support the sliding query [tbase-266]

src/client/src/tscSQLParser.c

@@ -62,7 +62,7 @@ static int32_t addExprAndResultField(SQueryInfo* pQueryInfo, int32_t colIdx, tSQ
 static int32_t insertResultField(SQueryInfo* pQueryInfo, int32_t outputIndex, SColumnList* pIdList, int16_t bytes,
                                  int8_t type, char* fieldName);
 static int32_t changeFunctionID(int32_t optr, int16_t* functionId);
-static int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isMetric);
+static int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable);
 
 static bool validateIpAddress(const char* ip, size_t size);
 static bool hasUnsupportFunctionsForSTableQuery(SQueryInfo* pQueryInfo);
@@ -93,6 +93,8 @@ static int32_t setKillInfo(SSqlObj* pSql, struct SSqlInfo* pInfo);
 
 static bool validateOneTags(SSqlCmd* pCmd, TAOS_FIELD* pTagField);
 static bool hasTimestampForPointInterpQuery(SQueryInfo* pQueryInfo);
+static bool hasDefaultQueryTimeRange(SQueryInfo *pQueryInfo);
+
 static void updateTagColumnIndex(SQueryInfo* pQueryInfo, int32_t tableIndex);
 
 static int32_t parseLimitClause(SQueryInfo* pQueryInfo, int32_t index, SQuerySQL* pQuerySql, SSqlObj* pSql);
@@ -4432,8 +4434,6 @@ int32_t parseLimitClause(SQueryInfo* pQueryInfo, int32_t clauseIndex, SQuerySQL*
   const char* msg1 = "slimit/soffset only available for STable query";
   const char* msg2 = "function not supported on table";
   const char* msg3 = "slimit/soffset can not apply to projection query";
-  const char* msg4 = "projection on super table requires order by clause along with limitation";
-  const char* msg5 = "ordered projection result too large";
   
   // handle the limit offset value, validate the limit
   pQueryInfo->limit = pQuerySql->limit;
@@ -5542,28 +5542,6 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
     }
   }
 
-  // set sliding value
-  SSQLToken* pSliding = &pQuerySql->sliding;
-  if (pSliding->n != 0) {
-    if (!tscEmbedded && pCmd->inStream == 0) {  // sliding only allowed in stream
-      const char* msg = "not support sliding in query";
-      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg);
-    }
-
-    getTimestampInUsFromStr(pSliding->z, pSliding->n, &pQueryInfo->nSlidingTime);
-    if (pMeterMetaInfo->pMeterMeta->precision == TSDB_TIME_PRECISION_MILLI) {
-      pQueryInfo->nSlidingTime /= 1000;
-    }
-
-    if (pQueryInfo->nSlidingTime < tsMinSlidingTime) {
-      return invalidSqlErrMsg(pQueryInfo->msg, msg3);
-    }
-
-    if (pQueryInfo->nSlidingTime > pQueryInfo->nAggTimeInterval) {
-      return invalidSqlErrMsg(pQueryInfo->msg, msg4);
-    }
-  }
-
   // set order by info
   if (parseOrderbyClause(pQueryInfo, pQuerySql, tsGetSchema(pMeterMetaInfo->pMeterMeta)) != TSDB_CODE_SUCCESS) {
     return TSDB_CODE_INVALID_SQL;
@@ -5602,6 +5580,30 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
   if (!hasTimestampForPointInterpQuery(pQueryInfo)) {
     return invalidSqlErrMsg(pQueryInfo->msg, msg2);
   }
+  
+  // set sliding value, the query time range needs to be decide in the first place
+  SSQLToken* pSliding = &pQuerySql->sliding;
+  if (pSliding->n != 0) {
+    if (!tscEmbedded && pCmd->inStream == 0 && hasDefaultQueryTimeRange(pQueryInfo)) {  // sliding only allowed in stream
+      const char* msg = "time range expected for sliding window query";
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg);
+    }
+    
+    getTimestampInUsFromStr(pSliding->z, pSliding->n, &pQueryInfo->nSlidingTime);
+    if (pMeterMetaInfo->pMeterMeta->precision == TSDB_TIME_PRECISION_MILLI) {
+      pQueryInfo->nSlidingTime /= 1000;
+    }
+    
+    if (pQueryInfo->nSlidingTime < tsMinSlidingTime) {
+      return invalidSqlErrMsg(pQueryInfo->msg, msg3);
+    }
+    
+    if (pQueryInfo->nSlidingTime > pQueryInfo->nAggTimeInterval) {
+      return invalidSqlErrMsg(pQueryInfo->msg, msg4);
+    }
+  } else {
+    pQueryInfo->nSlidingTime = -1;
+  }
 
   // in case of join query, time range is required.
   if (QUERY_IS_JOIN_QUERY(pQueryInfo->type)) {
@@ -5651,3 +5653,8 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
 
   return TSDB_CODE_SUCCESS;  // Does not build query message here
 }
+
+bool hasDefaultQueryTimeRange(SQueryInfo *pQueryInfo) {
+  return (pQueryInfo->stime == 0 && pQueryInfo->etime == INT64_MAX) ||
+         (pQueryInfo->stime == INT64_MAX && pQueryInfo->etime == 0);
+}
\ No newline at end of file

src/system/detail/inc/vnode.h

@@ -260,6 +260,7 @@ typedef struct SQuery {
   TSKEY       skey;
   TSKEY       ekey;
   int64_t     nAggTimeInterval;
+  int64_t     slidingTime;       // sliding time for sliding window query
   char        intervalTimeUnit;  // interval data type, used for daytime revise
   int8_t      precision;
   int16_t     numOfOutputCols;

src/system/detail/inc/vnodeQueryImpl.h

@@ -64,7 +64,7 @@ typedef enum {
    * the next query.
    *
    * this status is only exist in group-by clause and
-   * diff/add/division/mulitply/ query.
+   * diff/add/division/multiply/ query.
    */
   QUERY_RESBUF_FULL = 0x2,
 
@@ -149,7 +149,6 @@ void vnodeScanAllData(SQueryRuntimeEnv* pRuntimeEnv);
 int32_t vnodeQueryResultInterpolate(SQInfo* pQInfo, tFilePage** pDst, tFilePage** pDataSrc, int32_t numOfRows,
                                     int32_t* numOfInterpo);
 void copyResToQueryResultBuf(SMeterQuerySupportObj* pSupporter, SQuery* pQuery);
-void moveDescOrderResultsToFront(SQueryRuntimeEnv* pRuntimeEnv);
 
 void doSkipResults(SQueryRuntimeEnv* pRuntimeEnv);
 void doFinalizeResult(SQueryRuntimeEnv* pRuntimeEnv);
@@ -159,7 +158,7 @@ void forwardIntervalQueryRange(SMeterQuerySupportObj* pSupporter, SQueryRuntimeE
 void forwardQueryStartPosition(SQueryRuntimeEnv* pRuntimeEnv);
 
 bool normalizedFirstQueryRange(bool dataInDisk, bool dataInCache, SMeterQuerySupportObj* pSupporter,
-                               SPointInterpoSupporter* pPointInterpSupporter);
+                               SPointInterpoSupporter* pPointInterpSupporter, int64_t* key);
 
 void pointInterpSupporterInit(SQuery* pQuery, SPointInterpoSupporter* pInterpoSupport);
 void pointInterpSupporterDestroy(SPointInterpoSupporter* pPointInterpSupport);
@@ -278,6 +277,11 @@ void displayInterResult(SData** pdata, SQuery* pQuery, int32_t numOfRows);
 void vnodePrintQueryStatistics(SMeterQuerySupportObj* pSupporter);
 
 void clearGroupResultBuf(SOutputRes* pOneOutputRes, int32_t nOutputCols);
+void copyGroupResultBuf(SOutputRes* dst, const SOutputRes* src, int32_t nOutputCols);
+
+void resetResWindowInfo(SSlidingWindowResInfo* pWindowResInfo, int32_t numOfCols);
+void clearCompletedResWindows(SSlidingWindowResInfo* pWindowResInfo, int32_t numOfCols);
+int32_t numOfResFromResWindowInfo(SSlidingWindowResInfo* pWindowResInfo);
 
 #ifdef __cplusplus
 }

src/system/detail/inc/vnodeRead.h

@@ -112,7 +112,31 @@ typedef struct SQueryFilesInfo {
   char dbFilePathPrefix[PATH_MAX];
 } SQueryFilesInfo;
 
-typedef struct RuntimeEnvironment {
+typedef struct STimeWindow {
+  TSKEY skey;
+  TSKEY ekey;
+} STimeWindow;
+
+typedef struct SWindowStatus {
+  STimeWindow window;
+  bool closed;
+} SWindowStatus;
+
+typedef struct SSlidingWindowResInfo {
+  SOutputRes*         pResult;    // reference to SQuerySupporter->pResult
+  SWindowStatus*      pStatus;    // current query window closed or not?
+  void*               hashList;   // hash list for quick access
+  int16_t             type;       // data type for hash key
+  int32_t             capacity;   // max capacity
+  int32_t             curIndex;   // current start active index
+  int32_t             size;
+  
+  int64_t             startTime;  // start time of the first time window for sliding query
+  int64_t             prevSKey;   // previous (not completed) sliding window start key
+  int64_t             threshold;  // threshold for return completed results.
+} SSlidingWindowResInfo;
+
+typedef struct SQueryRuntimeEnv {
   SPositionInfo       startPos; /* the start position, used for secondary/third iteration */
   SPositionInfo       endPos;   /* the last access position in query, served as the start pos of reversed order query */
   SPositionInfo       nextPos;  /* start position of the next scan */
@@ -134,13 +158,16 @@ typedef struct RuntimeEnvironment {
   int16_t             scanFlag;  // denotes reversed scan of data or not
   SInterpolationInfo  interpoInfo;
   SData**             pInterpoBuf;
-  SOutputRes*         pResult;  // reference to SQuerySupporter->pResult
-  void*               hashList;
-  int32_t             usedIndex;  // assigned SOutputRes in list
+  
+  SSlidingWindowResInfo   swindowResInfo;
+  
   STSBuf*             pTSBuf;
   STSCursor           cur;
   SQueryCostSummary   summary;
   
+  TSKEY               intervalSKey;   // skey of the complete time window, not affected by the actual data distribution
+  TSKEY               intervalEKey;   // ekey of the complete time window
+  
   /*
    * Temporarily hold the in-memory cache block info during scan cache blocks
    * Here we do not use the cacheblock info from pMeterObj, simple because it may change anytime

src/system/detail/src/vnodeQueryProcess.c

@@ -535,7 +535,7 @@ static int64_t doCheckMetersInGroup(SQInfo *pQInfo, int32_t index, int32_t start
   SPointInterpoSupporter pointInterpSupporter = {0};
   pointInterpSupporterInit(pQuery, &pointInterpSupporter);
 
-  if (!normalizedFirstQueryRange(dataInDisk, dataInCache, pSupporter, &pointInterpSupporter)) {
+  if (!normalizedFirstQueryRange(dataInDisk, dataInCache, pSupporter, &pointInterpSupporter, NULL)) {
     pointInterpSupporterDestroy(&pointInterpSupporter);
     return 0;
   }
@@ -666,19 +666,10 @@ static void vnodeMultiMeterMultiOutputProcessor(SQInfo *pQInfo) {
     if (pSupporter->meterIdx >= pSids->numOfSids) {
       return;
     }
-
-    for (int32_t i = 0; i < pRuntimeEnv->usedIndex; ++i) {
-      SOutputRes *pOneRes = &pRuntimeEnv->pResult[i];
-      clearGroupResultBuf(pOneRes, pQuery->numOfOutputCols);
-    }
-
-    pRuntimeEnv->usedIndex = 0;
-    taosCleanUpHashTable(pRuntimeEnv->hashList);
-
-    int32_t primeHashSlot = 10039;
-    pRuntimeEnv->hashList = taosInitHashTable(primeHashSlot, taosIntHash_32, false);
-
-    while (pSupporter->meterIdx < pSupporter->numOfMeters) {
+  
+    resetResWindowInfo(&pRuntimeEnv->swindowResInfo, pQuery->numOfOutputCols);
+    
+      while (pSupporter->meterIdx < pSupporter->numOfMeters) {
       int32_t k = pSupporter->meterIdx;
 
       if (isQueryKilled(pQuery)) {
@@ -703,7 +694,7 @@ static void vnodeMultiMeterMultiOutputProcessor(SQInfo *pQInfo) {
 #endif
 
       SPointInterpoSupporter pointInterpSupporter = {0};
-      if (normalizedFirstQueryRange(dataInDisk, dataInCache, pSupporter, &pointInterpSupporter) == false) {
+      if (normalizedFirstQueryRange(dataInDisk, dataInCache, pSupporter, &pointInterpSupporter, NULL) == false) {
         pQuery->skey = pSupporter->rawSKey;
         pQuery->ekey = pSupporter->rawEKey;
 
@@ -778,8 +769,10 @@ static void vnodeMultiMeterMultiOutputProcessor(SQInfo *pQInfo) {
   }
 
   if (isGroupbyNormalCol(pQuery->pGroupbyExpr)) {
-    for (int32_t i = 0; i < pRuntimeEnv->usedIndex; ++i) {
-      SOutputRes *buf = &pRuntimeEnv->pResult[i];
+    SSlidingWindowResInfo* pWindowResInfo = &pRuntimeEnv->swindowResInfo;
+  
+    for (int32_t i = 0; i < pWindowResInfo->size; ++i) {
+      SOutputRes *buf = &pWindowResInfo->pResult[i];
       for (int32_t j = 0; j < pQuery->numOfOutputCols; ++j) {
         buf->numOfRows = MAX(buf->numOfRows, buf->resultInfo[j].numOfRes);
       }
@@ -787,14 +780,12 @@ static void vnodeMultiMeterMultiOutputProcessor(SQInfo *pQInfo) {
 
     pQInfo->pMeterQuerySupporter->subgroupIdx = 0;
     pQuery->pointsRead = 0;
-    copyFromGroupBuf(pQInfo, pRuntimeEnv->pResult);
+    copyFromGroupBuf(pQInfo, pWindowResInfo->pResult);
   }
 
   pQInfo->pointsRead += pQuery->pointsRead;
   pQuery->pointsOffset = pQuery->pointsToRead;
 
-  moveDescOrderResultsToFront(pRuntimeEnv);
-
   dTrace(
       "QInfo %p vid:%d, numOfMeters:%d, index:%d, numOfGroups:%d, %d points returned, totalRead:%d totalReturn:%d,"
       "next skey:%" PRId64 ", offset:%" PRId64,
@@ -982,12 +973,11 @@ static void vnodeSingleMeterFixedOutputProcessor(SQInfo *pQInfo) {
   if (isGroupbyNormalCol(pQuery->pGroupbyExpr)) {
     pQInfo->pMeterQuerySupporter->subgroupIdx = 0;
     pQuery->pointsRead = 0;
-    copyFromGroupBuf(pQInfo, pRuntimeEnv->pResult);
+    copyFromGroupBuf(pQInfo, pRuntimeEnv->swindowResInfo.pResult);
   }
 
   doSkipResults(pRuntimeEnv);
   doRevisedResultsByLimit(pQInfo);
-  moveDescOrderResultsToFront(pRuntimeEnv);
 
   pQInfo->pointsRead = pQuery->pointsRead;
 }
@@ -1034,8 +1024,6 @@ static void vnodeSingleMeterMultiOutputProcessor(SQInfo *pQInfo) {
   }
 
   doRevisedResultsByLimit(pQInfo);
-  moveDescOrderResultsToFront(pRuntimeEnv);
-
   pQInfo->pointsRead += pQuery->pointsRead;
 
   if (Q_STATUS_EQUAL(pQuery->over, QUERY_RESBUF_FULL)) {
@@ -1063,7 +1051,8 @@ static void vnodeSingleMeterIntervalMainLooper(SMeterQuerySupportObj *pSupporter
            (pQuery->skey >= pQuery->ekey && !QUERY_IS_ASC_QUERY(pQuery)));
 
     initCtxOutputBuf(pRuntimeEnv);
-
+    clearCompletedResWindows(&pRuntimeEnv->swindowResInfo, pQuery->numOfOutputCols);
+    
     vnodeScanAllData(pRuntimeEnv);
     if (isQueryKilled(pQuery)) {
       return;
@@ -1094,7 +1083,7 @@ static void vnodeSingleMeterIntervalMainLooper(SMeterQuerySupportObj *pSupporter
     }
 
     forwardIntervalQueryRange(pSupporter, pRuntimeEnv);
-    if (Q_STATUS_EQUAL(pQuery->over, QUERY_COMPLETED)) {
+    if (Q_STATUS_EQUAL(pQuery->over, QUERY_COMPLETED|QUERY_RESBUF_FULL)) {
       break;
     }
 
@@ -1133,17 +1122,8 @@ static void vnodeSingleMeterIntervalProcessor(SQInfo *pQInfo) {
       taosInterpoSetStartInfo(&pRuntimeEnv->interpoInfo, pQuery->pointsRead, pQuery->interpoType);
       SData **pInterpoBuf = pRuntimeEnv->pInterpoBuf;
 
-      if (QUERY_IS_ASC_QUERY(pQuery)) {
-        for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
-          memcpy(pInterpoBuf[i]->data, pQuery->sdata[i]->data, pQuery->pointsRead * pQuery->pSelectExpr[i].resBytes);
-        }
-      } else {
-        int32_t size = pMeterObj->pointsPerFileBlock;
-        for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
-          memcpy(pInterpoBuf[i]->data,
-                 pQuery->sdata[i]->data + (size - pQuery->pointsRead) * pQuery->pSelectExpr[i].resBytes,
-                 pQuery->pointsRead * pQuery->pSelectExpr[i].resBytes);
-        }
+      for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
+        memcpy(pInterpoBuf[i]->data, pQuery->sdata[i]->data, pQuery->pointsRead * pQuery->pSelectExpr[i].resBytes);
       }
 
       numOfInterpo = 0;
@@ -1160,12 +1140,16 @@ static void vnodeSingleMeterIntervalProcessor(SQInfo *pQInfo) {
       pQuery->pointsRead = 0;
     }
   }
+  
+  if (isGroupbyNormalCol(pQuery->pGroupbyExpr) || (pQuery->slidingTime > 0 && pQuery->nAggTimeInterval > 0)) {
+    pQInfo->pMeterQuerySupporter->subgroupIdx = 0;
+    pQuery->pointsRead = 0;
+    copyFromGroupBuf(pQInfo, pRuntimeEnv->swindowResInfo.pResult);
+  }
 
   pQInfo->pointsRead += pQuery->pointsRead;
   pQInfo->pointsInterpo += numOfInterpo;
 
-//  moveDescOrderResultsToFront(pRuntimeEnv);
-
   dTrace("%p vid:%d sid:%d id:%s, %d points returned %d points interpo, totalRead:%d totalInterpo:%d totalReturn:%d",
          pQInfo, pMeterObj->vnode, pMeterObj->sid, pMeterObj->meterId, pQuery->pointsRead, numOfInterpo,
          pQInfo->pointsRead - pQInfo->pointsInterpo, pQInfo->pointsInterpo, pQInfo->pointsReturned);
@@ -1209,7 +1193,6 @@ void vnodeSingleMeterQuery(SSchedMsg *pMsg) {
                                                      (tFilePage **)pRuntimeEnv->pInterpoBuf, remain, &numOfInterpo);
 
     doRevisedResultsByLimit(pQInfo);
-    moveDescOrderResultsToFront(pRuntimeEnv);
 
     pQInfo->pointsInterpo += numOfInterpo;
     pQInfo->pointsRead += pQuery->pointsRead;

src/system/detail/src/vnodeRead.c

@@ -267,6 +267,7 @@ static SQInfo *vnodeAllocateQInfoEx(SQueryMeterMsg *pQueryMsg, SSqlGroupbyExpr *
 
   pQuery->pGroupbyExpr = pGroupbyExpr;
   pQuery->nAggTimeInterval = pQueryMsg->nAggTimeInterval;
+  pQuery->slidingTime = pQueryMsg->slidingTime;
   pQuery->interpoType = pQueryMsg->interpoType;
   pQuery->intervalTimeUnit = pQueryMsg->intervalTimeUnit;
 
@@ -966,6 +967,8 @@ int32_t vnodeConvertQueryMeterMsg(SQueryMeterMsg *pQueryMsg) {
   pQueryMsg->queryType = htons(pQueryMsg->queryType);
 
   pQueryMsg->nAggTimeInterval = htobe64(pQueryMsg->nAggTimeInterval);
+  pQueryMsg->slidingTime = htobe64(pQueryMsg->slidingTime);
+  
   pQueryMsg->numOfTagsCols = htons(pQueryMsg->numOfTagsCols);
   pQueryMsg->numOfCols = htons(pQueryMsg->numOfCols);
   pQueryMsg->numOfOutputCols = htons(pQueryMsg->numOfOutputCols);

src/util/src/hash.c

@@ -423,7 +423,8 @@ void taosDeleteFromHashTable(HashObj *pObj, const char *key, uint32_t keyLen) {
     __wr_lock(&pObj->lock);
   }
 
-  SHashNode *pNode = doGetNodeFromHashTable(pObj, key, keyLen, NULL);
+  uint32_t val = 0;
+  SHashNode *pNode = doGetNodeFromHashTable(pObj, key, keyLen, &val);
   if (pNode == NULL) {
     if (pObj->multithreadSafe) {
       __unlock(&pObj->lock);
@@ -434,7 +435,12 @@ void taosDeleteFromHashTable(HashObj *pObj, const char *key, uint32_t keyLen) {
 
   SHashNode *pNext = pNode->next;
   if (pNode->prev != NULL) {
-    pNode->prev->next = pNext;
+    int32_t slot = HASH_INDEX(val, pObj->capacity);
+    if (pObj->hashList[slot]->next == pNode) {
+      pObj->hashList[slot]->next = pNext;
+    } else {
+      pNode->prev->next = pNext;
+    }
   }
   
   if (pNext != NULL) {

src/util/src/thashutil.c

@@ -93,6 +93,7 @@ uint32_t taosIntHash_64(const char *key, uint32_t UNUSED_PARAM(len)) {
 _hash_fn_t taosGetDefaultHashFunction(int32_t type) {
   _hash_fn_t fn = NULL;
   switch(type) {
+    case TSDB_DATA_TYPE_TIMESTAMP:
     case TSDB_DATA_TYPE_BIGINT: fn = taosIntHash_64;break;
     case TSDB_DATA_TYPE_BINARY: fn = MurmurHash3_32;break;
     case TSDB_DATA_TYPE_INT: fn = taosIntHash_32; break;

src/util/src/tinterpolation.c

@@ -37,7 +37,7 @@ int64_t taosGetIntervalStartTimestamp(int64_t startTime, int64_t timeRange, char
      * here we revised the start time of day according to the local time zone,
      * but in case of DST, the start time of one day need to be dynamically decided.
      *
-     * TODO dynmaically decide the start time of a day
+     * TODO dynamically decide the start time of a day
      */
 
 #if defined(WINDOWS) && _MSC_VER >= 1900
@@ -94,7 +94,7 @@ void taosInterpoSetStartInfo(SInterpolationInfo* pInterpoInfo, int32_t numOfRawD
     return;
   }
 
-  pInterpoInfo->rowIdx = INTERPOL_IS_ASC_INTERPOL(pInterpoInfo) ? 0 : numOfRawDataInRows - 1;
+  pInterpoInfo->rowIdx = 0;//INTERPOL_IS_ASC_INTERPOL(pInterpoInfo) ? 0 : numOfRawDataInRows - 1;
   pInterpoInfo->numOfRawDataInRows = numOfRawDataInRows;
 }
 
@@ -118,14 +118,14 @@ int32_t taosGetNumOfResWithoutLimit(SInterpolationInfo* pInterpoInfo, int64_t* p
   if (numOfAvailRawData > 0) {
     int32_t finalNumOfResult = 0;
 
-    if (pInterpoInfo->order == TSQL_SO_ASC) {
+//    if (pInterpoInfo->order == TSQL_SO_ASC) {
       // get last timestamp, calculate the result size
       int64_t lastKey = pPrimaryKeyArray[pInterpoInfo->numOfRawDataInRows - 1];
-      finalNumOfResult = (int32_t)((lastKey - pInterpoInfo->startTimestamp) / nInterval) + 1;
-    } else {  // todo error less than one!!!
-      TSKEY lastKey = pPrimaryKeyArray[0];
-      finalNumOfResult = (int32_t)((pInterpoInfo->startTimestamp - lastKey) / nInterval) + 1;
-    }
+      finalNumOfResult = (int32_t)(labs(lastKey - pInterpoInfo->startTimestamp) / nInterval) + 1;
+//    } else {  // todo error less than one!!!
+//      TSKEY lastKey = pPrimaryKeyArray[0];
+//      finalNumOfResult = (int32_t)((pInterpoInfo->startTimestamp - lastKey) / nInterval) + 1;
+//    }
 
     assert(finalNumOfResult >= numOfAvailRawData);
     return finalNumOfResult;
@@ -198,11 +198,11 @@ int taosDoLinearInterpolation(int32_t type, SPoint* point1, SPoint* point2, SPoi
 }
 
 static char* getPos(char* data, int32_t bytes, int32_t order, int32_t capacity, int32_t index) {
-  if (order == TSQL_SO_ASC) {
+//  if (order == TSQL_SO_ASC) {
     return data + index * bytes;
-  } else {
-    return data + (capacity - index - 1) * bytes;
-  }
+//  } else {
+//    return data + (capacity - index - 1) * bytes;
+//  }
 }
 
 static void setTagsValueInInterpolation(tFilePage** data, char** pTags, tColModel* pModel, int32_t order, int32_t start,
@@ -397,7 +397,7 @@ int32_t taosDoInterpoResult(SInterpolationInfo* pInterpoInfo, int16_t interpoTyp
       }
 
       pInterpoInfo->startTimestamp += (nInterval * step);
-      pInterpoInfo->rowIdx += step;
+      pInterpoInfo->rowIdx += 1;
       num += 1;
 
       if ((pInterpoInfo->rowIdx >= pInterpoInfo->numOfRawDataInRows && INTERPOL_IS_ASC_INTERPOL(pInterpoInfo)) ||