diff --git a/src/vnode/common/inc/dataformat.h b/src/vnode/common/inc/dataformat.h
index 7fd8f4e1063c8bce572a3b9426555d06a13fc216..63e54c9a57493a710c02664b0c140bbcd538a0f4 100644
--- a/src/vnode/common/inc/dataformat.h
+++ b/src/vnode/common/inc/dataformat.h
@@ -58,10 +58,24 @@ void     tdDataRowReset(SDataRow row);
  */
 typedef void *SDataRows;
 
+#define TD_DATA_ROWS_HEAD_LEN sizeof(int32_t)
+
 #define dataRowsLen(rs) (*(int32_t *)(rs))
 #define dataRowsSetLen(rs, l) (dataRowsLen(rs) = (l))
 #define dataRowsInit(rs) dataRowsSetLen(rs, sizeof(int32_t))
 
+void tdDataRowsAppendRow(SDataRows rows, SDataRow row);
+
+// Data rows iterator
+typedef struct {
+  int32_t totalLen;
+  int32_t len;
+  SDataRow row;
+} SDataRowsIter;
+
+void tdInitSDataRowsIter(SDataRows rows, SDataRowsIter *pIter);
+SDataRow tdDataRowsNext(SDataRowsIter *pIter);
+
 /* Data column definition
  * +---------+---------+-----------------------+
  * | int32_t | int32_t |                       |
@@ -80,12 +94,6 @@ typedef char *SDataCol;
  */
 typedef char *SDataCols;
 
-typedef struct {
-  int32_t  rowCounter;
-  int32_t  totalRows;
-  SDataRow row;
-} SDataRowsIter;
-
 // ----------------- Data column structure
 
 // ---- operation on SDataRow;
@@ -110,11 +118,6 @@ void     tdFreeSDataRow(SDataRow rdata);
 #define TD_DATACOLS_LEN(pDataCols) (*(int32_t *)(pDataCols))
 #define TD_DATACOLS_NPOINTS(pDataCols) (*(int32_t *)(pDataCols + sizeof(int32_t)))
 
-// ---- operation on SDataRowIter
-void    tdInitSDataRowsIter(SDataRows rows, SDataRowsIter *pIter);
-int32_t tdRdataIterEnd(SDataRowsIter *pIter);
-void    tdRdataIterNext(SDataRowsIter *pIter);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/vnode/common/src/dataformat.c b/src/vnode/common/src/dataformat.c
index ed03df6df27c632521b78f16d692ac330bceb719..707f7a8eb2d58688827d84e2d36d5ec18f73a362 100644
--- a/src/vnode/common/src/dataformat.c
+++ b/src/vnode/common/src/dataformat.c
@@ -58,7 +58,7 @@ int32_t tdAppendColVal(SDataRow row, void *value, SColumn *pCol, int32_t suffixO
     case TD_DATATYPE_DOUBLE:
     case TD_DATATYPE_TIMESTAMP:
       memcpy(dataRowIdx(row, pCol->offset + sizeof(int32_t)), value, rowDataLen[pCol->type]);
-      if (dataRowLen(row) > suffixOffset + sizeof(int32_t))
+      if (dataRowLen(row) < suffixOffset + sizeof(int32_t))
         dataRowSetLen(row, dataRowLen(row) + rowDataLen[pCol->type]);
       break;
     case TD_DATATYPE_VARCHAR:
@@ -81,26 +81,47 @@ int32_t tdAppendColVal(SDataRow row, void *value, SColumn *pCol, int32_t suffixO
 void tdDataRowCpy(void *dst, SDataRow row) { memcpy(dst, row, dataRowLen(row)); }
 void tdDataRowReset(SDataRow row) { dataRowSetLen(row, sizeof(int32_t)); }
 
-// ------ Codes below should be refactored
-
-SDataRow tdSDataRowDup(SDataRow rdata) { return NULL; }
-void     tdFreeSDataRow(SDataRow rdata) {
-  if (rdata == NULL) return;
-  free(rdata);
+void tdDataRowsAppendRow(SDataRows rows, SDataRow row) {
+  tdDataRowCpy((void *)((char *)rows + dataRowsLen(rows)), row);
+  dataRowsSetLen(rows, dataRowsLen(rows) + dataRowLen(row));
 }
 
+// Initialize the iterator
 void tdInitSDataRowsIter(SDataRows rows, SDataRowsIter *pIter) {
-  pIter->totalRows = TD_DATAROWS_ROWS(rows);
-  pIter->rowCounter = 1;
-  pIter->row = TD_DATAROWS_DATA(rows);
+  if (pIter == NULL) return;
+  pIter->totalLen = dataRowsLen(rows);
+
+  if (pIter->totalLen == TD_DATA_ROWS_HEAD_LEN) {
+    pIter->row = NULL;
+    return;
+  }
+
+  pIter->row = (SDataRow)((char *)rows + TD_DATA_ROWS_HEAD_LEN);
+  pIter->len = TD_DATA_ROWS_HEAD_LEN + dataRowLen(pIter->row);
 }
 
-void tdRdataIterNext(SDataRowsIter *pIter) {
-  pIter->rowCounter++;
-  pIter->row = pIter->row + TD_DATAROW_LEN(pIter->row);
+// Get the next row in Rows
+SDataRow tdDataRowsNext(SDataRowsIter *pIter) {
+  SDataRow row = pIter->row;
+  if (row == NULL) return NULL;
+
+  if (pIter->len >= pIter->totalLen) {
+    pIter->row = NULL;
+  } else {
+    pIter->row = (char *)row + dataRowLen(row);
+    pIter->len += dataRowLen(row);
+  }
+
+  return row;
 }
 
-int32_t tdRdataIterEnd(SDataRowsIter *pIter) { return pIter->rowCounter >= pIter->totalRows; }
+// ------ Codes below should be refactored
+
+SDataRow tdSDataRowDup(SDataRow rdata) { return NULL; }
+void     tdFreeSDataRow(SDataRow rdata) {
+  if (rdata == NULL) return;
+  free(rdata);
+}
 
 /**
  * Copy it
diff --git a/src/vnode/tsdb/src/tsdbCache.c b/src/vnode/tsdb/src/tsdbCache.c
index dfcafc0c3203e53553cb545e1d424c5eed2cf459..dacb36025370a27267bdc72557408c3f8db93974 100644
--- a/src/vnode/tsdb/src/tsdbCache.c
+++ b/src/vnode/tsdb/src/tsdbCache.c
@@ -30,5 +30,8 @@ int32_t tsdbFreeCache(STsdbCache *pHandle) { return 0; }
 
 void *tsdbAllocFromCache(STsdbCache *pCache, int64_t bytes) {
   // TODO: implement here
-  return NULL;
+  void *ptr = malloc(bytes);
+  if (ptr == NULL) return NULL;
+
+  return ptr;
 }
\ No newline at end of file
diff --git a/src/vnode/tsdb/src/tsdbMain.c b/src/vnode/tsdb/src/tsdbMain.c
index c6e696e7652dfc5bdd3a10e08599f1afeab69d69..155ad192064d74d329bb5605788a7fc81e71ffcc 100644
--- a/src/vnode/tsdb/src/tsdbMain.c
+++ b/src/vnode/tsdb/src/tsdbMain.c
@@ -409,14 +409,16 @@ static int32_t tdInsertRowToTable(STsdbRepo *pRepo, SDataRow row, STable *pTable
   int32_t level = 0;
   int32_t headSize = 0;
 
+  tSkipListRandNodeInfo(pTable->content.pData, &level, &headSize);
+
   // Copy row into the memory
-  SSkipListNode *pNode = tsdbAllocFromCache(pRepo->tsdbCache, headSize + TD_DATAROW_LEN(row));
+  SSkipListNode *pNode = tsdbAllocFromCache(pRepo->tsdbCache, headSize + dataRowLen(row));
   if (pNode == NULL) {
     // TODO: deal with allocate failure
   }
 
   pNode->level = level;
-  tdSDataRowCpy(row, SL_GET_NODE_DATA(pNode));
+  tdDataRowCpy(SL_GET_NODE_DATA(pNode), row);
 
   // Insert the skiplist node into the data
   tsdbInsertRowToTableImpl(pNode, pTable);
@@ -434,14 +436,14 @@ static int32_t tsdbInsertDataToTable(tsdb_repo_t *repo, SSubmitBlock *pBlock) {
 
   SDataRows     rows = pBlock->data;
   SDataRowsIter rDataIter, *pIter;
+  pIter = &rDataIter;
+  SDataRow row;
 
   tdInitSDataRowsIter(rows, pIter);
-  while (!tdRdataIterEnd(pIter)) {
-    if (tdInsertRowToTable(pRepo, pIter->row, pTable) < 0) {
+  while ((row = tdDataRowsNext(pIter)) != NULL) {
+    if (tdInsertRowToTable(pRepo, row, pTable) < 0) {
       // TODO: deal with the error here
     }
-
-    tdRdataIterNext(pIter);
   }
 
   return 0;
diff --git a/src/vnode/tsdb/tests/tsdbTests.cpp b/src/vnode/tsdb/tests/tsdbTests.cpp
index c60fd57b07ee471861d295ba1661732ffd6f32f2..534b75bfb664bd5a3d3ab739f94d538a72ae6bf5 100644
--- a/src/vnode/tsdb/tests/tsdbTests.cpp
+++ b/src/vnode/tsdb/tests/tsdbTests.cpp
@@ -4,7 +4,7 @@
 #include "tsdb.h"
 #include "tsdbMeta.h"
 
-TEST(TsdbTest, createTable) {
+TEST(TsdbTest, DISABLED_createTable) {
   STsdbMeta *pMeta = tsdbCreateMeta(100);
   ASSERT_NE(pMeta, nullptr);
 
@@ -54,6 +54,8 @@ TEST(TsdbTest, createRepo) {
 
   int32_t size = sizeof(SSubmitMsg) + sizeof(SSubmitBlock) + tdMaxRowDataBytes(config.schema) * 10 + sizeof(int32_t);
 
+  tdUpdateSchema(config.schema);
+
   SSubmitMsg *pMsg = (SSubmitMsg *)malloc(size);
   pMsg->numOfTables = 1;  // TODO: use api
 
@@ -67,21 +69,19 @@ TEST(TsdbTest, createRepo) {
 
   SDataRow row = tdNewDataRow(tdMaxRowDataBytes(config.schema));
   int64_t ttime = 1583508800000;
-  void *pDst = pBlock->data;
   for (int i = 0; i < 10; i++) {  // loop over rows
     ttime += (10000 * i);
     tdDataRowReset(row);
     for (int j = 0; j < schemaNCols(config.schema); j++) {
       if (j == 0) {  // set time stamp
-        tdAppendColVal(row, (void *)(&ttime), schemaColAt(config.schema, j), 24);
+        tdAppendColVal(row, (void *)(&ttime), schemaColAt(config.schema, j), 40);
       } else {       // set other fields
-        int val = 10;
-        tdAppendColVal(row, (void *)(&val), schemaColAt(config.schema, j), 24);
+        int32_t val = 10;
+        tdAppendColVal(row, (void *)(&val), schemaColAt(config.schema, j), 40);
       }
     }
 
-    dataRowCpy((void *)pDst, row);
-    pDst += dataRowLen(row);
+    tdDataRowsAppendRow(rows, row);
   }
 
   tsdbInsertData(pRepo, pMsg);