From 12759683ca92020aae8bd7092a71165f542cc9ce Mon Sep 17 00:00:00 2001
From: Xiaoyu Wang <xiaoyuwang@taosdata.com>
Date: Mon, 11 Jul 2022 18:23:54 +0800
Subject: [PATCH] fix: some problems of 'partition by' execution plan

---
 source/libs/planner/src/planLogicCreater.c  |  4 ++--
 source/libs/planner/src/planOptimizer.c     |  3 ++-
 source/libs/planner/src/planSpliter.c       | 21 ++++++++++++++++++++-
 source/libs/planner/test/planPartByTest.cpp |  2 ++
 4 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/source/libs/planner/src/planLogicCreater.c b/source/libs/planner/src/planLogicCreater.c
index cb38e1fc18..e90be75743 100644
--- a/source/libs/planner/src/planLogicCreater.c
+++ b/source/libs/planner/src/planLogicCreater.c
@@ -476,12 +476,12 @@ static int32_t createAggLogicNode(SLogicPlanContext* pCxt, SSelectStmt* pSelect,
   int32_t code = TSDB_CODE_SUCCESS;
 
   // set grouyp keys, agg funcs and having conditions
-  if (TSDB_CODE_SUCCESS == code && pSelect->hasAggFuncs) {
+  if (TSDB_CODE_SUCCESS == code) {
     code = nodesCollectFuncs(pSelect, SQL_CLAUSE_GROUP_BY, fmIsAggFunc, &pAgg->pAggFuncs);
   }
 
   // rewrite the expression in subsequent clauses
-  if (TSDB_CODE_SUCCESS == code) {
+  if (TSDB_CODE_SUCCESS == code && NULL != pAgg->pAggFuncs) {
     code = rewriteExprsForSelect(pAgg->pAggFuncs, pSelect, SQL_CLAUSE_GROUP_BY);
   }
 
diff --git a/source/libs/planner/src/planOptimizer.c b/source/libs/planner/src/planOptimizer.c
index dee7bd49db..12d1d280c9 100644
--- a/source/libs/planner/src/planOptimizer.c
+++ b/source/libs/planner/src/planOptimizer.c
@@ -1986,7 +1986,8 @@ static bool lastRowScanOptMayBeOptimized(SLogicNode* pNode) {
 
   SNode* pFunc = NULL;
   FOREACH(pFunc, ((SAggLogicNode*)pNode)->pAggFuncs) {
-    if (FUNCTION_TYPE_LAST_ROW != ((SFunctionNode*)pFunc)->funcType) {
+    if (FUNCTION_TYPE_LAST_ROW != ((SFunctionNode*)pFunc)->funcType &&
+        FUNCTION_TYPE_SELECT_VALUE != ((SFunctionNode*)pFunc)->funcType) {
       return false;
     }
   }
diff --git a/source/libs/planner/src/planSpliter.c b/source/libs/planner/src/planSpliter.c
index d7eccf4b8e..987da0dd17 100644
--- a/source/libs/planner/src/planSpliter.c
+++ b/source/libs/planner/src/planSpliter.c
@@ -877,7 +877,7 @@ static int32_t stbSplSplitSortNode(SSplitContext* pCxt, SStableSplitInfo* pInfo)
   return code;
 }
 
-static int32_t stbSplSplitScanNode(SSplitContext* pCxt, SStableSplitInfo* pInfo) {
+static int32_t stbSplSplitScanNodeWithoutPartTags(SSplitContext* pCxt, SStableSplitInfo* pInfo) {
   int32_t code = splCreateExchangeNodeForSubplan(pCxt, pInfo->pSubplan, pInfo->pSplitNode, SUBPLAN_TYPE_MERGE);
   if (TSDB_CODE_SUCCESS == code) {
     code = nodesListMakeStrictAppend(&pInfo->pSubplan->pChildren,
@@ -887,6 +887,25 @@ static int32_t stbSplSplitScanNode(SSplitContext* pCxt, SStableSplitInfo* pInfo)
   return code;
 }
 
+static int32_t stbSplSplitScanNodeWithPartTags(SSplitContext* pCxt, SStableSplitInfo* pInfo) {
+  int32_t code = stbSplCreateMergeNode(pCxt, pInfo->pSubplan, pInfo->pSplitNode, NULL, pInfo->pSplitNode, true);
+  if (TSDB_CODE_SUCCESS == code) {
+    code = nodesListMakeStrictAppend(&pInfo->pSubplan->pChildren,
+                                     (SNode*)splCreateScanSubplan(pCxt, pInfo->pSplitNode, SPLIT_FLAG_STABLE_SPLIT));
+  }
+  pInfo->pSubplan->subplanType = SUBPLAN_TYPE_MERGE;
+  ++(pCxt->groupId);
+  return code;
+}
+
+static int32_t stbSplSplitScanNode(SSplitContext* pCxt, SStableSplitInfo* pInfo) {
+  SScanLogicNode* pScan = (SScanLogicNode*)pInfo->pSplitNode;
+  if (NULL != pScan->pGroupTags) {
+    return stbSplSplitScanNodeWithPartTags(pCxt, pInfo);
+  }
+  return stbSplSplitScanNodeWithoutPartTags(pCxt, pInfo);
+}
+
 static SNode* stbSplFindPrimaryKeyFromScan(SScanLogicNode* pScan) {
   SNode* pCol = NULL;
   FOREACH(pCol, pScan->pScanCols) {
diff --git a/source/libs/planner/test/planPartByTest.cpp b/source/libs/planner/test/planPartByTest.cpp
index 48a4c12577..f1dd9403dd 100644
--- a/source/libs/planner/test/planPartByTest.cpp
+++ b/source/libs/planner/test/planPartByTest.cpp
@@ -59,4 +59,6 @@ TEST_F(PlanPartitionByTest, withGroupBy) {
   useDb("root", "test");
 
   run("select count(*) from t1 partition by c1 group by c2");
+
+  run("SELECT TBNAME, c1 FROM st1 PARTITION BY TBNAME GROUP BY c1");
 }