add the union support in sql parser. refactor some codes. fix bug in join...

add the union support in sql parser. refactor some codes. fix bug in join query caused by feature update #1032. [TBASE-1140]

src/client/inc/tscJoinProcess.h

@@ -121,7 +121,7 @@ STSBuf* tsBufCreate(bool autoDelete);
 STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete);
 STSBuf* tsBufCreateFromCompBlocks(const char* pData, int32_t numOfBlocks, int32_t len, int32_t tsOrder);
 
-void tsBufDestory(STSBuf* pTSBuf);
+void* tsBufDestory(STSBuf* pTSBuf);
 
 void tsBufAppend(STSBuf* pTSBuf, int32_t vnodeId, int64_t tag, const char* pData, int32_t len);
 int32_t tsBufMerge(STSBuf* pDestBuf, const STSBuf* pSrcBuf, int32_t vnodeIdx);

src/client/inc/tscUtil.h

@@ -128,7 +128,7 @@ void tscFieldInfoUpdateVisible(SFieldInfo* pFieldInfo, int32_t index, bool visib
 void tscFieldInfoCalOffset(SQueryInfo* pQueryInfo);
 void tscFieldInfoUpdateOffset(SQueryInfo* pQueryInfo);
 void tscFieldInfoCopy(SFieldInfo* src, SFieldInfo* dst, const int32_t* indexList, int32_t size);
-void tscFieldInfoCopyAll(SFieldInfo* src, SFieldInfo* dst);
+void tscFieldInfoCopyAll(SFieldInfo* dst, SFieldInfo* src);
 
 TAOS_FIELD* tscFieldInfoGetField(SQueryInfo* pQueryInfo, int32_t index);
 int16_t     tscFieldInfoGetOffset(SQueryInfo* pQueryInfo, int32_t index);
@@ -184,15 +184,17 @@ SMeterMetaInfo* tscGetMeterMetaInfo(SSqlCmd *pCmd, int32_t subClauseIndex, int32
 SMeterMetaInfo* tscGetMeterMetaInfoFromQueryInfo(SQueryInfo *pQueryInfo, int32_t tableIndex);
 
 SQueryInfo *tscGetQueryInfoDetail(SSqlCmd* pCmd, int32_t subClauseIndex);
+int32_t tscGetQueryInfoDetailSafely(SSqlCmd *pCmd, int32_t subClauseIndex, SQueryInfo** pQueryInfo);
 
 SMeterMetaInfo* tscGetMeterMetaInfoByUid(SQueryInfo* pQueryInfo, int32_t subClauseIndex, uint64_t uid, int32_t* index);
 void            tscClearMeterMetaInfo(SMeterMetaInfo* pMeterMetaInfo, bool removeFromCache);
 
-SMeterMetaInfo* tscAddMeterMetaInfo(SSqlCmd* pCmd, int32_t subClauseIndex, const char* name, SMeterMeta* pMeterMeta, SMetricMeta* pMetricMeta,
+SMeterMetaInfo* tscAddMeterMetaInfo(SQueryInfo* pQueryInfo, const char* name, SMeterMeta* pMeterMeta, SMetricMeta* pMetricMeta,
                                     int16_t numOfTags, int16_t* tags);
-SMeterMetaInfo* tscAddEmptyMeterMetaInfo(SSqlCmd* pCmd, int32_t subClauseIndex);
+SMeterMetaInfo* tscAddEmptyMeterMetaInfo(SQueryInfo *pQueryInfo);
 int32_t tscAddSubqueryInfo(SSqlCmd *pCmd);
 void tscFreeSubqueryInfo(SSqlCmd* pCmd);
+void tscClearSubqueryInfo(SSqlCmd* pCmd);
 
 void tscGetMetricMetaCacheKey(SSqlCmd* pCmd, int32_t subClauseIndex, char* keyStr, uint64_t uid);
 int  tscGetMetricMeta(SSqlObj* pSql);

src/client/inc/tsclient.h

@@ -400,7 +400,7 @@ typedef struct {
 } SIpStrList;
 
 // tscSql API
-int tsParseSql(SSqlObj *pSql, char *acct, char *db, bool multiVnodeInsertion);
+int tsParseSql(SSqlObj *pSql, bool multiVnodeInsertion);
 
 void  tscInitMsgs();
 extern int (*tscBuildMsg[TSDB_SQL_MAX])(SSqlObj *pSql, SSqlInfo *pInfo);

src/client/src/tscAsync.c

@@ -97,7 +97,7 @@ void taos_query_a(TAOS *taos, const char *sqlstr, void (*fp)(void *, TAOS_RES *,
   strtolower(pSql->sqlstr, sqlstr);
   tscTrace("%p Async SQL: %s, pObj:%p", pSql, pSql->sqlstr, pObj);
 
-  int32_t code = tsParseSql(pSql, pObj->acctId, pObj->db, true);
+  int32_t code = tsParseSql(pSql, true);
   if (code == TSDB_CODE_ACTION_IN_PROGRESS) return;
 
   if (code != TSDB_CODE_SUCCESS) {
@@ -523,7 +523,7 @@ void tscMeterMetaCallBack(void *param, TAOS_RES *res, int code) {
 
       if (code == TSDB_CODE_ACTION_IN_PROGRESS) return;
     } else {  // normal async query continues
-      code = tsParseSql(pSql, pObj->acctId, pObj->db, false);
+      code = tsParseSql(pSql, false);
       if (code == TSDB_CODE_ACTION_IN_PROGRESS) return;
     }
 

src/client/src/tscJoinProcess.c

@@ -277,7 +277,7 @@ int32_t tscLaunchSecondSubquery(SSqlObj* pSql) {
       return 0;
     }
 
-    tscFreeSqlCmdData(&pNew->cmd);
+    tscClearSubqueryInfo(&pNew->cmd);
 
     pSql->pSubs[j++] = pNew;
     SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pNew->cmd, 0);
@@ -298,7 +298,7 @@ int32_t tscLaunchSecondSubquery(SSqlObj* pSql) {
     tscTagCondCopy(&pQueryInfo->tagCond, &pSupporter->tagCond);
 
     tscSqlExprCopy(&pQueryInfo->exprsInfo, &pSupporter->exprsInfo, pSupporter->uid);
-    tscFieldInfoCopyAll(&pSupporter->fieldsInfo, &pQueryInfo->fieldsInfo);
+    tscFieldInfoCopyAll(&pQueryInfo->fieldsInfo, &pSupporter->fieldsInfo);
 
     // add the ts function for interval query if it is missing
     if (pSupporter->exprsInfo.pExprs[0].functionId != TSDB_FUNC_TS && pQueryInfo->nAggTimeInterval > 0) {
@@ -918,9 +918,9 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
   return pTSBuf;
 }
 
-void tsBufDestory(STSBuf* pTSBuf) {
+void* tsBufDestory(STSBuf* pTSBuf) {
   if (pTSBuf == NULL) {
-    return;
+    return NULL;
   }
 
   tfree(pTSBuf->assistBuf);
@@ -939,6 +939,7 @@ void tsBufDestory(STSBuf* pTSBuf) {
   }
 
   free(pTSBuf);
+  return NULL;
 }
 
 static STSVnodeBlockInfoEx* tsBufGetLastVnodeInfo(STSBuf* pTSBuf) {

src/client/src/tscParseInsert.c

@@ -944,10 +944,18 @@ int validateTableName(char *tblName, int len) {
 int doParseInsertSql(SSqlObj *pSql, char *str) {
   SSqlCmd *pCmd = &pSql->cmd;
   
-  int32_t code = TSDB_CODE_INVALID_SQL;
   int32_t totalNum = 0;
+  SQueryInfo* pQueryInfo = NULL;
+  SMeterMetaInfo* pMeterMetaInfo = NULL;
   
-  SMeterMetaInfo *pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pCmd, 0);
+  int32_t code = tscGetQueryInfoDetailSafely(pCmd, 0, &pQueryInfo);
+  
+  if (pQueryInfo->numOfTables == 0) {
+    pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pQueryInfo);
+  } else {
+    pMeterMetaInfo = tscGetMeterMetaInfoFromQueryInfo(pQueryInfo, 0);
+    assert(pQueryInfo->numOfTables == 1);
+  }
 
   if ((code = tscAllocPayload(pCmd, TSDB_PAYLOAD_SIZE)) != TSDB_CODE_SUCCESS) {
     return code;
@@ -1208,13 +1216,14 @@ _clean:
   return code;
 }
 
-int tsParseInsertSql(SSqlObj *pSql, char *sql, char *acct, char *db) {
+int tsParseInsertSql(SSqlObj *pSql) {
   if (!pSql->pTscObj->writeAuth) {
     return TSDB_CODE_NO_RIGHTS;
   }
 
   int32_t  index = 0;
   SSqlCmd *pCmd = &pSql->cmd;
+  char* sql = pSql->sqlstr;
   
   SSQLToken sToken = tStrGetToken(sql, &index, false, 0, NULL);
   
@@ -1234,12 +1243,9 @@ int tsParseInsertSql(SSqlObj *pSql, char *sql, char *acct, char *db) {
   return doParseInsertSql(pSql, sql + index);
 }
 
-int tsParseSql(SSqlObj *pSql, char *acct, char *db, bool multiVnodeInsertion) {
+int tsParseSql(SSqlObj *pSql, bool multiVnodeInsertion) {
   int32_t ret = TSDB_CODE_SUCCESS;
 
-  // must before clean the sqlcmd object
-//  tscRemoveMeterMetaInfo(&pSql->cmd, false);
-  
   if (NULL == pSql->asyncTblPos) {
     tscCleanSqlCmd(&pSql->cmd);
   } else {
@@ -1260,7 +1266,7 @@ int tsParseSql(SSqlObj *pSql, char *acct, char *db, bool multiVnodeInsertion) {
       pSql->fp = tscAsyncInsertMultiVnodesProxy;
     }
 
-    ret = tsParseInsertSql(pSql, pSql->sqlstr, acct, db);
+    ret = tsParseInsertSql(pSql);
   } else {
     ret = tscAllocPayload(&pSql->cmd, TSDB_DEFAULT_PAYLOAD_SIZE);
     if (TSDB_CODE_SUCCESS != ret) return ret;

src/client/src/tscPrepare.c

@@ -22,7 +22,7 @@
 #include "tstrbuild.h"
 
 
-int tsParseInsertSql(SSqlObj *pSql, char *sql, char *acct, char *db);
+int tsParseInsertSql(SSqlObj *pSql);
 int taos_query_imp(STscObj* pObj, SSqlObj* pSql);
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -385,12 +385,11 @@ static int insertStmtAddBatch(STscStmt* stmt) {
 }
 
 static int insertStmtPrepare(STscStmt* stmt) {
-  STscObj* taos = stmt->taos;
   SSqlObj *pSql = stmt->pSql;
   pSql->cmd.numOfParams = 0;
   pSql->cmd.batchSize = 0;
 
-  return tsParseInsertSql(pSql, pSql->sqlstr, taos->acctId, taos->db);
+  return tsParseInsertSql(pSql);
 }
 
 static int insertStmtReset(STscStmt* pStmt) {

src/client/src/tscSQLParser.c

@@ -199,14 +199,17 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
   }
 
   SSqlCmd* pCmd = &(pSql->cmd);
+  SQueryInfo* pQueryInfo = NULL;
 
   if (!pInfo->valid) {
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), pInfo->pzErrMsg);
   }
 
-  SMeterMetaInfo* pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pCmd, 0);
+  int32_t code = tscGetQueryInfoDetailSafely(pCmd, 0, &pQueryInfo);
+  
+  SMeterMetaInfo* pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pQueryInfo);
+  
   pCmd->command = pInfo->type;
-  int32_t code = 0;
 
   switch (pInfo->type) {
     case TSDB_SQL_DROP_TABLE:
@@ -226,7 +229,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       if (pInfo->type == TSDB_SQL_DROP_DB) {
         assert(pInfo->pDCLInfo->nTokens == 1);
 
-        int32_t code = setObjFullName(pMeterMetaInfo->name, getAccountId(pSql), pzName, NULL, NULL);
+        code = setObjFullName(pMeterMetaInfo->name, getAccountId(pSql), pzName, NULL, NULL);
         if (code != TSDB_CODE_SUCCESS) {
           return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
         }
@@ -500,7 +503,10 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       assert(pCmd->numOfClause == 1);
 
       for (int32_t i = pCmd->numOfClause; i < pInfo->subclauseInfo.numOfClause; ++i) {
-        tscAddEmptyMeterMetaInfo(pCmd, i);
+        SQueryInfo* pqi = NULL;
+        if ((code = tscGetQueryInfoDetailSafely(pCmd, i, &pqi)) != TSDB_CODE_SUCCESS) {
+          return code;
+        }
       }
 
       assert(pCmd->numOfClause == pInfo->subclauseInfo.numOfClause);
@@ -5384,9 +5390,9 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
       return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg0);
     }
 
-    SQueryInfo* pQueryInfo = pCmd->pQueryInfo[index];
+    SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, index);
     if (pQueryInfo->numOfTables <= i) {  // more than one table
-      tscAddEmptyMeterMetaInfo(pCmd, 0);
+      tscAddEmptyMeterMetaInfo(pQueryInfo);
     }
 
     SSQLToken t = {.type = TSDB_DATA_TYPE_BINARY, .n = pTableItem->nLen, .z = pTableItem->pz};

src/client/src/tscServer.c

@@ -666,23 +666,26 @@ int32_t tscLaunchJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSubquerySu
 
     // refactor as one method
     SQueryInfo* pNewQueryInfo = tscGetQueryInfoDetail(&pNew->cmd, 0);
+    assert(pNewQueryInfo != NULL);
+    
     tscColumnBaseInfoUpdateTableIndex(&pNewQueryInfo->colList, 0);
     tscColumnBaseInfoCopy(&pSupporter->colList, &pNewQueryInfo->colList, 0);
 
     tscSqlExprCopy(&pSupporter->exprsInfo, &pNewQueryInfo->exprsInfo, pSupporter->uid);
 
-    tscFieldInfoCopyAll(&pNewQueryInfo->fieldsInfo, &pSupporter->fieldsInfo);
+    tscFieldInfoCopyAll(&pSupporter->fieldsInfo, &pNewQueryInfo->fieldsInfo);
     tscTagCondCopy(&pSupporter->tagCond, &pNewQueryInfo->tagCond);
-    pSupporter->groupbyExpr = pNewQueryInfo->groupbyExpr;
 
     pNew->cmd.numOfCols = 0;
     pNewQueryInfo->nAggTimeInterval = 0;
     memset(&pNewQueryInfo->limit, 0, sizeof(SLimitVal));
+    
+    // backup the data and clear it in the sqlcmd object
+    pSupporter->groupbyExpr = pNewQueryInfo->groupbyExpr;
     memset(&pNewQueryInfo->groupbyExpr, 0, sizeof(SSqlGroupbyExpr));
 
     // set the ts,tags that involved in join, as the output column of intermediate result
-    pCmd->pDataBlocks = tscDestroyBlockArrayList(pNew->cmd.pDataBlocks);
-    tscFreeSubqueryInfo(&pNew->cmd);
+    tscClearSubqueryInfo(&pNew->cmd);
     
     SSchema      colSchema = {.type = TSDB_DATA_TYPE_BINARY, .bytes = 1};
     SColumnIndex index = {0, PRIMARYKEY_TIMESTAMP_COL_INDEX};
@@ -3458,7 +3461,7 @@ static int32_t tscDoGetMeterMeta(SSqlObj *pSql, char *meterId, int32_t index) {
   pNew->cmd.allocSize = 0;
 
   tscAddSubqueryInfo(&pNew->cmd);
-  pNew->cmd.numOfClause = 1;
+  assert(pNew->cmd.numOfClause == 1);
   
   SQueryInfo* pNewQueryInfo = tscGetQueryInfoDetail(&pNew->cmd, 0);
   pNewQueryInfo->defaultVal[0] = pQueryInfo->defaultVal[0];  // flag of create table if not exists
@@ -3469,7 +3472,7 @@ static int32_t tscDoGetMeterMeta(SSqlObj *pSql, char *meterId, int32_t index) {
     return TSDB_CODE_CLI_OUT_OF_MEMORY;
   }
 
-  SMeterMetaInfo *pMeterMetaInfo = tscAddEmptyMeterMetaInfo(&pNew->cmd, 0);
+  SMeterMetaInfo *pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pNewQueryInfo);
 
   strcpy(pMeterMetaInfo->name, meterId);
   memcpy(pNew->cmd.payload, pSql->cmd.payload, TSDB_DEFAULT_PAYLOAD_SIZE);
@@ -3639,10 +3642,10 @@ int tscGetMetricMeta(SSqlObj *pSql) {
   pNew->cmd.command = TSDB_SQL_METRIC;
 
   for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
-    SMeterMetaInfo *pMMInfo = tscGetMeterMetaInfo(&pSql->cmd, 0, i);
+    SMeterMetaInfo *pMMInfo = tscGetMeterMetaInfoFromQueryInfo(pQueryInfo, i);
   
     SMeterMeta *pMeterMeta = taosGetDataFromCache(tscCacheHandle, pMMInfo->name);
-    tscAddMeterMetaInfo(&pNew->cmd, 0, pMMInfo->name, pMeterMeta, NULL, pMMInfo->numOfTags, pMMInfo->tagColumnIndex);
+    tscAddMeterMetaInfo(pQueryInfo, pMMInfo->name, pMeterMeta, NULL, pMMInfo->numOfTags, pMMInfo->tagColumnIndex);
   }
 
   if ((code = tscAllocPayload(&pNew->cmd, TSDB_DEFAULT_PAYLOAD_SIZE)) != TSDB_CODE_SUCCESS) {

src/client/src/tscSql.c

@@ -212,7 +212,7 @@ int taos_query_imp(STscObj *pObj, SSqlObj *pSql) {
   
   tscTrace("%p SQL: %s pObj:%p", pSql, pSql->sqlstr, pObj);
 
-  pRes->code = (uint8_t)tsParseSql(pSql, pObj->acctId, pObj->db, false);
+  pRes->code = (uint8_t)tsParseSql(pSql, false);
 
   /*
    * set the qhandle to 0 before return in order to erase the qhandle value assigned in the previous successful query.
@@ -447,9 +447,9 @@ static bool tscHashRemainDataInSubqueryResultSet(SSqlObj *pSql) {
       SSqlRes *pRes1 = &pSql->pSubs[i]->res;
       SSqlCmd *pCmd1 = &pSql->pSubs[i]->cmd;
 
-      SMeterMetaInfo *pMetaInfo = tscGetMeterMetaInfo(pCmd1, 0, 0);
+      SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd1, 0);
+      SMeterMetaInfo *pMetaInfo = tscGetMeterMetaInfoFromQueryInfo(pQueryInfo, 0);
   
-      SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, 0);
       assert(pQueryInfo->numOfTables == 1);
 
       /*
@@ -972,7 +972,7 @@ int taos_validate_sql(TAOS *taos, const char *sql) {
     pSql->pTableHashList = NULL;
   }
 
-  pRes->code = (uint8_t)tsParseSql(pSql, pObj->acctId, pObj->db, false);
+  pRes->code = (uint8_t)tsParseSql(pSql, false);
   int code = pRes->code;
 
   tscTrace("%p Valid SQL result:%d, %s pObj:%p", pSql, pRes->code, taos_errstr(taos), pObj);
@@ -993,7 +993,13 @@ static int tscParseTblNameList(SSqlObj *pSql, const char *tblNameList, int32_t t
   int   code = TSDB_CODE_INVALID_METER_ID;
   char *str = (char *)tblNameList;
 
-  SMeterMetaInfo *pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pCmd, 0);
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  if (pQueryInfo == NULL) {
+    tscAddSubqueryInfo(pCmd);
+    pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  }
+  
+  SMeterMetaInfo *pMeterMetaInfo = tscAddEmptyMeterMetaInfo(pQueryInfo);
 
   if ((code = tscAllocPayload(pCmd, tblListLen + 16)) != TSDB_CODE_SUCCESS) {
     return code;

src/client/src/tscUtil.c

@@ -885,7 +885,7 @@ void tscFieldInfoCopy(SFieldInfo* src, SFieldInfo* dst, const int32_t* indexList
 
   if (size <= 0) {
     *dst = *src;
-    tscFieldInfoCopyAll(src, dst);
+    tscFieldInfoCopyAll(dst, src);
   } else {  // only copy the required column
     for (int32_t i = 0; i < size; ++i) {
       assert(indexList[i] >= 0 && indexList[i] <= src->numOfOutputCols);
@@ -894,7 +894,7 @@ void tscFieldInfoCopy(SFieldInfo* src, SFieldInfo* dst, const int32_t* indexList
   }
 }
 
-void tscFieldInfoCopyAll(SFieldInfo* src, SFieldInfo* dst) {
+void tscFieldInfoCopyAll(SFieldInfo* dst, SFieldInfo* src) {
   *dst = *src;
 
   dst->pFields = malloc(sizeof(TAOS_FIELD) * dst->numOfAlloc);
@@ -1565,18 +1565,18 @@ bool tscShouldFreeAsyncSqlObj(SSqlObj* pSql) {
 /**
  *
  * @param pCmd
- * @param unionSubClause denote the index of the union sub clause, usually are 0, if no union query exists.
+ * @param clauseIndex denote the index of the union sub clause, usually are 0, if no union query exists.
  * @param tableIndex  denote the table index for join query, where more than one table exists
  * @return
  */
-SMeterMetaInfo* tscGetMeterMetaInfo(SSqlCmd* pCmd, int32_t unionClauseIndex, int32_t tableIndex) {
+SMeterMetaInfo* tscGetMeterMetaInfo(SSqlCmd* pCmd, int32_t clauseIndex, int32_t tableIndex) {
   if (pCmd == NULL || pCmd->numOfClause == 0) {
     return NULL;
   }
 
-  assert(unionClauseIndex >= 0 && unionClauseIndex < pCmd->numOfClause);
+  assert(clauseIndex >= 0 && clauseIndex < pCmd->numOfClause);
 
-  SQueryInfo* pQueryInfo = pCmd->pQueryInfo[unionClauseIndex];
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, clauseIndex);
   return tscGetMeterMetaInfoFromQueryInfo(pQueryInfo, tableIndex);
 }
 
@@ -1601,6 +1601,23 @@ SQueryInfo* tscGetQueryInfoDetail(SSqlCmd* pCmd, int32_t subClauseIndex) {
   return pCmd->pQueryInfo[subClauseIndex];
 }
 
+int32_t tscGetQueryInfoDetailSafely(SSqlCmd *pCmd, int32_t subClauseIndex, SQueryInfo** pQueryInfo) {
+  int32_t ret = TSDB_CODE_SUCCESS;
+  assert(subClauseIndex >= 0 && subClauseIndex < TSDB_MAX_UNION_CLAUSE);
+  
+  *pQueryInfo = tscGetQueryInfoDetail(pCmd, subClauseIndex);
+  
+  while ((*pQueryInfo) == NULL) {
+    if ((ret = tscAddSubqueryInfo(pCmd)) != TSDB_CODE_SUCCESS) {
+      return ret;
+    }
+    
+    (*pQueryInfo) = tscGetQueryInfoDetail(pCmd, subClauseIndex);
+  }
+  
+  return TSDB_CODE_SUCCESS;
+}
+
 SMeterMetaInfo* tscGetMeterMetaInfoByUid(SQueryInfo* pQueryInfo, int32_t subClauseIndex, uint64_t uid, int32_t* index) {
   int32_t k = -1;
 
@@ -1636,7 +1653,7 @@ int32_t tscAddSubqueryInfo(SSqlCmd* pCmd) {
   return TSDB_CODE_SUCCESS;
 }
 
-static void doFreeSubqueryInfo(SQueryInfo* pQueryInfo, int64_t address) {
+static void doClearSubqueryInfo(SQueryInfo* pQueryInfo) {
   tscTagCondRelease(&pQueryInfo->tagCond);
   tscClearFieldInfo(&pQueryInfo->fieldsInfo);
   
@@ -1646,13 +1663,14 @@ static void doFreeSubqueryInfo(SQueryInfo* pQueryInfo, int64_t address) {
   tscColumnBaseInfoDestroy(&pQueryInfo->colList);
   memset(&pQueryInfo->colList, 0, sizeof(pQueryInfo->colList));
   
-  if (pQueryInfo->tsBuf != NULL) {
-    tsBufDestory(pQueryInfo->tsBuf);
-    pQueryInfo->tsBuf = NULL;
-  }
+  pQueryInfo->tsBuf = tsBufDestory(pQueryInfo->tsBuf);
+}
 
-  tscRemoveAllMeterMetaInfo(pQueryInfo, (const char*) address, false);
-  tfree(pQueryInfo);
+void tscClearSubqueryInfo(SSqlCmd* pCmd) {
+  for(int32_t i = 0; i < pCmd->numOfClause; ++i) {
+    SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, i);
+    doClearSubqueryInfo(pQueryInfo);
+  }
 }
 
 void tscFreeSubqueryInfo(SSqlCmd* pCmd) {
@@ -1661,24 +1679,26 @@ void tscFreeSubqueryInfo(SSqlCmd* pCmd) {
   }
 
   for (int32_t i = 0; i < pCmd->numOfClause; ++i) {
-    int64_t offset = offsetof(SSqlObj, cmd);
-    int64_t addr = (char*) pCmd - offset;
+    char *addr = (char *) pCmd - offsetof(SSqlObj, cmd);
+    
+    SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, i);
   
-    doFreeSubqueryInfo(tscGetQueryInfoDetail(pCmd, i), addr);
+    doClearSubqueryInfo(pQueryInfo);
+    tscRemoveAllMeterMetaInfo(pQueryInfo, (const char *) addr, false);
+    tfree(pQueryInfo);
   }
   
   pCmd->numOfClause = 0;
   tfree(pCmd->pQueryInfo);
 }
 
-SMeterMetaInfo* tscAddMeterMetaInfo(SSqlCmd* pCmd, int32_t subClauseIndex, const char* name, SMeterMeta* pMeterMeta,
+SMeterMetaInfo* tscAddMeterMetaInfo(SQueryInfo* pQueryInfo, const char* name, SMeterMeta* pMeterMeta,
                                     SMetricMeta* pMetricMeta, int16_t numOfTags, int16_t* tags) {
-  assert(subClauseIndex >= 0 && subClauseIndex < TSDB_MAX_UNION_CLAUSE);
-  while (pCmd->numOfClause <= subClauseIndex) {
-    tscAddSubqueryInfo(pCmd);
-  }
+//  while (pCmd->numOfClause <= subClauseIndex) {
+//    tscAddSubqueryInfo(pCmd);
+//  }
 
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+//  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
 
   void* pAlloc = realloc(pQueryInfo->pMeterInfo, (pQueryInfo->numOfTables + 1) * POINTER_BYTES);
   if (pAlloc == NULL) {
@@ -1708,8 +1728,8 @@ SMeterMetaInfo* tscAddMeterMetaInfo(SSqlCmd* pCmd, int32_t subClauseIndex, const
   return pMeterMetaInfo;
 }
 
-SMeterMetaInfo* tscAddEmptyMeterMetaInfo(SSqlCmd* pCmd, int32_t subClauseIndex) {
-  return tscAddMeterMetaInfo(pCmd, subClauseIndex, NULL, NULL, NULL, 0, NULL);
+SMeterMetaInfo* tscAddEmptyMeterMetaInfo(SQueryInfo* pQueryInfo) {
+  return tscAddMeterMetaInfo(pQueryInfo, NULL, NULL, NULL, 0, NULL);
 }
 
 void doRemoveMeterMetaInfo(SQueryInfo* pQueryInfo, int32_t index, bool removeFromCache) {
@@ -1858,11 +1878,11 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
     SMeterMeta*  pMeterMeta = taosGetDataFromCache(tscCacheHandle, name);
     SMetricMeta* pMetricMeta = taosGetDataFromCache(tscCacheHandle, key);
 
-    pFinalInfo = tscAddMeterMetaInfo(&pNew->cmd, 0, name, pMeterMeta, pMetricMeta, pMeterMetaInfo->numOfTags,
+    pFinalInfo = tscAddMeterMetaInfo(pNewQueryInfo, name, pMeterMeta, pMetricMeta, pMeterMetaInfo->numOfTags,
                                      pMeterMetaInfo->tagColumnIndex);
-  } else {
+  } else { // transfer the ownership of pMeterMeta/pMetricMeta to the newly create sql object.
     SMeterMetaInfo* pPrevInfo = tscGetMeterMetaInfo(&pPrevSql->cmd, 0, 0);
-    pFinalInfo = tscAddMeterMetaInfo(&pNew->cmd, 0, name, pPrevInfo->pMeterMeta, pPrevInfo->pMetricMeta,
+    pFinalInfo = tscAddMeterMetaInfo(pNewQueryInfo, name, pPrevInfo->pMeterMeta, pPrevInfo->pMetricMeta,
                                      pMeterMetaInfo->numOfTags, pMeterMetaInfo->tagColumnIndex);
 
     pPrevInfo->pMeterMeta = NULL;

src/system/detail/src/vnodeQueryImpl.c

@@ -2274,10 +2274,7 @@ static void teardownQueryRuntimeEnv(SQueryRuntimeEnv *pRuntimeEnv) {
     tfree(pRuntimeEnv->pInterpoBuf);
   }
 
-  if (pRuntimeEnv->pTSBuf != NULL) {
-    tsBufDestory(pRuntimeEnv->pTSBuf);
-    pRuntimeEnv->pTSBuf = NULL;
-  }
+  pRuntimeEnv->pTSBuf = tsBufDestory(pRuntimeEnv->pTSBuf);
 }
 
 // get maximum time interval in each file