diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index e8d5989e4d..0e8001708b 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -277,7 +277,12 @@ int32_t colDataMergeCol(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, int
       pColumnInfoData->varmeta.allocLen = len + oldLen;
     }
 
-    memcpy(pColumnInfoData->pData + oldLen, pSource->pData, len);
+    if (pSource->pData != NULL) {
+      memcpy(pColumnInfoData->pData + oldLen, pSource->pData, len);
+    } else {
+      ASSERT(len == 0);
+    }
+
     pColumnInfoData->varmeta.length = len + oldLen;
   } else {
     if (finalNumOfRows > (*capacity)) {
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index c157faecb1..af368d33e0 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -3219,7 +3219,7 @@ int32_t doMergeRowsInBuf(SIterInfo* pIter, uint64_t uid, int64_t ts, SArray* pDe
 
 static int32_t doMergeRowsInFileBlockImpl(SBlockData* pBlockData, int32_t rowIndex, int64_t key, SRowMerger* pMerger,
                                           SVersionRange* pVerRange, int32_t step) {
-  while (pBlockData->aTSKEY[rowIndex] == key && rowIndex < pBlockData->nRow && rowIndex >= 0) {
+  while (rowIndex < pBlockData->nRow && rowIndex >= 0 && pBlockData->aTSKEY[rowIndex] == key) {
     if (pBlockData->aVersion[rowIndex] > pVerRange->maxVer || pBlockData->aVersion[rowIndex] < pVerRange->minVer) {
       rowIndex += step;
       continue;
diff --git a/source/libs/executor/src/tsimplehash.c b/source/libs/executor/src/tsimplehash.c
index a5168d24ba..9fbe94200c 100644
--- a/source/libs/executor/src/tsimplehash.c
+++ b/source/libs/executor/src/tsimplehash.c
@@ -189,7 +189,7 @@ int32_t tSimpleHashPut(SSHashObj *pHashObj, const void *key, size_t keyLen, cons
   }
 
   while (pNode) {
-    if ((*(pHashObj->equalFp))(GET_SHASH_NODE_KEY(pNode, pNode->dataLen), key, keyLen) == 0) {
+    if ((keyLen == pNode->keyLen) && (*(pHashObj->equalFp))(GET_SHASH_NODE_KEY(pNode, pNode->dataLen), key, keyLen) == 0) {
       break;
     }
     pNode = pNode->next;
@@ -213,10 +213,12 @@ int32_t tSimpleHashPut(SSHashObj *pHashObj, const void *key, size_t keyLen, cons
 static FORCE_INLINE SHNode *doSearchInEntryList(SSHashObj *pHashObj, const void *key, size_t keyLen, int32_t index) {
   SHNode *pNode = pHashObj->hashList[index];
   while (pNode) {
-    if ((*(pHashObj->equalFp))(GET_SHASH_NODE_KEY(pNode, pNode->dataLen), key, keyLen) == 0) {
+    const char* p = GET_SHASH_NODE_KEY(pNode, pNode->dataLen);
+    ASSERT(keyLen > 0);
+
+    if (pNode->keyLen == keyLen && ((*(pHashObj->equalFp))(p, key, keyLen) == 0)) {
       break;
     }
-
     pNode = pNode->next;
   }