diff --git a/source/dnode/vnode/src/tsdb/tsdbMergeTree.c b/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
index 4347550c2d1bef28f31de0b1c69725e94fa1f11d..950c9348af69d8b4275785da95d0b64db490b811 100644
--- a/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
+++ b/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
@@ -177,6 +177,7 @@ int32_t tLDataIterOpen(struct SLDataIter **pIter, SDataFReader *pReader, int32_t
   (*pIter)->iSttBlk = index;
   if (index != -1) {
     (*pIter)->pSttBlk = taosArrayGet(pBlockLoadInfo->aSttBlk, (*pIter)->iSttBlk);
+    (*pIter)->iRow = ((*pIter)->backward) ? (*pIter)->pSttBlk->nRow : -1;
   }
 
 _exit:
@@ -306,7 +307,6 @@ bool tLDataIterNextRow(SLDataIter *pIter) {
 
   int32_t iBlockL = pIter->iSttBlk;
   SBlockData *pBlockData = loadBlockIfMissing(pIter);
-
   pIter->iRow += step;
 
   while (1) {
@@ -323,6 +323,7 @@ bool tLDataIterNextRow(SLDataIter *pIter) {
 
     if (iBlockL != pIter->iSttBlk) {
       pBlockData = loadBlockIfMissing(pIter);
+      pIter->iRow += step;
     }
   }
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index e404dd3d3a001c7da93049f96f800e59655c1430..facfdb9a628c11c9b35e1dfb9a529b564308e7bb 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -228,9 +228,11 @@ static SHashObj* createDataBlockScanInfo(STsdbReader* pTsdbReader, const STableK
   for (int32_t j = 0; j < numOfTables; ++j) {
     STableBlockScanInfo info = {.lastKey = 0, .uid = idList[j].uid};
     if (ASCENDING_TRAVERSE(pTsdbReader->order)) {
-      info.lastKey = pTsdbReader->window.skey - 1;
+      int64_t skey = pTsdbReader->window.skey;
+      info.lastKey = (skey > INT64_MIN)? (skey - 1):skey;
     } else {
-      info.lastKey = pTsdbReader->window.ekey + 1;
+      int64_t ekey = pTsdbReader->window.ekey;
+      info.lastKey = (ekey < INT64_MAX)? (ekey + 1):ekey;
     }
 
     taosHashPut(pTableMap, &info.uid, sizeof(uint64_t), &info, sizeof(info));
@@ -342,10 +344,12 @@ static int32_t initFilesetIterator(SFilesetIter* pIter, SArray* aDFileSet, STsdb
   pLReader->uid = 0;
   tMergeTreeClose(&pLReader->mergeTree);
 
-  pLReader->pInfo = tCreateLastBlockLoadInfo();
   if (pLReader->pInfo == NULL) {
-    tsdbDebug("init fileset iterator failed, code:%s %s", tstrerror(terrno), pReader->idStr);
-    return terrno;
+    pLReader->pInfo = tCreateLastBlockLoadInfo();
+    if (pLReader->pInfo == NULL) {
+      tsdbDebug("init fileset iterator failed, code:%s %s", tstrerror(terrno), pReader->idStr);
+      return terrno;
+    }
   }
 
   tsdbDebug("init fileset iterator, total files:%d %s", pIter->numOfFiles, pReader->idStr);
@@ -1892,7 +1896,7 @@ static bool initLastBlockReader(SLastBlockReader* pLBlockReader, STableBlockScan
 
   int32_t code =
       tMergeTreeOpen(&pLBlockReader->mergeTree, (pLBlockReader->order == TSDB_ORDER_DESC), pReader->pFileReader,
-          pReader->suid, pScanInfo->uid, &w, &pLBlockReader->verRange, pLBlockReader->pInfo);
+                     pReader->suid, pScanInfo->uid, &w, &pLBlockReader->verRange, pLBlockReader->pInfo);
   if (code != TSDB_CODE_SUCCESS) {
     return false;
   }
diff --git a/tests/script/tsim/parser/commit.sim b/tests/script/tsim/parser/commit.sim
index ae19a4803bc6bd0f75c2a307696d7b0fc6f1ecb6..a9bf8b26ebda178ed789f3119eac7203a6889f9b 100644
--- a/tests/script/tsim/parser/commit.sim
+++ b/tests/script/tsim/parser/commit.sim
@@ -97,6 +97,7 @@ while $loop <= $loops
   endw
   sql select count(*) from $stb
   if $data00 != $totalNum then
+    print expect $totalNum , actual: $data00
     return -1
   endi
   $loop = $loop + 1