From 673d3bc376ad8955bd4b3b9163853eebb983b915 Mon Sep 17 00:00:00 2001
From: Bob Liu <bobliu@taosdata.com>
Date: Sun, 31 Dec 2023 13:15:05 +0800
Subject: [PATCH] arrangeTableGroup

---
 source/libs/executor/src/executil.c | 70 +++++++++++++++++++++++++++++
 source/libs/executor/src/operator.c |  2 +-
 2 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/source/libs/executor/src/executil.c b/source/libs/executor/src/executil.c
index 4b3b1ffead..f3e2e99332 100644
--- a/source/libs/executor/src/executil.c
+++ b/source/libs/executor/src/executil.c
@@ -2116,6 +2116,70 @@ static int32_t sortTableGroup(STableListInfo* pTableListInfo) {
   return TSDB_CODE_SUCCESS;
 }
 
+static int32_t arrangeTableGroup(STableListInfo* pTableListInfo) {
+  int32_t code = TSDB_CODE_SUCCESS;
+  size_t    numOfTables = taosArrayGetSize(pTableListInfo->pTableList);
+  SArray*   pDup = NULL;
+  SHashObj* pHashObj = taosHashInit(numOfTables, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, HASH_NO_LOCK);
+  if (!pHashObj) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+  int32_t   num = 1;
+  // first: get the number of tables per group
+  for (int32_t i = 0; i < numOfTables; ++i) {
+    STableKeyInfo* pInfo = taosArrayGet(pTableListInfo->pTableList, i);
+    int32_t*       pVal = taosHashGet(pHashObj, &pInfo->groupId, sizeof(pInfo->groupId));
+    // update each group's table count
+    if (!pVal) {
+      taosHashPut(pHashObj, &pInfo->groupId, sizeof(pInfo->groupId), &num, sizeof(num));
+    } else {
+      (*pVal)++;
+    }
+  }
+  pTableListInfo->numOfOuputGroups = taosHashGetSize(pHashObj);
+  pTableListInfo->oneTableForEachGroup = (pTableListInfo->numOfOuputGroups == numOfTables);
+
+  if (pTableListInfo->numOfOuputGroups > 1 && pTableListInfo->numOfOuputGroups < numOfTables) {
+    pDup = taosArrayDup(pTableListInfo->pTableList, NULL);
+    pTableListInfo->groupOffset = taosMemoryMalloc(sizeof(int32_t) * pTableListInfo->numOfOuputGroups);
+    if (pDup == NULL || pTableListInfo->groupOffset == NULL) {
+      code = TSDB_CODE_OUT_OF_MEMORY;
+      goto _exit;
+    }
+    int32_t idx = 0, sum = 0;
+
+    void* pIter = taosHashIterate(pHashObj, NULL);
+    while (pIter != NULL) {
+      // record each group's offset
+      pTableListInfo->groupOffset[idx] = sum;
+      int32_t* pData = (int32_t*)pIter;
+      sum += *pData;
+      // change value to record group item's first position
+      *pData = pTableListInfo->groupOffset[idx++];
+      pIter = taosHashIterate(pHashObj, pIter);
+    }
+
+    // second: arrange the tables and put the items with same groupId together
+    STableKeyInfo* pStart = taosArrayGet(pTableListInfo->pTableList, 0);
+    for (int32_t i = 0; i < numOfTables; ++i) {
+      STableKeyInfo* pInfo = taosArrayGet(pDup, i);
+      int32_t*       pVal = taosHashGet(pHashObj, &pInfo->groupId, sizeof(pInfo->groupId));
+      if (*pVal != i) {
+        pStart[*pVal] = *pInfo;
+      }
+      (*pVal)++;  // update to next item's position
+    }
+  }
+
+_exit:
+  taosHashCleanup(pHashObj);
+  taosArrayDestroy(pDup);
+  if (code != TSDB_CODE_SUCCESS) {
+    taosMemoryFreeClear(pTableListInfo->groupOffset);
+  }
+  return code;
+}
+
 int32_t buildGroupIdMapForAllTables(STableListInfo* pTableListInfo, SReadHandle* pHandle, SScanPhysiNode* pScanNode,
                                     SNodeList* group, bool groupSort, uint8_t* digest, SStorageAPI* pAPI) {
   int32_t code = TSDB_CODE_SUCCESS;
@@ -2149,6 +2213,12 @@ int32_t buildGroupIdMapForAllTables(STableListInfo* pTableListInfo, SReadHandle*
 
     if (groupSort || pScanNode->groupOrderScan) {
       code = sortTableGroup(pTableListInfo);
+    } else if (QUERY_NODE_PHYSICAL_PLAN_TABLE_SCAN == nodeType(pScanNode)) {
+      STableScanPhysiNode* pTableScanNode = (STableScanPhysiNode*)pScanNode;
+      if (pTableScanNode->needCountEmptyTable) {
+        // only put together tables with the same groupid
+        arrangeTableGroup(pTableListInfo);
+      }
     }
   }
 
diff --git a/source/libs/executor/src/operator.c b/source/libs/executor/src/operator.c
index 0b5e7f51ed..69a8acb3d7 100644
--- a/source/libs/executor/src/operator.c
+++ b/source/libs/executor/src/operator.c
@@ -302,7 +302,7 @@ SOperatorInfo* createOperator(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo, SR
         pTableListInfo->idInfo.suid = pTableScanNode->scan.suid;
         pTableListInfo->idInfo.tableType = pTableScanNode->scan.tableType;
       } else {
-        code = createScanTableListInfo(&pTableScanNode->scan, pTableScanNode->pGroupTags, true, pHandle,
+        code = createScanTableListInfo(&pTableScanNode->scan, pTableScanNode->pGroupTags, pTableScanNode->groupSort, pHandle,
                                     pTableListInfo, pTagCond, pTagIndexCond, pTaskInfo);
         if (code) {
           pTaskInfo->code = code;