feat: support partition by expression and aggregate function output together

source/libs/parser/src/parTranslater.c

@@ -1369,6 +1369,7 @@ static EDealRes rewriteExprToGroupKeyFunc(STranslateContext* pCxt, SNode** pNode
     *pNode = (SNode*)pFunc;
     pCxt->errCode = fmGetFuncInfo(pFunc, pCxt->msgBuf.buf, pCxt->msgBuf.len);
   }
+  pCxt->pCurrSelectStmt->hasAggFuncs = true;
 
   return (TSDB_CODE_SUCCESS == pCxt->errCode ? DEAL_RES_IGNORE_CHILD : DEAL_RES_ERROR);
 }
@@ -2506,8 +2507,24 @@ static SNode* createOrderByExpr(STranslateContext* pCxt) {
   return (SNode*)pOrder;
 }
 
-// from: select tail(expr, k, f) from t where_clause partition_by_clause order_by_clause ...
-// to: select expr from t where_clause order by _rowts desc limit k offset f
+/* case 1:
+ * in:  select tail(expr, k, f) from t where_clause
+ * out: select expr from t where_clause order by _rowts desc limit k offset f
+ *
+ * case 2:
+ * in:  select tail(expr, k, f) from t where_clause partition_by_clause
+ * out: select expr from t where_clause partition_by_clause sort by _rowts desc limit k offset f
+ *
+ * case 3:
+ * in:  select tail(expr, k, f) from t where_clause order_by_clause limit_clause
+ * out: select expr from (
+ *        select expr from t where_clause order by _rowts desc limit k offset f
+ *      ) order_by_clause limit_clause
+ *
+ * case 4:
+ * in:  select tail(expr, k, f) from t where_clause partition_by_clause limit_clause
+ * out:
+ */
 static int32_t rewriteTailStmt(STranslateContext* pCxt, SSelectStmt* pSelect) {
   if (!pSelect->hasTailFunc) {
     return TSDB_CODE_SUCCESS;

source/libs/planner/src/planOptimizer.c

@@ -1189,7 +1189,7 @@ static const SOptimizeRule optimizeRuleSet[] = {
   {.pName = "ConditionPushDown", .optimizeFunc = cpdOptimize},
   {.pName = "OrderByPrimaryKey", .optimizeFunc = opkOptimize},
   {.pName = "SmaIndex",          .optimizeFunc = smaOptimize},
-  // {.pName = "PartitionTags",     .optimizeFunc = partTagsOptimize},
+  {.pName = "PartitionTags",     .optimizeFunc = partTagsOptimize},
   {.pName = "EliminateProject",  .optimizeFunc = eliminateProjOptimize}
 };
 // clang-format on

source/libs/planner/test/planGroupByTest.cpp

@@ -53,14 +53,6 @@ TEST_F(PlanGroupByTest, aggFunc) {
   run("SELECT SUM(10), COUNT(c1) FROM t1 GROUP BY c2");
 }
 
-TEST_F(PlanGroupByTest, rewriteFunc) {
-  useDb("root", "test");
-
-  run("SELECT AVG(c1) FROM t1");
-
-  run("SELECT AVG(c1) FROM t1 GROUP BY c2");
-}
-
 TEST_F(PlanGroupByTest, selectFunc) {
   useDb("root", "test");
 
@@ -81,6 +73,8 @@ TEST_F(PlanGroupByTest, stable) {
 
   run("SELECT COUNT(*) FROM st1");
 
+  run("SELECT c1 FROM st1 GROUP BY c1");
+
   run("SELECT COUNT(*) FROM st1 GROUP BY c1");
 
   run("SELECT COUNT(*) FROM st1 PARTITION BY c2 GROUP BY c1");