diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index 3d8b2a40318fa136a47bff1589f8707e28a246f4..1906ae1abd9f69025b9ff09953f85d1c8b31f7fb 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -177,15 +177,15 @@ struct STsdbReader {
   SBlockLoadSuppInfo suppInfo;
   STsdbReadSnap*     pReadSnap;
   SIOCostSummary     cost;
-  STSchema*          pSchema;      // the newest version schema
-//  STSchema*          pMemSchema;   // the previous schema for in-memory data, to avoid load schema too many times
-  SSHashObj*         pSchemaMap;   // keep the retrieved schema info, to avoid the overhead by repeatly load schema
-  SDataFReader*      pFileReader;  // the file reader
-  SDelFReader*       pDelFReader;  // the del file reader
-  SArray*            pDelIdx;      // del file block index;
-  SBlockInfoBuf      blockInfoBuf;
-  int32_t            step;
-  STsdbReader*       innerReader[2];
+  STSchema*          pSchema;  // the newest version schema
+  //  STSchema*          pMemSchema;   // the previous schema for in-memory data, to avoid load schema too many times
+  SSHashObj*    pSchemaMap;   // keep the retrieved schema info, to avoid the overhead by repeatly load schema
+  SDataFReader* pFileReader;  // the file reader
+  SDelFReader*  pDelFReader;  // the del file reader
+  SArray*       pDelIdx;      // del file block index;
+  SBlockInfoBuf blockInfoBuf;
+  int32_t       step;
+  STsdbReader*  innerReader[2];
 };
 
 static SFileDataBlockInfo* getCurrentBlockInfo(SDataBlockIter* pBlockIter);
@@ -1862,11 +1862,11 @@ static FORCE_INLINE STSchema* doGetSchemaForTSRow(int32_t sversion, STsdbReader*
 
   void** p = tSimpleHashGet(pReader->pSchemaMap, &sversion, sizeof(sversion));
   if (p != NULL) {
-    return *(STSchema**) p;
+    return *(STSchema**)p;
   }
 
   STSchema* ptr = NULL;
-  int32_t code = metaGetTbTSchemaEx(pReader->pTsdb->pVnode->pMeta, pReader->suid, uid, sversion, &ptr);
+  int32_t   code = metaGetTbTSchemaEx(pReader->pTsdb->pVnode->pMeta, pReader->suid, uid, sversion, &ptr);
   if (code != TSDB_CODE_SUCCESS) {
     terrno = code;
     return NULL;
@@ -3674,8 +3674,9 @@ int32_t doMergeMemIMemRows(TSDBROW* pRow, TSDBROW* piRow, STableBlockScanInfo* p
 
   if (ASCENDING_TRAVERSE(pReader->order)) {  // ascending order imem --> mem
     STSchema* pSchema = doGetSchemaForTSRow(TSDBROW_SVERSION(pRow), pReader, pBlockScanInfo->uid);
+    STSchema* piSchema = doGetSchemaForTSRow(TSDBROW_SVERSION(piRow), pReader, pBlockScanInfo->uid);
 
-    int32_t code = tsdbRowMergerInit(&merge, piRow, pSchema);
+    int32_t code = tsdbRowMergerInit2(&merge, pSchema, piRow, piSchema);
     if (code != TSDB_CODE_SUCCESS) {
       return code;
     }
@@ -4000,7 +4001,7 @@ static int32_t doOpenReaderImpl(STsdbReader* pReader) {
 }
 
 static void freeSchemaFunc(void* param) {
-  void* p = *(void**) param;
+  void* p = *(void**)param;
   taosMemoryFree(p);
 }
 
@@ -4082,7 +4083,7 @@ int32_t tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, void* pTableL
 
   pReader->pSchemaMap = tSimpleHashInit(8, taosFastHash);
   if (pReader->pSchemaMap == NULL) {
-    tsdbError("failed init schema hash for reader", pReader->idStr);
+    tsdbError("failed init schema hash for reader %s", pReader->idStr);
     code = TSDB_CODE_OUT_OF_MEMORY;
     goto _err;
   }
@@ -4710,7 +4711,7 @@ int32_t tsdbReaderReset(STsdbReader* pReader, SQueryTableDataCond* pCond) {
     return TSDB_CODE_SUCCESS;
   }
 
-  SReaderStatus* pStatus = &pReader->status;
+  SReaderStatus*  pStatus = &pReader->status;
   SDataBlockIter* pBlockIter = &pStatus->blockIter;
 
   pReader->order = pCond->order;
@@ -4731,9 +4732,9 @@ int32_t tsdbReaderReset(STsdbReader* pReader, SQueryTableDataCond* pCond) {
   resetDataBlockIterator(pBlockIter, pReader->order);
   resetTableListIndex(&pReader->status);
 
-  bool asc = ASCENDING_TRAVERSE(pReader->order);
-  int32_t step = asc? 1:-1;
-  int64_t ts = asc? pReader->window.skey - 1 : pReader->window.ekey + 1;
+  bool    asc = ASCENDING_TRAVERSE(pReader->order);
+  int32_t step = asc ? 1 : -1;
+  int64_t ts = asc ? pReader->window.skey - 1 : pReader->window.ekey + 1;
   resetAllDataBlockScanInfo(pStatus->pTableMap, ts, step);
 
   int32_t code = 0;