From 7cbff7c2c2c80a6e1901092b386bb1aa85c671dc Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Mon, 25 May 2020 23:29:26 +0800
Subject: [PATCH] [td-225]fix bugs in empty super table query.

---
 src/client/src/tscAsync.c |  2 +-
 src/client/src/tscUtil.c  |  4 ++--
 src/query/src/qExecutor.c | 29 ++++++++++++++++++++---------
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index 6fba0efd97..d7224871da 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -165,7 +165,7 @@ static void tscProcessAsyncRetrieveImpl(void *param, TAOS_RES *tres, int numOfRo
   SSqlRes *pRes = &pSql->res;
 
   if ((pRes->qhandle == 0 || numOfRows != 0) && pCmd->command < TSDB_SQL_LOCAL) {
-    if (pRes->qhandle == 0) {
+    if (pRes->qhandle == 0 && numOfRows != 0) {
       tscError("qhandle is NULL");
     } else {
       pRes->code = numOfRows;
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index ec9908ae96..d66203ecbe 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -2010,7 +2010,7 @@ bool hasMoreVnodesToTry(SSqlObj* pSql) {
   STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
   assert(pRes->completed);
   
-  // for normal table, do not try any more if result are exhausted
+  // for normal table, no need to try any more if results are all retrieved from one vnode
   if (!UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo) || (pTableMetaInfo->vgroupList == NULL)) {
     return false;
   }
@@ -2036,7 +2036,7 @@ void tscTryQueryNextVnode(SSqlObj* pSql, __async_cb_func_t fp) {
   
   int32_t totalVgroups = pTableMetaInfo->vgroupList->numOfVgroups;
   while (++pTableMetaInfo->vgroupIndex < totalVgroups) {
-    tscTrace("%p current vnode:%d exhausted, try next:%d. total vnode:%d. current numOfRes:%d", pSql,
+    tscTrace("%p results from vgroup index:%d completed, try next:%d. total vgroups:%d. current numOfRes:%d", pSql,
              pTableMetaInfo->vgroupIndex - 1, pTableMetaInfo->vgroupIndex, totalVgroups, pRes->numOfClauseTotal);
 
     /*
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 47ad633e34..4b0ff36d36 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -4234,7 +4234,6 @@ static void setupQueryHandle(void* tsdb, SQInfo* pQInfo, bool isSTableQuery) {
   }
 }
 
-
 static SFillColInfo* taosCreateFillColInfo(SQuery* pQuery) {
   int32_t numOfCols = pQuery->numOfOutput;
   int32_t offset = 0;
@@ -5875,6 +5874,14 @@ static int32_t initQInfo(SQueryTableMsg *pQueryMsg, void *tsdb, int32_t vgId, SQ
     sem_post(&pQInfo->dataReady);
     return TSDB_CODE_SUCCESS;
   }
+  
+  if (pQInfo->groupInfo.numOfTables == 0) {
+    qTrace("QInfo:%p no table qualified for tag filter, abort query", pQInfo);
+    setQueryStatus(pQuery, QUERY_COMPLETED);
+  
+    sem_post(&pQInfo->dataReady);
+    return TSDB_CODE_SUCCESS;
+  }
 
   // filter the qualified
   if ((code = doInitQInfo(pQInfo, pTSBuf, tsdb, vgId, isSTable)) != TSDB_CODE_SUCCESS) {
@@ -6108,12 +6115,14 @@ int32_t qCreateQueryInfo(void *tsdb, int32_t vgId, SQueryTableMsg *pQueryMsg, qi
       // todo handle the error
       /*int32_t ret =*/tsdbQuerySTableByTagCond(tsdb, id->uid, tagCond, pQueryMsg->tagCondLen, pQueryMsg->tagNameRelType, tbnameCond, &groupInfo, pGroupColIndex,
                                           numOfGroupByCols);
-      if (groupInfo.numOfTables == 0) {  // no qualified tables no need to do query
-        code = TSDB_CODE_SUCCESS;
-        goto _over;
-      }
+//      if (groupInfo.numOfTables == 0) {  // no qualified tables no need to do query
+//        code = TSDB_CODE_SUCCESS;
+//        qTrace("qmsg:%p no results to produce by tag filters, return directly", pQueryMsg);
+
+//        goto _over;
+//      }
     } else {
-      groupInfo.numOfTables = taosArrayGetSize(pTableIdList);
+//      groupInfo.numOfTables = taosArrayGetSize(pTableIdList);
       SArray* pTableGroup = taosArrayInit(1, POINTER_BYTES);
 
       SArray* sa = taosArrayInit(groupInfo.numOfTables, sizeof(STableId));
@@ -6142,7 +6151,6 @@ _over:
   taosArrayDestroy(pTableIdList);
   
   // if failed to add ref for all meters in this query, abort current query
-  //  atomic_fetch_add_32(&vnodeSelectReqNum, 1);
   return code;
 }
 
@@ -6155,7 +6163,7 @@ void qTableQuery(qinfo_t qinfo) {
   SQInfo *pQInfo = (SQInfo *)qinfo;
 
   if (pQInfo == NULL || pQInfo->signature != pQInfo) {
-    qTrace("%p freed abort query", pQInfo);
+    qTrace("QInfo:%p has been freed, no need to execute", pQInfo);
     return;
   }
 
@@ -6268,7 +6276,10 @@ static void buildTagQueryResult(SQInfo* pQInfo) {
   SQuery *          pQuery = pRuntimeEnv->pQuery;
   
   size_t num = taosArrayGetSize(pQInfo->groupInfo.pGroupList);
-  assert(num == 1);   // only one group
+  assert(num == 0 || num == 1);
+  if (num == 0) {
+    return;
+  }
   
   SArray* pa = taosArrayGetP(pQInfo->groupInfo.pGroupList, 0);
   num = taosArrayGetSize(pa);
-- 
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