diff --git a/source/dnode/vnode/inc/vnode.h b/source/dnode/vnode/inc/vnode.h
index 69c5a6fc805230719044f4806f1801175635e567..f228e83357dd9d937eefe042d62620feb071b180 100644
--- a/source/dnode/vnode/inc/vnode.h
+++ b/source/dnode/vnode/inc/vnode.h
@@ -132,7 +132,10 @@ SArray *tsdbRetrieveDataBlock(STsdbReader *pTsdbReadHandle, SArray *pColumnIdLis
 void    tsdbResetReadHandle(STsdbReader *pReader, SQueryTableDataCond *pCond, int32_t tWinIdx);
 int32_t tsdbGetFileBlocksDistInfo(STsdbReader *pReader, STableBlockDistInfo *pTableBlockInfo);
 int64_t tsdbGetNumOfRowsInMemTable(STsdbReader *pHandle);
-int32_t tsdbRetrieveLastRow(void* pVnode, const SArray* pTableIdList, int32_t type, SSDataBlock* pResBlock);
+
+int32_t tsdbLastRowReaderOpen(void* pVnode, int32_t type, SArray* pTableIdList, int32_t* colId, int32_t numOfCols, void** pReader);
+int32_t tsdbRetrieveLastRow(void* pReader, SSDataBlock* pResBlock, const int32_t* slotIds);
+int32_t tsdbLastrowReaderClose(void* pReader);
 
 // tq
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index 15bacab5fe66a5ee8c07027fd2163e69b90b7a1c..e3eb015c759f45dca83f9e1a4dcada8e11c64d1d 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -18,38 +18,116 @@
 #include "tcommon.h"
 #include "tsdb.h"
 
-// todo parse the stsrow and set the results
-static void keepOneRow(const STSRow* pRow, SSDataBlock* pBlock) {
-  int32_t rowIndex = pBlock->info.rows;
+typedef struct SLastrowReader {
+  SVnode*   pVnode;
+  STSchema* pSchema;
+  uint64_t  uid;
+//  int32_t*  pSlotIds;
+  char**    transferBuf;   // todo remove it soon
+  int32_t   numOfCols;
+  int32_t   type;
+  int32_t   tableIndex;    // currently returned result tables
+  SArray*   pTableList;    // table id list
+} SLastrowReader;
+
+static void saveOneRow(STSRow* pRow, SSDataBlock* pBlock, SLastrowReader* pReader, const int32_t *slotIds) {
+  int32_t numOfRows = pBlock->info.rows;
   size_t  numOfCols = taosArrayGetSize(pBlock->pDataBlock);
+
+  SColVal colVal = {0};
   for (int32_t i = 0; i < numOfCols; ++i) {
     SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
 
-    // todo extract the value of specified column id from STSRow
-    const char* p = NULL;
-    colDataAppend(pColInfoData, rowIndex, p, false);
+    if (slotIds[i] == -1) {
+      colDataAppend(pColInfoData, numOfRows, (const char*)&pRow->ts, false);
+    } else {
+      tTSRowGetVal(pRow, pReader->pSchema, slotIds[i], &colVal);
+
+      if (IS_VAR_DATA_TYPE(colVal.type)) {
+        if (colVal.isNull) {
+          colDataAppendNULL(pColInfoData, numOfRows);
+        } else {
+          varDataSetLen(pReader->transferBuf[i], colVal.value.nData);
+          memcpy(varDataVal(pReader->transferBuf[i]), colVal.value.pData, colVal.value.nData);
+          colDataAppend(pColInfoData, numOfRows, pReader->transferBuf[i], false);
+        }
+      } else {
+        colDataAppend(pColInfoData, numOfRows, (const char*)&colVal.value, colVal.isNull);
+      }
+    }
   }
 
   pBlock->info.rows += 1;
 }
 
-int32_t tsdbRetrieveLastRow(void* pVnode, const SArray* pTableIdList, int32_t type, SSDataBlock* pResBlock) {
-  if (pVnode == NULL || pTableIdList == NULL || pResBlock == NULL) {
+
+int32_t tsdbLastRowReaderOpen(void* pVnode, int32_t type, SArray* pTableIdList, int32_t* colId, int32_t numOfCols, void** pReader) {
+  SLastrowReader* p = taosMemoryCalloc(1, sizeof(SLastrowReader));
+  if (p == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  p->type        = type;
+  p->pVnode      = pVnode;
+  p->numOfCols   = numOfCols;
+  p->transferBuf = taosMemoryCalloc(p->numOfCols, POINTER_BYTES);
+
+  STableKeyInfo* pKeyInfo = taosArrayGet(pTableIdList, 0);
+  p->pSchema     = metaGetTbTSchema(p->pVnode->pMeta, pKeyInfo->uid, -1);
+  p->pTableList  = pTableIdList;
+#if 0
+  for(int32_t i = 0; i < p->numOfCols; ++i) {
+    for(int32_t j = 0; j < p->pSchema->numOfCols; ++j) {
+      if (colId[i] == PRIMARYKEY_TIMESTAMP_COL_ID) {
+        p->pSlotIds[i] = -1;
+        break;
+      }
+
+      if (colId[i] == p->pSchema->columns[j].colId) {
+        p->pSlotIds[i] = j;
+        break;
+      }
+    }
+
+    if (IS_VAR_DATA_TYPE(colId[i])) {
+      p->transferBuf[i] = taosMemoryMalloc(p->pSchema->columns[p->pSlotIds[i]].bytes);
+    }
+  }
+#endif
+  *pReader = p;
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t tsdbLastrowReaderClose(void* pReader) {
+  SLastrowReader* p = pReader;
+
+  for(int32_t i = 0; i < p->numOfCols; ++i) {
+    taosMemoryFreeClear(p->transferBuf[i]);
+  }
+
+  taosMemoryFree(p->transferBuf);
+  taosMemoryFree(pReader);
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t tsdbRetrieveLastRow(void* pReader, SSDataBlock* pResBlock, const int32_t* slotIds) {
+  if (pReader == NULL || pResBlock == NULL) {
     return TSDB_CODE_INVALID_PARA;
   }
 
-  SVnode* pv = pVnode;
+  SLastrowReader* pr = pReader;
+
   STSRow* pRow = NULL;
-  size_t numOfTables = taosArrayGetSize(pTableIdList);
+  size_t numOfTables = taosArrayGetSize(pr->pTableList);
 
   // retrieve the only one last row of all tables in the uid list.
-  if (type == LASTROW_RETRIEVE_TYPE_SINGLE) {
+  if (pr->type == LASTROW_RETRIEVE_TYPE_SINGLE) {
     int64_t lastKey = INT64_MIN;
     bool    internalResult = false;
     for (int32_t i = 0; i < numOfTables; ++i) {
-      STableKeyInfo* pKeyInfo = taosArrayGet(pTableIdList, i);
-
-      int32_t code = tsdbCacheGetLastrow(pv->pTsdb->lruCache, pKeyInfo->uid, pv->pTsdb, &pRow);
+      STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
+      
+      int32_t code = tsdbCacheGetLastrow(pr->pVnode->pTsdb->lruCache, pKeyInfo->uid, pr->pVnode->pTsdb, &pRow);
       if (code != TSDB_CODE_SUCCESS) {
         return code;
       }
@@ -65,16 +143,16 @@ int32_t tsdbRetrieveLastRow(void* pVnode, const SArray* pTableIdList, int32_t ty
           pResBlock->info.rows -= 1;
         }
 
-        keepOneRow(pRow, pResBlock);
+        saveOneRow(pRow, pResBlock, pr, slotIds);
         internalResult = true;
         lastKey = pRow->ts;
       }
     }
-  } else if (type == LASTROW_RETRIEVE_TYPE_ALL) {
-    for (int32_t i = 0; i < numOfTables; ++i) {
-      STableKeyInfo* pKeyInfo = taosArrayGet(pTableIdList, i);
+  } else if (pr->type == LASTROW_RETRIEVE_TYPE_ALL) {
+    for (int32_t i = pr->tableIndex; i < numOfTables; ++i) {
+      STableKeyInfo* pKeyInfo = taosArrayGet(pr->pTableList, i);
 
-      int32_t code = tsdbCacheGetLastrow(pv->pTsdb->lruCache, pKeyInfo->uid, pv->pTsdb, &pRow);
+      int32_t code = tsdbCacheGetLastrow(pr->pVnode->pTsdb->lruCache, pKeyInfo->uid, pr->pVnode->pTsdb, &pRow);
       if (code != TSDB_CODE_SUCCESS) {
         return code;
       }
@@ -84,7 +162,12 @@ int32_t tsdbRetrieveLastRow(void* pVnode, const SArray* pTableIdList, int32_t ty
         continue;
       }
 
-      keepOneRow(pRow, pResBlock);
+      saveOneRow(pRow, pResBlock, pr, slotIds);
+
+      pr->tableIndex += 1;
+      if (pResBlock->info.rows >= pResBlock->info.capacity) {
+        return TSDB_CODE_SUCCESS;
+      }
     }
   } else {
     return TSDB_CODE_INVALID_PARA;
diff --git a/source/libs/executor/inc/executorimpl.h b/source/libs/executor/inc/executorimpl.h
index b947c560c661149216bd1b548f2bc01f2e340f0c..d1299b65f9ff738c9611ce17a1c5f96cf57b2ccf 100644
--- a/source/libs/executor/inc/executorimpl.h
+++ b/source/libs/executor/inc/executorimpl.h
@@ -142,8 +142,8 @@ typedef struct SExecTaskInfo {
   struct {
     char          *tablename;
     char          *dbname;
-    int32_t        sversion;
     int32_t        tversion;
+    SSchemaWrapper*sw;
   } schemaVer;
 
   STableListInfo   tableqinfoList;       // this is a table list
@@ -296,6 +296,9 @@ typedef struct SLastrowScanInfo {
   SSDataBlock    *pRes;
   SArray         *pTableList;
   SReadHandle     readHandle;
+  void           *pLastrowReader;
+  SArray         *pColMatchInfo;
+  int32_t        *pSlotIds;
 } SLastrowScanInfo;
 
 typedef enum EStreamScanMode {
diff --git a/source/libs/executor/src/executor.c b/source/libs/executor/src/executor.c
index 6de364e63a3c2bbe6e5044a53a7f916b1d2d8da1..9cf6be5eef12c13f03f56ad4a057b4a80873d3b5 100644
--- a/source/libs/executor/src/executor.c
+++ b/source/libs/executor/src/executor.c
@@ -187,7 +187,7 @@ int32_t qGetQueriedTableSchemaVersion(qTaskInfo_t tinfo, char* dbName, char* tab
   ASSERT(tinfo != NULL && dbName != NULL && tableName != NULL);
   SExecTaskInfo* pTaskInfo = (SExecTaskInfo*)tinfo;
 
-  *sversion = pTaskInfo->schemaVer.sversion;
+  *sversion = pTaskInfo->schemaVer.sw->version;
   *tversion = pTaskInfo->schemaVer.tversion;
   if (pTaskInfo->schemaVer.dbname) {
     strcpy(dbName, pTaskInfo->schemaVer.dbname);
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index 0d84d67d7e452a1df06528af5187db11dc6be7c6..570dea474ae9c34c64c769af052e149c50e9884d 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -13,6 +13,8 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <executorimpl.h>
+#include <vnode.h>
 #include "filter.h"
 #include "function.h"
 #include "functionMgt.h"
@@ -2803,7 +2805,7 @@ int32_t getTableScanInfo(SOperatorInfo* pOperator, int32_t* order, int32_t* scan
   int32_t type = pOperator->operatorType;
   if (type == QUERY_NODE_PHYSICAL_PLAN_EXCHANGE || type == QUERY_NODE_PHYSICAL_PLAN_SYSTABLE_SCAN ||
       type == QUERY_NODE_PHYSICAL_PLAN_STREAM_SCAN || type == QUERY_NODE_PHYSICAL_PLAN_TAG_SCAN ||
-      type == QUERY_NODE_PHYSICAL_PLAN_BLOCK_DIST_SCAN) {
+      type == QUERY_NODE_PHYSICAL_PLAN_BLOCK_DIST_SCAN || type == QUERY_NODE_PHYSICAL_PLAN_LAST_ROW_SCAN) {
     *order = TSDB_ORDER_ASC;
     *scanFlag = MAIN_SCAN;
     return TSDB_CODE_SUCCESS;
@@ -3886,15 +3888,15 @@ int32_t extractTableSchemaVersion(SReadHandle* pHandle, uint64_t uid, SExecTaskI
   pTaskInfo->schemaVer.tablename = strdup(mr.me.name);
 
   if (mr.me.type == TSDB_SUPER_TABLE) {
-    pTaskInfo->schemaVer.sversion = mr.me.stbEntry.schemaRow.version;
+    pTaskInfo->schemaVer.sw = tCloneSSchemaWrapper(&mr.me.stbEntry.schemaRow);
     pTaskInfo->schemaVer.tversion = mr.me.stbEntry.schemaTag.version;
   } else if (mr.me.type == TSDB_CHILD_TABLE) {
     tb_uid_t suid = mr.me.ctbEntry.suid;
     metaGetTableEntryByUid(&mr, suid);
-    pTaskInfo->schemaVer.sversion = mr.me.stbEntry.schemaRow.version;
+    pTaskInfo->schemaVer.sw = tCloneSSchemaWrapper(&mr.me.stbEntry.schemaRow);
     pTaskInfo->schemaVer.tversion = mr.me.stbEntry.schemaTag.version;
   } else {
-    pTaskInfo->schemaVer.sversion = mr.me.ntbEntry.schemaRow.version;
+    pTaskInfo->schemaVer.sw = tCloneSSchemaWrapper(&mr.me.ntbEntry.schemaRow);
   }
 
   metaReaderClear(&mr);
@@ -4177,9 +4179,11 @@ SOperatorInfo* createOperatorTree(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo
 //        return NULL;
 //      }
 
+      int32_t code = extractTableSchemaVersion(pHandle, pScanNode->uid, pTaskInfo);
+
       pTableListInfo->pTableList = taosArrayInit(4, sizeof(STableKeyInfo));
       if (pScanNode->tableType == TSDB_SUPER_TABLE) {
-        int32_t code = vnodeGetAllTableList(pHandle->meta, pScanNode->uid, pTableListInfo->pTableList);
+        code = vnodeGetAllTableList(pHandle->meta, pScanNode->uid, pTableListInfo->pTableList);
         if (code != TSDB_CODE_SUCCESS) {
           pTaskInfo->code = terrno;
           return NULL;
diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index f2b1725fb38641067330c77547f5b4a110fb7596..bb3f4e403d50009bd76f7ab97740101509c73001 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -13,13 +13,12 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "filter.h"
+#include "executorimpl.h"
 #include "function.h"
 #include "functionMgt.h"
 #include "os.h"
 #include "querynodes.h"
 #include "systable.h"
-#include "tglobal.h"
 #include "tname.h"
 #include "ttime.h"
 
@@ -33,8 +32,6 @@
 #include "ttypes.h"
 #include "vnode.h"
 
-#include "executorInt.h"
-
 #define SET_REVERSE_SCAN_FLAG(_info) ((_info)->scanFlag = REVERSE_SCAN)
 #define SWITCH_ORDER(n)              (((n) = ((n) == TSDB_ORDER_ASC) ? TSDB_ORDER_DESC : TSDB_ORDER_ASC))
 
@@ -2537,7 +2534,8 @@ static SSDataBlock* doScanLastrow(SOperatorInfo* pOperator) {
 
   // check if it is a group by tbname
   if (size == taosArrayGetSize(pInfo->pTableList)) {
-    tsdbRetrieveLastRow(pInfo->readHandle.vnode, pInfo->pTableList, LASTROW_RETRIEVE_TYPE_ALL, pInfo->pRes);
+    blockDataCleanup(pInfo->pRes);
+    tsdbRetrieveLastRow(pInfo->pLastrowReader, pInfo->pRes, pInfo->pSlotIds);
     return (pInfo->pRes->info.rows == 0)? NULL:pInfo->pRes;
   } else {
     //todo fetch the result for each group
@@ -2550,9 +2548,10 @@ static SSDataBlock* doScanLastrow(SOperatorInfo* pOperator) {
 static void destroyLastrowScanOperator(void* param, int32_t numOfOutput) {
   SLastrowScanInfo* pInfo = (SLastrowScanInfo*) param;
   blockDataDestroy(pInfo->pRes);
+  tsdbLastrowReaderClose(pInfo->pLastrowReader);
 }
 
-SOperatorInfo* createLastrowScanOperator(SLastRowScanPhysiNode* pTableScanNode, SReadHandle* readHandle,
+SOperatorInfo* createLastrowScanOperator(SLastRowScanPhysiNode* pScanNode, SReadHandle* readHandle,
                                          SArray* pTableList, SExecTaskInfo* pTaskInfo) {
   SLastrowScanInfo* pInfo = taosMemoryCalloc(1, sizeof(SLastrowScanInfo));
   SOperatorInfo*    pOperator = taosMemoryCalloc(1, sizeof(SOperatorInfo));
@@ -2562,7 +2561,34 @@ SOperatorInfo* createLastrowScanOperator(SLastRowScanPhysiNode* pTableScanNode,
 
   pInfo->pTableList = pTableList;
   pInfo->readHandle = *readHandle;
-  pInfo->pRes = createResDataBlock(pTableScanNode->node.pOutputDataBlockDesc);
+  pInfo->pRes = createResDataBlock(pScanNode->node.pOutputDataBlockDesc);
+
+  int32_t numOfCols = 0;
+  pInfo->pColMatchInfo = extractColMatchInfo(pScanNode->pScanCols, pScanNode->node.pOutputDataBlockDesc, &numOfCols, COL_MATCH_FROM_COL_ID);
+  int32_t* pCols = taosMemoryMalloc(numOfCols * sizeof(int32_t));
+  for(int32_t i = 0; i < numOfCols; ++i) {
+    SColMatchInfo* pColMatch = taosArrayGet(pInfo->pColMatchInfo, i);
+    pCols[i] = pColMatch->colId;
+  }
+
+  pInfo->pSlotIds = taosMemoryMalloc(numOfCols * sizeof(pInfo->pSlotIds[0]));
+  for(int32_t i = 0; i < numOfCols; ++i) {
+    SColMatchInfo* pColMatch = taosArrayGet(pInfo->pColMatchInfo, i);
+    for(int32_t j = 0; j < pTaskInfo->schemaVer.sw->nCols; ++j) {
+      if (pColMatch->colId == pTaskInfo->schemaVer.sw->pSchema[j].colId && pColMatch->colId == PRIMARYKEY_TIMESTAMP_COL_ID) {
+        pInfo->pSlotIds[pColMatch->targetSlotId] = -1;
+        break;
+      }
+
+      if (pColMatch->colId == pTaskInfo->schemaVer.sw->pSchema[j].colId) {
+        pInfo->pSlotIds[pColMatch->targetSlotId] = j;
+        break;
+      }
+    }
+  }
+
+  tsdbLastRowReaderOpen(readHandle->vnode, LASTROW_RETRIEVE_TYPE_ALL, pTableList, pCols, numOfCols, &pInfo->pLastrowReader);
+  taosMemoryFree(pCols);
 
   pOperator->name         = "LastrowScanOperator";
   pOperator->operatorType = QUERY_NODE_PHYSICAL_PLAN_LAST_ROW_SCAN;
@@ -2570,8 +2596,10 @@ SOperatorInfo* createLastrowScanOperator(SLastRowScanPhysiNode* pTableScanNode,
   pOperator->status       = OP_NOT_OPENED;
   pOperator->info         = pInfo;
   pOperator->pTaskInfo    = pTaskInfo;
+  pOperator->exprSupp.numOfExprs = taosArrayGetSize(pInfo->pRes->pDataBlock);
 
   initResultSizeInfo(pOperator, 1024);
+  blockDataEnsureCapacity(pInfo->pRes, pOperator->resultInfo.capacity);
 
   pOperator->fpSet =
       createOperatorFpSet(operatorDummyOpenFn, doScanLastrow, NULL, NULL, destroyLastrowScanOperator,
diff --git a/source/libs/function/inc/builtinsimpl.h b/source/libs/function/inc/builtinsimpl.h
index 0820e884cea1f81d6576d609dc91bba65447e6c7..bba4086960286b5d80e784438b8b593b220c460f 100644
--- a/source/libs/function/inc/builtinsimpl.h
+++ b/source/libs/function/inc/builtinsimpl.h
@@ -106,6 +106,8 @@ bool irateFuncSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResInfo);
 int32_t irateFunction(SqlFunctionCtx *pCtx);
 int32_t irateFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock);
 
+int32_t lastrowFunction(SqlFunctionCtx* pCtx);
+
 bool getFirstLastFuncEnv(struct SFunctionNode* pFunc, SFuncExecEnv* pEnv);
 int32_t firstFunction(SqlFunctionCtx *pCtx);
 int32_t firstFunctionMerge(SqlFunctionCtx *pCtx);
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index d41bc89a5fe61d65e9890c24eeac8a257182d931..4bf9d8fcc125d4ab78590bc9e7b605929c1d5adf 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -1873,11 +1873,11 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .name = "last_row",
     .type = FUNCTION_TYPE_LAST_ROW,
     .classification = FUNC_MGT_AGG_FUNC | FUNC_MGT_MULTI_RES_FUNC | FUNC_MGT_TIMELINE_FUNC,
-    .translateFunc = translateLastRow,
-    .getEnvFunc   = getMinmaxFuncEnv,
-    .initFunc     = minmaxFunctionSetup,
-    .processFunc  = maxFunction,
-    .finalizeFunc = functionFinalize
+    .translateFunc = translateFirstLast,
+    .getEnvFunc   = getFirstLastFuncEnv,
+    .initFunc     = functionSetup,
+    .processFunc  = lastrowFunction,
+    .finalizeFunc = firstLastFinalize
   },
   {
     .name = "first",
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index c4d3a26ab4244c4d6dab96aa3fb0d82cac878153..93a117aec9d0332166dd9a3f385bd44c026e7e85 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -5503,3 +5503,43 @@ int32_t interpFunction(SqlFunctionCtx* pCtx) {
 
   return TSDB_CODE_SUCCESS;
 }
+
+int32_t lastrowFunction(SqlFunctionCtx* pCtx) {
+  int32_t numOfElems = 0;
+
+  SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
+  SFirstLastRes*       pInfo = GET_ROWCELL_INTERBUF(pResInfo);
+
+  SInputColumnInfoData* pInput = &pCtx->input;
+  SColumnInfoData*      pInputCol = pInput->pData[0];
+
+  int32_t type = pInputCol->info.type;
+  int32_t bytes = pInputCol->info.bytes;
+  pInfo->bytes = bytes;
+
+  for (int32_t i = pInput->numOfRows + pInput->startRowIndex - 1; i >= pInput->startRowIndex; --i) {
+    if (pInputCol->hasNull && colDataIsNull_s(pInputCol, i)) {
+      continue;
+    }
+
+    numOfElems++;
+
+    char* data = colDataGetData(pInputCol, i);
+    TSKEY cts = getRowPTs(pInput->pPTS, i);
+    if (pResInfo->numOfRes == 0 || *(TSKEY*)(pInfo->buf + bytes) < cts) {
+      if (IS_VAR_DATA_TYPE(type)) {
+        bytes = varDataTLen(data);
+        pInfo->bytes = bytes;
+      }
+
+      memcpy(pInfo->buf, data, bytes);
+      *(TSKEY*)(pInfo->buf + bytes) = cts;
+
+      pInfo->hasResult = true;
+      pResInfo->numOfRes = 1;
+    }
+  }
+
+  SET_VAL(pResInfo, numOfElems, 1);
+  return TSDB_CODE_SUCCESS;
+}