diff --git a/src/common/inc/tdataformat.h b/src/common/inc/tdataformat.h
index 4e2974b09039427e32b97b3b22bb41c72de935a8..1637c4832b7e2ac9d4be52b7f94dd301ba4eb617 100644
--- a/src/common/inc/tdataformat.h
+++ b/src/common/inc/tdataformat.h
@@ -330,7 +330,6 @@ int tdAllocMemForCol(SDataCol *pCol, int maxPoints);
 void dataColInit(SDataCol *pDataCol, STColumn *pCol, int maxPoints);
 int dataColAppendVal(SDataCol *pCol, const void *value, int numOfRows, int maxPoints);
 void dataColSetOffset(SDataCol *pCol, int nEle);
-void dataColSetNEleNull(SDataCol *pCol, int nEle);
 
 bool isNEleNull(SDataCol *pCol, int nEle);
 
diff --git a/src/common/src/tdataformat.c b/src/common/src/tdataformat.c
index 3b48bf99772ebfa311fab0e2486203242723ec7f..c793d241f6f175268802830c6a96b35c689e69d1 100644
--- a/src/common/src/tdataformat.c
+++ b/src/common/src/tdataformat.c
@@ -19,6 +19,7 @@
 #include "wchar.h"
 #include "tarray.h"
 
+static void dataColSetNEleNull(SDataCol *pCol, int nEle);
 static void tdMergeTwoDataCols(SDataCols *target, SDataCols *src1, int *iter1, int limit1, SDataCols *src2, int *iter2,
                                int limit2, int tRows, bool forceSetNull);
 
@@ -297,7 +298,7 @@ static FORCE_INLINE void dataColSetNullAt(SDataCol *pCol, int index) {
   }
 }
 
-void dataColSetNEleNull(SDataCol *pCol, int nEle) {
+static void dataColSetNEleNull(SDataCol *pCol, int nEle) {
   if (IS_VAR_DATA_TYPE(pCol->type)) {
     pCol->len = 0;
     for (int i = 0; i < nEle; i++) {
diff --git a/src/tsdb/src/tsdbCommit.c b/src/tsdb/src/tsdbCommit.c
index 3b0db8da6afd9d59c9a5aab8f0b13001d846dd47..8f5f885d692f723bc1690a708571093bbe0a2717 100644
--- a/src/tsdb/src/tsdbCommit.c
+++ b/src/tsdb/src/tsdbCommit.c
@@ -920,7 +920,6 @@ int tsdbWriteBlockImpl(STsdbRepo *pRepo, STable *pTable, SDFile *pDFile, SDataCo
     SDataCol * pDataCol = pDataCols->cols + ncol;
     SBlockCol *pBlockCol = pBlockData->cols + nColsNotAllNull;
 
-    // if (isNEleNull(pDataCol, rowsToWrite)) {  // all data to commit are NULL, just ignore it
     if (isAllRowsNull(pDataCol)) {  // all data to commit are NULL, just ignore it
       continue;
     }
diff --git a/src/tsdb/src/tsdbReadImpl.c b/src/tsdb/src/tsdbReadImpl.c
index 237025864e207dc49fa2d59a53e1d8eb365c53f3..74d41cce194f9921ee0c521de9e329bad5eeb3f9 100644
--- a/src/tsdb/src/tsdbReadImpl.c
+++ b/src/tsdb/src/tsdbReadImpl.c
@@ -463,9 +463,6 @@ static int tsdbLoadBlockDataImpl(SReadH *pReadh, SBlock *pBlock, SDataCols *pDat
     SDataCol *pDataCol = &(pDataCols->cols[dcol]);
     if (dcol != 0 && ccol >= pBlockData->numOfCols) {
       // Set current column as NULL and forward
-      // TODO: tdAllocMemForCol may fail
-      /*tdAllocMemForCol(pDataCol, pDataCols->maxPoints);*/
-      /*dataColSetNEleNull(pDataCol, pBlock->numOfRows);*/
       dataColReset(pDataCol);
       dcol++;
       continue;
@@ -506,9 +503,6 @@ static int tsdbLoadBlockDataImpl(SReadH *pReadh, SBlock *pBlock, SDataCols *pDat
       ccol++;
     } else {
       // Set current column as NULL and forward
-      // TODO: tdAllocMemForCol may fail
-      /*tdAllocMemForCol(pDataCol, pDataCols->maxPoints);*/
-      /*dataColSetNEleNull(pDataCol, pBlock->numOfRows);*/
       dataColReset(pDataCol);
       dcol++;
     }
@@ -614,9 +608,6 @@ static int tsdbLoadBlockDataColsImpl(SReadH *pReadh, SBlock *pBlock, SDataCols *
       }
 
       if (pBlockCol == NULL) {
-        // TODO: tdAllocMemForCol may fail
-        /*tdAllocMemForCol(pDataCol, pDataCols->maxPoints);*/
-        /*dataColSetNEleNull(pDataCol, pBlock->numOfRows);*/
         dataColReset(pDataCol);
         continue;
       }