo)->plan = pPlan;
   return code;
 
 _complete:
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 008f83e935..1cb17ca493 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -1657,11 +1657,6 @@ int32_t diffFunction(SqlFunctionCtx* pCtx) {
 
   // initial value is not set yet
   if (numOfElems <= 0) {
-    /*
-     * 1. current block and blocks before are full of null
-     * 2. current block may be null value
-     */
-    assert(pCtx->hasNull);
     return 0;
   } else {
     return (isFirstBlock) ? numOfElems - 1 : numOfElems;