diff --git a/src/tsdb/src/tsdbRWHelper.c b/src/tsdb/src/tsdbRWHelper.c
index 5b65b2185a873b9ea241b0b0e4147a4e9d522e48..8e57066d2703b40c647e5f7df9065abe3a77ff20 100644
--- a/src/tsdb/src/tsdbRWHelper.c
+++ b/src/tsdb/src/tsdbRWHelper.c
@@ -917,6 +917,8 @@ static int tsdbInsertSuperBlock(SRWHelper *pHelper, SCompBlock *pCompBlock, int
     ASSERT(pHelper->pCompInfo->blocks[0].keyLast < pHelper->pCompInfo->blocks[1].keyFirst);
   }
 
+  ASSERT((blkIdx == pIdx->numOfBlocks -1) || (!pCompBlock->last));
+
   tsdbDebug("vgId:%d tid:%d a super block is inserted at index %d", REPO_ID(pHelper->pRepo), pHelper->tableInfo.tid,
             blkIdx);
 
@@ -1042,6 +1044,8 @@ static int tsdbUpdateSuperBlock(SRWHelper *pHelper, SCompBlock *pCompBlock, int
   pIdx->maxKey = blockAtIdx(pHelper, pIdx->numOfBlocks - 1)->keyLast;
   pIdx->hasLast = (uint32_t)blockAtIdx(pHelper, pIdx->numOfBlocks - 1)->last;
 
+  ASSERT((blkIdx == pIdx->numOfBlocks-1) || (!pCompBlock->last));
+
   tsdbDebug("vgId:%d tid:%d a super block is updated at index %d", REPO_ID(pHelper->pRepo), pHelper->tableInfo.tid,
             blkIdx);
 
@@ -1622,11 +1626,7 @@ static int tsdbProcessMergeCommit(SRWHelper *pHelper, SCommitIter *pCommitIter,
                                   pCfg->update);
 
         if (pDataCols->numOfRows == 0) break;
-        if (tblkIdx == pIdx->numOfBlocks - 1) {
-          if (tsdbWriteBlockToProperFile(pHelper, pDataCols, &compBlock) < 0) return -1;
-        } else {
-          if (tsdbWriteBlockToFile(pHelper, helperDataF(pHelper), pDataCols, &compBlock, false, true) < 0) return -1;
-        }
+        if (tsdbWriteBlockToFile(pHelper, helperDataF(pHelper), pDataCols, &compBlock, false, true) < 0) return -1;
 
         if (round == 0) {
           if (oBlock.last && pHelper->hasOldLastBlock) pHelper->hasOldLastBlock = false;