diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 059a3a2d835eda364084672766311345ec0aa810..158cf2a0c39797b3864e79b4a1d5bd587ebc7f59 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -418,31 +418,16 @@ typedef enum {
 } SFSLASTNEXTROWSTATES;
 
 typedef struct {
-  SFSLASTNEXTROWSTATES state;         // [input]
-  STsdb               *pTsdb;         // [input]
-  SBlockIdx           *pBlockIdxExp;  // [input]
-  STSchema            *pTSchema;      // [input]
-  tb_uid_t             suid;
+  SFSLASTNEXTROWSTATES state;  // [input]
+  STsdb               *pTsdb;  // [input]
   tb_uid_t             uid;
   int32_t              nFileSet;
   int32_t              iFileSet;
   SArray              *aDFileSet;
   SDataFReader        *pDataFReader;
-  SArray              *aBlockL;
-  SBlockL             *pBlockL;
-  SBlockData          *pBlockDataL;
-  SBlockData           blockDataL;
-  int32_t              nRow;
-  int32_t              iRow;
   TSDBROW              row;
-  /*
-  SArray    *aBlockIdx;
-  SBlockIdx *pBlockIdx;
-  SMapData   blockMap;
-  int32_t    nBlock;
-  int32_t    iBlock;
-  SBlock     block;
-  */
+
+  SMergeTree mergeTree;
 } SFSLastNextRowIter;
 
 static int32_t getNextRowFromFSLast(void *iter, TSDBROW **ppRow) {
@@ -451,22 +436,16 @@ static int32_t getNextRowFromFSLast(void *iter, TSDBROW **ppRow) {
 
   switch (state->state) {
     case SFSLASTNEXTROW_FS:
-      // state->aDFileSet = state->pTsdb->pFS->cState->aDFileSet;
       state->nFileSet = taosArrayGetSize(state->aDFileSet);
       state->iFileSet = state->nFileSet;
 
-      state->pBlockDataL = NULL;
-
     case SFSLASTNEXTROW_FILESET: {
       SDFileSet *pFileSet = NULL;
     _next_fileset:
       if (--state->iFileSet >= 0) {
         pFileSet = (SDFileSet *)taosArrayGet(state->aDFileSet, state->iFileSet);
       } else {
-        if (state->pBlockDataL) {
-          tBlockDataDestroy(state->pBlockDataL, 1);
-          state->pBlockDataL = NULL;
-        }
+        // tMergeTreeClose(&state->mergeTree);
 
         *ppRow = NULL;
         return code;
@@ -475,68 +454,24 @@ static int32_t getNextRowFromFSLast(void *iter, TSDBROW **ppRow) {
       code = tsdbDataFReaderOpen(&state->pDataFReader, state->pTsdb, pFileSet);
       if (code) goto _err;
 
-      if (!state->aBlockL) {
-        state->aBlockL = taosArrayInit(0, sizeof(SBlockL));
-      } else {
-        taosArrayClear(state->aBlockL);
-      }
-
-      code = tsdbReadBlockL(state->pDataFReader, 0, state->aBlockL);
-      if (code) goto _err;
-
-      // SBlockL *pBlockL = (SBlockL *)taosArrayGet(state->aBlockL, state->iBlockL);
-
-      state->pBlockL = taosArraySearch(state->aBlockL, state->pBlockIdxExp, tCmprBlockL, TD_EQ);
-      if (!state->pBlockL) {
+      tMergeTreeOpen(&state->mergeTree, 1, state->pDataFReader, state->uid,
+                     &(STimeWindow){.skey = TSKEY_MIN, .ekey = TSKEY_MAX},
+                     &(SVersionRange){.minVer = 0, .maxVer = UINT64_MAX});
+      bool hasVal = tMergeTreeNext(&state->mergeTree);
+      if (!hasVal) {
+        state->state = SFSLASTNEXTROW_FILESET;
+        // tMergeTreeClose(&state->mergeTree);
         goto _next_fileset;
       }
-
-      int64_t suid = state->pBlockL->suid;
-      int64_t uid = state->pBlockL->maxUid;
-
-      if (!state->pBlockDataL) {
-        state->pBlockDataL = &state->blockDataL;
-
-        tBlockDataCreate(state->pBlockDataL);
-      }
-      code = tBlockDataInit(state->pBlockDataL, suid, suid ? 0 : uid, state->pTSchema);
-      if (code) goto _err;
-    }
-    case SFSLASTNEXTROW_BLOCKDATA:
-      code = tsdbReadLastBlock(state->pDataFReader, 0, state->pBlockL, state->pBlockDataL);
-      if (code) goto _err;
-
-      state->nRow = state->blockDataL.nRow;
-      state->iRow = state->nRow - 1;
-
-      if (!state->pBlockDataL->uid) {
-        while (state->pBlockIdxExp->uid != state->pBlockDataL->aUid[state->iRow]) {
-          --state->iRow;
-        }
-      }
-
       state->state = SFSLASTNEXTROW_BLOCKROW;
+    }
     case SFSLASTNEXTROW_BLOCKROW:
-      if (state->pBlockDataL->uid) {
-        if (state->iRow >= 0) {
-          state->row = tsdbRowFromBlockData(state->pBlockDataL, state->iRow);
-          *ppRow = &state->row;
-
-          if (--state->iRow < 0) {
-            state->state = SFSLASTNEXTROW_FILESET;
-          }
-        }
-      } else {
-        if (state->iRow >= 0 && state->pBlockIdxExp->uid == state->pBlockDataL->aUid[state->iRow]) {
-          state->row = tsdbRowFromBlockData(state->pBlockDataL, state->iRow);
-          *ppRow = &state->row;
-
-          if (--state->iRow < 0 || state->pBlockIdxExp->uid != state->pBlockDataL->aUid[state->iRow]) {
-            state->state = SFSLASTNEXTROW_FILESET;
-          }
-        }
+      state->row = tMergeTreeGetRow(&state->mergeTree);
+      *ppRow = &state->row;
+      bool hasVal = tMergeTreeNext(&state->mergeTree);
+      if (!hasVal) {
+        state->state = SFSLASTNEXTROW_FILESET;
       }
-
       return code;
     default:
       ASSERT(0);
@@ -548,15 +483,6 @@ _err:
     tsdbDataFReaderClose(&state->pDataFReader);
     state->pDataFReader = NULL;
   }
-  if (state->aBlockL) {
-    taosArrayDestroy(state->aBlockL);
-    state->aBlockL = NULL;
-  }
-  if (state->pBlockDataL) {
-    tBlockDataDestroy(state->pBlockDataL, 1);
-    state->pBlockDataL = NULL;
-  }
-
   *ppRow = NULL;
 
   return code;
@@ -574,14 +500,6 @@ int32_t clearNextRowFromFSLast(void *iter) {
     tsdbDataFReaderClose(&state->pDataFReader);
     state->pDataFReader = NULL;
   }
-  if (state->aBlockL) {
-    taosArrayDestroy(state->aBlockL);
-    state->aBlockL = NULL;
-  }
-  if (state->pBlockDataL) {
-    tBlockDataDestroy(state->pBlockDataL, 1);
-    state->pBlockDataL = NULL;
-  }
 
   return code;
 }
@@ -972,9 +890,6 @@ static int32_t nextRowIterOpen(CacheNextRowIter *pIter, tb_uid_t uid, STsdb *pTs
   pIter->fsLastState.state = (SFSLASTNEXTROWSTATES)SFSNEXTROW_FS;
   pIter->fsLastState.pTsdb = pTsdb;
   pIter->fsLastState.aDFileSet = pIter->pReadSnap->fs.aDFileSet;
-  pIter->fsLastState.pBlockIdxExp = &pIter->idx;
-  pIter->fsLastState.pTSchema = pTSchema;
-  pIter->fsLastState.suid = suid;
   pIter->fsLastState.uid = uid;
 
   pIter->fsState.state = SFSNEXTROW_FS;