diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index 99177913126b3da573fb9a006171f1dbae686d6b..8f76a3d72f387b993c7ce382543860578d4f051c 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -1273,6 +1273,14 @@ static void doCopyResultToDataBlock(SExprInfo* pExprInfo, int32_t numOfExprs, SR
 
     pCtx[j].resultInfo = getResultEntryInfo(pRow, j, rowEntryOffset);
     if (pCtx[j].fpSet.finalize) {
+      if (strcmp(pCtx[j].pExpr->pExpr->_function.functionName, "_group_key") == 0) {
+        // for groupkey along with functions output multiple lines(e.g. Histogram)
+        // need to fill groupkey result for each output row.
+        if (pCtx[j].resultInfo->numOfRes != 0) {
+          pCtx[j].resultInfo->numOfRes = pRow->numOfRows;
+        }
+      }
+
       int32_t code = pCtx[j].fpSet.finalize(&pCtx[j], pBlock);
       if (TAOS_FAILED(code)) {
         qError("%s build result data block error, code %s", GET_TASKID(pTaskInfo), tstrerror(code));
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index a8d51905ab68ea40c7f35b8aa09116030dca7038..42512d3a11de0b5480d23a96fa463dc3572a370a 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -6157,7 +6157,10 @@ int32_t groupKeyFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SGroupKeyInfo* pInfo = GET_ROWCELL_INTERBUF(pResInfo);
 
   if (pInfo->hasResult) {
-    colDataAppend(pCol, pBlock->info.rows, pInfo->data, pInfo->isNull ? true : false);
+    int32_t currentRow = pBlock->info.rows;
+    for (; currentRow < pBlock->info.rows + pResInfo->numOfRes; ++currentRow) {
+      colDataAppend(pCol, currentRow, pInfo->data, pInfo->isNull ? true : false);
+    }
   } else {
     pResInfo->numOfRes = 0;
   }