add stddev function partial/merge

source/libs/function/src/builtinsimpl.c

@@ -89,6 +89,7 @@ typedef struct SStddevRes {
     double  dsum;
     int64_t isum;
   };
+  int16_t type;
 } SStddevRes;
 
 typedef struct SLeastSQRInfo {
@@ -1513,6 +1514,7 @@ int32_t stddevFunction(SqlFunctionCtx* pCtx) {
   int32_t               type = pInput->pData[0]->info.type;
 
   SStddevRes* pStddevRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  pStddevRes->type = type;
 
   // computing based on the true data block
   SColumnInfoData* pCol = pInput->pData[0];
@@ -1629,6 +1631,39 @@ _stddev_over:
   return TSDB_CODE_SUCCESS;
 }
 
+static void stddevTransferInfo(SStddevRes* pInput, SStddevRes* pOutput) {
+  pOutput->type = pInput->type;
+  if (IS_INTEGER_TYPE(pOutput->type)) {
+    pOutput->quadraticISum += pInput->quadraticISum;
+    pOutput->isum += pInput->isum;
+  } else {
+    pOutput->quadraticDSum += pInput->quadraticDSum;
+    pOutput->dsum += pInput->dsum;
+  }
+
+  pOutput->count += pInput->count;
+
+  return;
+}
+
+int32_t stddevFunctionMerge(SqlFunctionCtx* pCtx) {
+  SInputColumnInfoData* pInput = &pCtx->input;
+  SColumnInfoData*      pCol = pInput->pData[0];
+  ASSERT(pCol->info.type == TSDB_DATA_TYPE_BINARY);
+
+  SStddevRes* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+
+  int32_t start = pInput->startRowIndex;
+  char*   data = colDataGetData(pCol, start);
+  SStddevRes* pInputInfo = (SStddevRes*)varDataVal(data);
+
+  stddevTransferInfo(pInputInfo, pInfo);
+
+  SET_VAL(GET_RES_INFO(pCtx), 1, 1);
+
+  return TSDB_CODE_SUCCESS;
+}
+
 #define LIST_STDDEV_SUB_N(sumT, T)                                 \
   do {                                                             \
     T* plist = (T*)pCol->pData;                                    \
@@ -1694,9 +1729,10 @@ int32_t stddevInvertFunction(SqlFunctionCtx* pCtx) {
 
 int32_t stddevFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SInputColumnInfoData* pInput = &pCtx->input;
-  int32_t               type = pInput->pData[0]->info.type;
   SStddevRes*           pStddevRes = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  int32_t               type = pStddevRes->type;
   double                avg;
+
   if (IS_INTEGER_TYPE(type)) {
     avg = pStddevRes->isum / ((double)pStddevRes->count);
     pStddevRes->result = sqrt(pStddevRes->quadraticISum / ((double)pStddevRes->count) - avg * avg);
@@ -1708,6 +1744,24 @@ int32_t stddevFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   return functionFinalize(pCtx, pBlock);
 }
 
+int32_t stddevPartialFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
+  SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
+  SStddevRes* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  int32_t  resultBytes = getStddevInfoSize();
+  char*    res = taosMemoryCalloc(resultBytes + VARSTR_HEADER_SIZE, sizeof(char));
+
+  memcpy(varDataVal(res), pInfo, resultBytes);
+  varDataSetLen(res, resultBytes);
+
+  int32_t          slotId = pCtx->pExpr->base.resSchema.slotId;
+  SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, slotId);
+
+  colDataAppend(pCol, pBlock->info.rows, res, false);
+
+  taosMemoryFree(res);
+  return pResInfo->numOfRes;
+}
+
 int32_t stddevCombine(SqlFunctionCtx* pDestCtx, SqlFunctionCtx* pSourceCtx) {
   SResultRowEntryInfo* pDResInfo = GET_RES_INFO(pDestCtx);
   SStddevRes*          pDBuf = GET_ROWCELL_INTERBUF(pDResInfo);