diff --git a/source/dnode/vnode/src/tsdb/tsdbCommit.c b/source/dnode/vnode/src/tsdb/tsdbCommit.c
index daba81033d..03561ca193 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCommit.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCommit.c
@@ -405,10 +405,6 @@ static int32_t tsdbCommitFileDataStart(SCommitter *pCommitter) {
     }
     wSet.nLastF = pRSet->nLastF + 1;
     wSet.aLastF[wSet.nLastF - 1] = &fLast;  // todo
-
-    if (wSet.nLastF == pCommitter->maxLast) {
-      pCommitter->toMerge = 1;
-    }
   } else {
     fHead = (SHeadFile){.commitID = pCommitter->commitID};
     fData = (SDataFile){.commitID = pCommitter->commitID};
@@ -427,6 +423,9 @@ static int32_t tsdbCommitFileDataStart(SCommitter *pCommitter) {
     wSet.nLastF = 1;
     wSet.aLastF[0] = &fLast;
   }
+  if (wSet.nLastF == pCommitter->maxLast) {
+    pCommitter->toMerge = 1;
+  }
   code = tsdbDataFWriterOpen(&pCommitter->dWriter.pWriter, pTsdb, &wSet);
   if (code) goto _err;
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbMerge.c b/source/dnode/vnode/src/tsdb/tsdbMerge.c
index b804ecf746..3a078131a1 100644
--- a/source/dnode/vnode/src/tsdb/tsdbMerge.c
+++ b/source/dnode/vnode/src/tsdb/tsdbMerge.c
@@ -261,11 +261,13 @@ static int32_t tsdbMergeFileData(STsdbMerger *pMerger, SDFileSet *pSet) {
   // impl
   SRowInfo  rInfo = {.suid = INT64_MIN};
   SRowInfo *pInfo;
+  int64_t   nRow = 0;
   while (true) {
     code = tDataMergeNext(&pMerger->dReader.merger, &pInfo);
     if (code) goto _err;
 
     if (pInfo == NULL) break;
+    nRow++;
 
     ASSERT(tRowInfoCmprFn(pInfo, &rInfo) > 0);
     rInfo = *pInfo;
diff --git a/source/dnode/vnode/src/tsdb/tsdbReaderWriter.c b/source/dnode/vnode/src/tsdb/tsdbReaderWriter.c
index 674e51c9d0..9c4a7aea13 100644
--- a/source/dnode/vnode/src/tsdb/tsdbReaderWriter.c
+++ b/source/dnode/vnode/src/tsdb/tsdbReaderWriter.c
@@ -925,11 +925,11 @@ int32_t tsdbReadLastBlockEx(SDataFReader *pReader, int32_t iLast, SBlockL *pBloc
   int32_t code = 0;
 
   // read
-  code = tsdbReadAndCheck(pReader->aLastFD[iLast], pBlockL->bInfo.offset, &pReader->aBuf[1], pBlockL->bInfo.szBlock, 0);
+  code = tsdbReadAndCheck(pReader->aLastFD[iLast], pBlockL->bInfo.offset, &pReader->aBuf[0], pBlockL->bInfo.szBlock, 0);
   if (code) goto _exit;
 
   // decmpr
-  code = tDecmprBlockData(pReader->aBuf[1], pBlockL->bInfo.szBlock, pBlockData, &pReader->aBuf[1]);
+  code = tDecmprBlockData(pReader->aBuf[0], pBlockL->bInfo.szBlock, pBlockData, &pReader->aBuf[1]);
   if (code) goto _exit;
 
 _exit: