Merge pull request #2033 from taosdata/feature/query

Feature/query

src/client/inc/tsclient.h

@@ -210,7 +210,7 @@ typedef struct SQueryInfo {
   int16_t          numOfTables;
   STableMetaInfo **pTableMetaInfo;
   struct STSBuf *  tsBuf;
-  int64_t *        defaultVal;   // default value for interpolation
+  int64_t *        fillVal;      // default value for interpolation
   char *           msg;          // pointer to the pCmd->payload to keep error message temporarily
   int64_t          clauseLimit;  // limit for current sub clause
 

src/client/src/tscFunctionImpl.c

@@ -390,7 +390,11 @@ static void function_finalizer(SQLFunctionCtx *pCtx) {
   
   if (pResInfo->hasResult != DATA_SET_FLAG) {
     tscTrace("no result generated, result is set to NULL");
-    setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+    if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+      setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+    } else {
+      setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+    }
   }
   
   doFinalizer(pCtx);
@@ -1864,12 +1868,22 @@ static void last_row_finalizer(SQLFunctionCtx *pCtx) {
   SResultInfo *pResInfo = GET_RES_INFO(pCtx);
   if (pCtx->currentStage == SECONDARY_STAGE_MERGE) {
     if (pResInfo->hasResult != DATA_SET_FLAG) {
-      setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+      if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+        setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+      } else {
+        setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+      }
+      
       return;
     }
   } else {
     if (pResInfo->hasResult != DATA_SET_FLAG) {
-      setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+      if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+        setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+      } else {
+        setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+      }
+      
       return;
     }
   }
@@ -2885,7 +2899,12 @@ static void leastsquares_finalizer(SQLFunctionCtx *pCtx) {
   SLeastsquareInfo *pInfo = pResInfo->interResultBuf;
   
   if (pInfo->num == 0) {
-    setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+    if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+      setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+    } else {
+      setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+    }
+    
     return;
   }
   
@@ -3139,7 +3158,7 @@ static void diff_function(SQLFunctionCtx *pCtx) {
           pOutput += 1;
           pTimestamp += 1;
         } else {
-          *pOutput = pData[i] - pCtx->param[1].i64Key;
+          *pOutput = pData[i] - pCtx->param[1].dKey;
           *pTimestamp = pCtx->ptsList[i];
           pOutput += 1;
           pTimestamp += 1;
@@ -3170,7 +3189,7 @@ static void diff_function(SQLFunctionCtx *pCtx) {
           pOutput += 1;
           pTimestamp += 1;
         } else {
-          *pOutput = pData[i] - pCtx->param[1].i64Key;
+          *pOutput = pData[i] - pCtx->param[1].dKey;
           *pTimestamp = pCtx->ptsList[i];
           
           pOutput += 1;
@@ -3862,7 +3881,11 @@ static void interp_function(SQLFunctionCtx *pCtx) {
       *(TSKEY *)pCtx->aOutputBuf = pInfoDetail->ts;
     } else {
       if (pInfoDetail->type == TSDB_FILL_NULL) {
-        setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+        if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+          setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+        } else {
+          setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+        }
       } else if (pInfoDetail->type == TSDB_FILL_SET_VALUE) {
         tVariantDump(&pCtx->param[1], pCtx->aOutputBuf, pCtx->inputType);
       } else if (pInfoDetail->type == TSDB_FILL_PREV) {
@@ -3914,7 +3937,11 @@ static void interp_function(SQLFunctionCtx *pCtx) {
           }
           
         } else {
-          setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
+          if (srcType == TSDB_DATA_TYPE_BINARY || srcType == TSDB_DATA_TYPE_NCHAR) {
+            setVardataNull(pCtx->aOutputBuf, pCtx->inputBytes);
+          } else {
+            setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
+          }
         }
       }
     }

src/client/src/tscParseInsert.c

@@ -312,8 +312,7 @@ int32_t tsParseOneColumnData(SSchema *pSchema, SSQLToken *pToken, char *payload,
     case TSDB_DATA_TYPE_BINARY:
       // binary data cannot be null-terminated char string, otherwise the last char of the string is lost
       if (pToken->type == TK_NULL) {
-        varDataSetLen(payload, sizeof(int8_t));
-        *(uint8_t*) varDataVal(payload) = TSDB_DATA_BINARY_NULL;
+        setVardataNull(payload, TSDB_DATA_TYPE_BINARY);
       } else { // too long values will return invalid sql, not be truncated automatically
         if (pToken->n + VARSTR_HEADER_SIZE > pSchema->bytes) { //todo refactor
           return tscInvalidSQLErrMsg(msg, "string data overflow", pToken->z);
@@ -326,8 +325,7 @@ int32_t tsParseOneColumnData(SSchema *pSchema, SSQLToken *pToken, char *payload,
 
     case TSDB_DATA_TYPE_NCHAR:
       if (pToken->type == TK_NULL) {
-        varDataSetLen(payload, sizeof(int32_t));
-        *(uint32_t*) varDataVal(payload) = TSDB_DATA_NCHAR_NULL;
+        setVardataNull(payload, TSDB_DATA_TYPE_NCHAR);
       } else {
         // if the converted output len is over than pColumnModel->bytes, return error: 'Argument list too long'
         size_t output = 0;

src/client/src/tscSQLParser.c

@@ -4015,9 +4015,9 @@ int32_t parseFillClause(SQueryInfo* pQueryInfo, SQuerySQL* pQuerySQL) {
   
   size_t size = tscSqlExprNumOfExprs(pQueryInfo);
   
-  if (pQueryInfo->defaultVal == NULL) {
-    pQueryInfo->defaultVal = calloc(size, sizeof(int64_t));
-    if (pQueryInfo->defaultVal == NULL) {
+  if (pQueryInfo->fillVal == NULL) {
+    pQueryInfo->fillVal = calloc(size, sizeof(int64_t));
+    if (pQueryInfo->fillVal == NULL) {
       return TSDB_CODE_CLI_OUT_OF_MEMORY;
     }
   }
@@ -4028,7 +4028,11 @@ int32_t parseFillClause(SQueryInfo* pQueryInfo, SQuerySQL* pQuerySQL) {
     pQueryInfo->fillType = TSDB_FILL_NULL;
     for (int32_t i = START_INTERPO_COL_IDX; i < size; ++i) {
       TAOS_FIELD* pFields = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, i);
-      setNull((char*)&pQueryInfo->defaultVal[i], pFields->type, pFields->bytes);
+      if (pFields->type == TSDB_DATA_TYPE_BINARY || pFields->type == TSDB_DATA_TYPE_NCHAR) {
+        setVardataNull((char*) &pQueryInfo->fillVal[i], pFields->type);
+      } else {
+        setNull((char*)&pQueryInfo->fillVal[i], pFields->type, pFields->bytes);
+      };
     }
   } else if (strncasecmp(pItem->pVar.pz, "prev", 4) == 0 && pItem->pVar.nLen == 4) {
     pQueryInfo->fillType = TSDB_FILL_PREV;
@@ -4061,11 +4065,11 @@ int32_t parseFillClause(SQueryInfo* pQueryInfo, SQuerySQL* pQuerySQL) {
       TAOS_FIELD* pFields = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, i);
 
       if (pFields->type == TSDB_DATA_TYPE_BINARY || pFields->type == TSDB_DATA_TYPE_NCHAR) {
-        setNull((char*)(&pQueryInfo->defaultVal[i]), pFields->type, pFields->bytes);
+        setVardataNull((char*) &pQueryInfo->fillVal[i], pFields->type);
         continue;
       }
 
-      int32_t ret = tVariantDump(&pFillToken->a[j].pVar, (char*)&pQueryInfo->defaultVal[i], pFields->type);
+      int32_t ret = tVariantDump(&pFillToken->a[j].pVar, (char*)&pQueryInfo->fillVal[i], pFields->type);
       if (ret != TSDB_CODE_SUCCESS) {
         return invalidSqlErrMsg(pQueryInfo->msg, msg);
       }
@@ -4079,9 +4083,9 @@ int32_t parseFillClause(SQueryInfo* pQueryInfo, SQuerySQL* pQuerySQL) {
         TAOS_FIELD* pFields = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, i);
 
         if (pFields->type == TSDB_DATA_TYPE_BINARY || pFields->type == TSDB_DATA_TYPE_NCHAR) {
-          setNull((char*)(&pQueryInfo->defaultVal[i]), pFields->type, pFields->bytes);
+          setVardataNull((char*) &pQueryInfo->fillVal[i], pFields->type);
         } else {
-          tVariantDump(&lastItem->pVar, (char*)&pQueryInfo->defaultVal[i], pFields->type);
+          tVariantDump(&lastItem->pVar, (char*)&pQueryInfo->fillVal[i], pFields->type);
         }
       }
     }

src/client/src/tscSecondaryMerge.c

@@ -145,7 +145,7 @@ static SFillColInfo* createFillColInfo(SQueryInfo* pQueryInfo) {
     pFillCol[i].flag       = pExpr->colInfo.flag;
     pFillCol[i].col.offset = offset;
     pFillCol[i].functionId = pExpr->functionId;
-    pFillCol[i].defaultVal.i = pQueryInfo->defaultVal[i];
+    pFillCol[i].fillVal.i  = pQueryInfo->fillVal[i];
     offset += pExpr->resBytes;
   }
   
@@ -946,8 +946,7 @@ static void doInterpolateResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, boo
   }
   
   while (1) {
-    int64_t newRows = -1;
-    taosGenerateDataBlock(pFillInfo, pResPages, &newRows, pLocalReducer->resColModel->capacity);
+    int64_t newRows = taosGenerateDataBlock(pFillInfo, pResPages, pLocalReducer->resColModel->capacity);
 
     if (pQueryInfo->limit.offset < newRows) {
       newRows -= pQueryInfo->limit.offset;

src/client/src/tscServer.c

@@ -781,8 +781,8 @@ int tscBuildQueryMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
   if (pQueryInfo->fillType != TSDB_FILL_NONE) {
     for (int32_t i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
-      *((int64_t *)pMsg) = htobe64(pQueryInfo->defaultVal[i]);
-      pMsg += sizeof(pQueryInfo->defaultVal[0]);
+      *((int64_t *)pMsg) = htobe64(pQueryInfo->fillVal[i]);
+      pMsg += sizeof(pQueryInfo->fillVal[0]);
     }
   }
   

src/client/src/tscStream.c

@@ -223,7 +223,7 @@ static void tscProcessStreamRetrieveResult(void *param, TAOS_RES *res, int numOf
           int16_t     offset = tscFieldInfoGetOffset(pQueryInfo, i);
           TAOS_FIELD *pField = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, i);
 
-          assignVal(pSql->res.data + offset, (char *)(&pQueryInfo->defaultVal[i]), pField->bytes, pField->type);
+          assignVal(pSql->res.data + offset, (char *)(&pQueryInfo->fillVal[i]), pField->bytes, pField->type);
           row[i] = pSql->res.data + offset;
         }
 

src/client/src/tscUtil.c

@@ -281,7 +281,7 @@ void tscClearInterpInfo(SQueryInfo* pQueryInfo) {
   }
 
   pQueryInfo->fillType = TSDB_FILL_NONE;
-  tfree(pQueryInfo->defaultVal);
+  tfree(pQueryInfo->fillVal);
 }
 
 int32_t tscCreateResPointerInfo(SSqlRes* pRes, SQueryInfo* pQueryInfo) {
@@ -1616,7 +1616,7 @@ static void freeQueryInfoImpl(SQueryInfo* pQueryInfo) {
   
   pQueryInfo->tsBuf = tsBufDestory(pQueryInfo->tsBuf);
 
-  tfree(pQueryInfo->defaultVal);
+  tfree(pQueryInfo->fillVal);
 }
 
 void tscClearSubqueryInfo(SSqlCmd* pCmd) {
@@ -1768,7 +1768,7 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
   pNewQueryInfo->order  = pQueryInfo->order;
   pNewQueryInfo->clauseLimit = pQueryInfo->clauseLimit;
   pNewQueryInfo->pTableMetaInfo = NULL;
-  pNewQueryInfo->defaultVal  = NULL;
+  pNewQueryInfo->fillVal  = NULL;
   pNewQueryInfo->numOfTables = 0;
   pNewQueryInfo->tsBuf = NULL;
   
@@ -1780,8 +1780,8 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
   tscTagCondCopy(&pNewQueryInfo->tagCond, &pQueryInfo->tagCond);
 
   if (pQueryInfo->fillType != TSDB_FILL_NONE) {
-    pNewQueryInfo->defaultVal = malloc(pQueryInfo->fieldsInfo.numOfOutput * sizeof(int64_t));
-    memcpy(pNewQueryInfo->defaultVal, pQueryInfo->defaultVal, pQueryInfo->fieldsInfo.numOfOutput * sizeof(int64_t));
+    pNewQueryInfo->fillVal = malloc(pQueryInfo->fieldsInfo.numOfOutput * sizeof(int64_t));
+    memcpy(pNewQueryInfo->fillVal, pQueryInfo->fillVal, pQueryInfo->fieldsInfo.numOfOutput * sizeof(int64_t));
   }
 
   if (tscAllocPayload(pnCmd, TSDB_DEFAULT_PAYLOAD_SIZE) != TSDB_CODE_SUCCESS) {

src/common/src/ttypes.c

@@ -381,6 +381,18 @@ bool isNull(const char *val, int32_t type) {
   };
 }
 
+void setVardataNull(char* val, int32_t type) {
+  if (type == TSDB_DATA_TYPE_BINARY) {
+    varDataSetLen(val, sizeof(int8_t));
+    *(uint8_t*) varDataVal(val) = TSDB_DATA_BINARY_NULL;
+  } else if (type == TSDB_DATA_TYPE_NCHAR) {
+    varDataSetLen(val, sizeof(int32_t));
+    *(uint32_t*) varDataVal(val) = TSDB_DATA_NCHAR_NULL;
+  } else {
+    assert(0);
+  }
+}
+
 void setNull(char *val, int32_t type, int32_t bytes) { setNullN(val, type, bytes, 1); }
 
 void setNullN(char *val, int32_t type, int32_t bytes, int32_t numOfElems) {
@@ -483,7 +495,7 @@ void assignVal(char *val, const char *src, int32_t len, int32_t type) {
       break;
     };
     case TSDB_DATA_TYPE_NCHAR: {
-      wcsncpy((wchar_t*)val, (wchar_t*)src, len / TSDB_NCHAR_SIZE);
+      varDataCopy(val, src);
       break;
     };
     default: {

src/inc/taosdef.h

@@ -157,6 +157,7 @@ extern tDataTypeDescriptor tDataTypeDesc[11];
 bool isValidDataType(int32_t type, int32_t length);
 bool isNull(const char *val, int32_t type);
 
+void setVardataNull(char* val, int32_t type);
 void setNull(char *val, int32_t type, int32_t bytes);
 void setNullN(char *val, int32_t type, int32_t bytes, int32_t numOfElems);
 

src/inc/taosmsg.h

@@ -443,7 +443,7 @@ typedef struct {
   int16_t     numOfOutput;  // final output columns numbers
   int16_t     tagNameRelType;   // relation of tag criteria and tbname criteria
   int16_t     fillType;      // interpolate type
-  uint64_t    defaultVal;       // default value array list
+  uint64_t    fillVal;       // default value array list
   int32_t     tsOffset;       // offset value in current msg body, NOTE: ts list is compressed
   int32_t     tsLen;          // total length of ts comp block
   int32_t     tsNumOfBlocks;  // ts comp block numbers

src/query/inc/qExecutor.h

@@ -138,7 +138,7 @@ typedef struct SQuery {
   SColumnInfo*      colList;
   SColumnInfo*      tagColList;
   int32_t           numOfFilterCols;
-  int64_t*          defaultVal;
+  int64_t*          fillVal;
   uint32_t          status;  // query status
   SResultRec        rec;
   int32_t           pos;

src/query/inc/qfill.h

@@ -28,7 +28,7 @@ typedef struct {
   STColumn col;             // column info
   int16_t  functionId;      // sql function id
   int16_t  flag;            // column flag: TAG COLUMN|NORMAL COLUMN
-  union {int64_t i; double d;} defaultVal;
+  union {int64_t i; double d;} fillVal;
 } SFillColInfo;
   
 typedef struct SFillInfo {
@@ -75,15 +75,13 @@ void taosFillCopyInputDataFromOneFilePage(SFillInfo* pFillInfo, tFilePage* pInpu
 
 TSKEY taosGetRevisedEndKey(TSKEY ekey, int32_t order, int64_t timeInterval, int8_t slidingTimeUnit, int8_t precision);
 
-int32_t taosGetNumOfResultWithFill(SFillInfo* pFillInfo, int32_t numOfRows, int64_t ekey, int32_t maxNumOfRows);
+int64_t taosGetNumOfResultWithFill(SFillInfo* pFillInfo, int32_t numOfRows, int64_t ekey, int32_t maxNumOfRows);
 
 int32_t taosNumOfRemainRows(SFillInfo *pFillInfo);
 
-int32_t taosDoInterpoResult(SFillInfo* pFillInfo, tFilePage** data, int32_t numOfRows, int32_t outputRows, char** srcData);
-  
 int taosDoLinearInterpolation(int32_t type, SPoint *point1, SPoint *point2, SPoint *point);
 
-void taosGenerateDataBlock(SFillInfo* pFillInfo, tFilePage** output, int64_t* outputRows, int32_t capacity);
+int64_t taosGenerateDataBlock(SFillInfo* pFillInfo, tFilePage** output, int32_t capacity);
 
 #ifdef __cplusplus
 }

src/query/src/qExecutor.c

@@ -376,11 +376,16 @@ bool isSelectivityWithTagsQuery(SQuery *pQuery) {
 
 bool isTSCompQuery(SQuery *pQuery) { return pQuery->pSelectExpr[0].base.functionId == TSDB_FUNC_TS_COMP; }
 
-static bool limitResults(SQuery *pQuery) {
+static bool limitResults(SQueryRuntimeEnv* pRuntimeEnv) {
+  SQInfo* pQInfo = GET_QINFO_ADDR(pRuntimeEnv);
+  SQuery* pQuery = pRuntimeEnv->pQuery;
+  
   if ((pQuery->limit.limit > 0) && (pQuery->rec.total + pQuery->rec.rows > pQuery->limit.limit)) {
     pQuery->rec.rows = pQuery->limit.limit - pQuery->rec.total;
-    assert(pQuery->rec.rows > 0);
-
+    
+    qTrace("QInfo:%p discard remain data due to result limitation, limit:%"PRId64", current return:%d, total:%"PRId64,
+        pQInfo, pQuery->limit.limit, pQuery->rec.rows, pQuery->rec.total + pQuery->rec.rows);
+    assert(pQuery->rec.rows >= 0);
     setQueryStatus(pQuery, QUERY_COMPLETED);
     return true;
   }
@@ -624,15 +629,17 @@ static int32_t getForwardStepsInBlock(int32_t numOfRows, __block_search_fn_t sea
 /**
  * NOTE: the query status only set for the first scan of master scan.
  */
-static void doCheckQueryCompleted(SQueryRuntimeEnv *pRuntimeEnv, TSKEY lastKey, SWindowResInfo *pWindowResInfo) {
+static int32_t doCheckQueryCompleted(SQueryRuntimeEnv *pRuntimeEnv, TSKEY lastKey, SWindowResInfo *pWindowResInfo) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
   if (pRuntimeEnv->scanFlag != MASTER_SCAN || (!isIntervalQuery(pQuery))) {
-    return;
+    return pWindowResInfo->size;
   }
 
   // no qualified results exist, abort check
+  int32_t numOfClosed = 0;
+  
   if (pWindowResInfo->size == 0) {
-    return;
+    return pWindowResInfo->size;
   }
 
   // query completed
@@ -646,10 +653,10 @@ static void doCheckQueryCompleted(SQueryRuntimeEnv *pRuntimeEnv, TSKEY lastKey,
     int32_t i = 0;
     int64_t skey = TSKEY_INITIAL_VAL;
 
-    // TODO opt performance: get the closed time window here
     for (i = 0; i < pWindowResInfo->size; ++i) {
       SWindowResult *pResult = &pWindowResInfo->pResult[i];
       if (pResult->status.closed) {
+        numOfClosed += 1;
         continue;
       }
 
@@ -672,16 +679,26 @@ static void doCheckQueryCompleted(SQueryRuntimeEnv *pRuntimeEnv, TSKEY lastKey,
 
     pWindowResInfo->prevSKey = pWindowResInfo->pResult[pWindowResInfo->curIndex].window.skey;
 
-    // the number of completed slots are larger than the threshold, dump to client immediately.
-    int32_t n = numOfClosedTimeWindow(pWindowResInfo);
-    if (n > pWindowResInfo->threshold) {
+    // the number of completed slots are larger than the threshold, return current generated results to client.
+    if (numOfClosed > pWindowResInfo->threshold) {
+      qTrace("QInfo:%p total result window:%d closed:%d, reached the output threshold %d, return",
+          GET_QINFO_ADDR(pRuntimeEnv), pWindowResInfo->size, numOfClosed, pQuery->rec.threshold);
+      
       setQueryStatus(pQuery, QUERY_RESBUF_FULL);
+    } else {
+      qTrace("QInfo:%p total result window:%d already closed:%d", GET_QINFO_ADDR(pRuntimeEnv), pWindowResInfo->size,
+             numOfClosed);
     }
-
-    qTrace("QInfo:%p total window:%d, closed:%d", GET_QINFO_ADDR(pRuntimeEnv), pWindowResInfo->size, n);
   }
-
+  
+  // output has reached the limitation, set query completed
+  if (pQuery->limit.limit > 0 && (pQuery->limit.limit + pQuery->limit.offset) <= numOfClosed &&
+      pRuntimeEnv->scanFlag == MASTER_SCAN) {
+    setQueryStatus(pQuery, QUERY_COMPLETED);
+  }
+  
   assert(pWindowResInfo->prevSKey != TSKEY_INITIAL_VAL);
+  return numOfClosed;
 }
 
 static int32_t getNumOfRowsInTimeWindow(SQuery *pQuery, SDataBlockInfo *pDataBlockInfo, TSKEY *pPrimaryColumn,
@@ -1309,28 +1326,27 @@ static int32_t tableApplyFunctionsOnBlock(SQueryRuntimeEnv *pRuntimeEnv, SDataBl
   TSKEY lastKey = QUERY_IS_ASC_QUERY(pQuery) ? pDataBlockInfo->window.ekey : pDataBlockInfo->window.skey;
   pTableQInfo->lastKey = lastKey + GET_FORWARD_DIRECTION_FACTOR(pQuery->order.order);
 
-  doCheckQueryCompleted(pRuntimeEnv, lastKey, pWindowResInfo);
 
   // interval query with limit applied
-  if (isIntervalQuery(pQuery) && pQuery->limit.limit > 0 &&
-      (pQuery->limit.limit + pQuery->limit.offset) <= numOfClosedTimeWindow(pWindowResInfo) &&
-      pRuntimeEnv->scanFlag == MASTER_SCAN) {
-    setQueryStatus(pQuery, QUERY_COMPLETED);
-  }
+  int32_t numOfRes = 0;
+  
+  if (isIntervalQuery(pQuery)) {
+    numOfRes = doCheckQueryCompleted(pRuntimeEnv, lastKey, pWindowResInfo);
+  } else {
+    numOfRes = getNumOfResult(pRuntimeEnv);
 
-  int32_t numOfRes = getNumOfResult(pRuntimeEnv);
+    // update the number of output result
+    if (numOfRes > 0 && pQuery->checkBuffer == 1) {
+      assert(numOfRes >= pQuery->rec.rows);
+      pQuery->rec.rows = numOfRes;
 
-  // update the number of output result
-  if (numOfRes > 0 && pQuery->checkBuffer == 1) {
-    assert(numOfRes >= pQuery->rec.rows);
-    pQuery->rec.rows = numOfRes;
+      if (numOfRes >= pQuery->rec.threshold) {
+        setQueryStatus(pQuery, QUERY_RESBUF_FULL);
+      }
 
-    if (numOfRes >= pQuery->rec.threshold) {
-      setQueryStatus(pQuery, QUERY_RESBUF_FULL);
-    }
-    
-    if ((pQuery->limit.limit >= 0) && numOfRes >= (pQuery->limit.limit + pQuery->limit.offset)) {
-      setQueryStatus(pQuery, QUERY_COMPLETED);
+      if ((pQuery->limit.limit >= 0) && (pQuery->limit.limit + pQuery->limit.offset) <= numOfRes) {
+        setQueryStatus(pQuery, QUERY_COMPLETED);
+      }
     }
   }
 
@@ -2026,10 +2042,10 @@ void pointInterpSupporterSetData(SQInfo *pQInfo, SPointInterpoSupporter *pPointI
 
         tVariantCreateFromBinary(&pCtx->param[3], (char *)&count, sizeof(count), TSDB_DATA_TYPE_INT);
 
-        if (isNull((char *)&pQuery->defaultVal[i], pCtx->inputType)) {
+        if (isNull((char *)&pQuery->fillVal[i], pCtx->inputType)) {
           pCtx->param[1].nType = TSDB_DATA_TYPE_NULL;
         } else {
-          tVariantCreateFromBinary(&pCtx->param[1], (char *)&pQuery->defaultVal[i], pCtx->inputBytes, pCtx->inputType);
+          tVariantCreateFromBinary(&pCtx->param[1], (char *)&pQuery->fillVal[i], pCtx->inputBytes, pCtx->inputType);
         }
 
         pInterpDetail->ts = pQuery->window.skey;
@@ -2471,8 +2487,8 @@ static int64_t doScanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
     SArray *pDataBlock = loadDataBlockOnDemand(pRuntimeEnv, pQueryHandle, &blockInfo, &pStatis);
     int32_t numOfRes = tableApplyFunctionsOnBlock(pRuntimeEnv, &blockInfo, pStatis, binarySearchForKey, pDataBlock);
 
-    qTrace("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", rows:%d, numOfRes:%d", GET_QINFO_ADDR(pRuntimeEnv),
-           blockInfo.window.skey, blockInfo.window.ekey, blockInfo.rows, numOfRes);
+    qTrace("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", numOfRows:%d, numOfRes:%d, lastKey:%"PRId64, GET_QINFO_ADDR(pRuntimeEnv),
+           blockInfo.window.skey, blockInfo.window.ekey, blockInfo.rows, numOfRes, pQuery->current->lastKey);
 
     // while the output buffer is full or limit/offset is applied, query may be paused here
     if (Q_STATUS_EQUAL(pQuery->status, QUERY_RESBUF_FULL | QUERY_COMPLETED)) {
@@ -3374,7 +3390,9 @@ static void clearEnvAfterReverseScan(SQueryRuntimeEnv *pRuntimeEnv, SQueryStatus
   // during reverse scan
   pTableQueryInfo->lastKey = pStatus->lastKey;
   pQuery->status = pStatus->status;
+  
   pTableQueryInfo->win = pStatus->w;
+  pQuery->window = pTableQueryInfo->win;
 }
 
 void scanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv, TSKEY start) {
@@ -3396,6 +3414,7 @@ void scanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv, TSKEY start) {
     if (pRuntimeEnv->scanFlag == MASTER_SCAN) {
       qstatus.status = pQuery->status;
       qstatus.curWindow.ekey = pTableQueryInfo->lastKey - step;
+      qstatus.lastKey = pTableQueryInfo->lastKey;
     }
 
     if (!needScanDataBlocksAgain(pRuntimeEnv)) {
@@ -3423,6 +3442,9 @@ void scanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv, TSKEY start) {
 
     setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
     pRuntimeEnv->scanFlag = REPEAT_SCAN;
+    
+    qTrace("QInfo:%p start to repeat scan data blocks due to query func required, qrange:%"PRId64"-%"PRId64, pQInfo,
+        cond.twindow.skey, cond.twindow.ekey);
 
     // check if query is killed or not
     if (isQueryKilled(pQInfo)) {
@@ -3707,7 +3729,7 @@ static int32_t doCopyToSData(SQInfo *pQInfo, SWindowResult *result, int32_t orde
   int32_t startIdx = 0;
   int32_t step = -1;
 
-  qTrace("QInfo:%p start to copy data from windowResInfo to query buf", GET_QINFO_ADDR(pQuery));
+  qTrace("QInfo:%p start to copy data from windowResInfo to query buf", pQInfo);
   int32_t totalSubset = getNumOfSubset(pQInfo);
 
   if (orderType == TSDB_ORDER_ASC) {
@@ -3836,7 +3858,7 @@ bool queryHasRemainResults(SQueryRuntimeEnv* pRuntimeEnv) {
   }
   
   /*
-   * There are no results returned to client now.
+   * While the code reaches here, there are no results returned to client now.
    * If query is not completed yet, the gaps between two results blocks need to be handled after next data block
    * is retrieved from TSDB.
    *
@@ -3890,18 +3912,24 @@ static void doCopyQueryResultToMsg(SQInfo *pQInfo, int32_t numOfRows, char *data
 }
 
 int32_t doFillGapsInResults(SQueryRuntimeEnv* pRuntimeEnv, tFilePage **pDst, int32_t numOfRows, int32_t *numOfInterpo) {
+  SQInfo* pQInfo = GET_QINFO_ADDR(pRuntimeEnv);
   SQuery *pQuery = pRuntimeEnv->pQuery;
+  SFillInfo* pFillInfo = pRuntimeEnv->pFillInfo;
+  
   while (1) {
-    taosGenerateDataBlock(pRuntimeEnv->pFillInfo, (tFilePage**) pQuery->sdata, &pQuery->rec.rows, pQuery->rec.capacity);
-    int32_t ret = pQuery->rec.rows;
+    int32_t ret = taosGenerateDataBlock(pFillInfo, (tFilePage**) pQuery->sdata, pQuery->rec.capacity);
     
     // todo apply limit output function
     /* reached the start position of according to offset value, return immediately */
     if (pQuery->limit.offset == 0) {
+      qTrace("QInfo:%p initial numOfRows:%d, generate filled result:%d rows", pQInfo, pFillInfo->numOfRows, ret);
       return ret;
     }
 
     if (pQuery->limit.offset < ret) {
+      qTrace("QInfo:%p initial numOfRows:%d, generate filled result:%d rows, offset:%d. Discard due to offset, remain:%d, new offset:%d",
+             pQInfo, pFillInfo->numOfRows, ret, pQuery->limit.offset, ret - pQuery->limit.offset, 0);
+      
       ret -= pQuery->limit.offset;
       // todo !!!!there exactly number of interpo is not valid.
       // todo refactor move to the beginning of buffer
@@ -3909,10 +3937,16 @@ int32_t doFillGapsInResults(SQueryRuntimeEnv* pRuntimeEnv, tFilePage **pDst, int
         memmove(pDst[i]->data, pDst[i]->data + pQuery->pSelectExpr[i].bytes * pQuery->limit.offset,
                 ret * pQuery->pSelectExpr[i].bytes);
       }
+      
       pQuery->limit.offset = 0;
       return ret;
     } else {
+      qTrace("QInfo:%p initial numOfRows:%d, generate filled result:%d rows, offset:%d. Discard due to offset, "
+             "remain:%d, new offset:%d", pQInfo, pFillInfo->numOfRows, ret, pQuery->limit.offset, 0,
+          pQuery->limit.offset - ret);
+      
       pQuery->limit.offset -= ret;
+      pQuery->rec.rows = 0;
       ret = 0;
     }
 
@@ -3920,8 +3954,6 @@ int32_t doFillGapsInResults(SQueryRuntimeEnv* pRuntimeEnv, tFilePage **pDst, int
       return ret;
     }
   }
-  
-  return 0;
 }
 
 void vnodePrintQueryStatistics(SQInfo *pQInfo) {
@@ -4002,8 +4034,8 @@ static void updateOffsetVal(SQueryRuntimeEnv *pRuntimeEnv, SDataBlockInfo *pBloc
 
   int32_t numOfRes = tableApplyFunctionsOnBlock(pRuntimeEnv, pBlockInfo, NULL, binarySearchForKey, pDataBlock);
 
-  qTrace("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", rows:%d, numOfRes:%d", GET_QINFO_ADDR(pRuntimeEnv),
-         pBlockInfo->window.skey, pBlockInfo->window.ekey, pBlockInfo->rows, numOfRes);
+  qTrace("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", numOfRows:%d, numOfRes:%d, lastKey:%"PRId64, GET_QINFO_ADDR(pRuntimeEnv),
+         pBlockInfo->window.skey, pBlockInfo->window.ekey, pBlockInfo->rows, numOfRes, pQuery->current->lastKey);
 }
 
 void skipBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
@@ -4120,8 +4152,9 @@ static bool skipTimeInterval(SQueryRuntimeEnv *pRuntimeEnv, TSKEY* start) {
           int32_t numOfRes = tableApplyFunctionsOnBlock(pRuntimeEnv, &blockInfo, NULL, binarySearchForKey, pDataBlock);
           pRuntimeEnv->windowResInfo.curIndex = index;  // restore the window index
           
-          qTrace("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", rows:%d, numOfRes:%d",
-                 GET_QINFO_ADDR(pRuntimeEnv), blockInfo.window.skey, blockInfo.window.ekey, blockInfo.rows, numOfRes);
+          qTrace("QInfo:%p check data block, brange:%" PRId64 "-%" PRId64 ", numOfRows:%d, numOfRes:%d, lastKey:%"PRId64,
+                 GET_QINFO_ADDR(pRuntimeEnv), blockInfo.window.skey, blockInfo.window.ekey, blockInfo.rows, numOfRes, pQuery->current->lastKey);
+          
           return true;
         } else { // do nothing
           *start = tw.skey;
@@ -4215,7 +4248,7 @@ static SFillColInfo* taosCreateFillColInfo(SQuery* pQuery) {
     pFillCol[i].col.offset = offset;
     pFillCol[i].flag       = TSDB_COL_NORMAL;    // always be ta normal column for table query
     pFillCol[i].functionId = pExprInfo->base.functionId;
-    pFillCol[i].defaultVal.i = pQuery->defaultVal[i];
+    pFillCol[i].fillVal.i = pQuery->fillVal[i];
     
     offset += pExprInfo->bytes;
   }
@@ -4591,7 +4624,7 @@ static void sequentialTableProcess(SQInfo *pQInfo) {
       skipResults(pRuntimeEnv);
 
       // the limitation of output result is reached, set the query completed
-      if (limitResults(pQuery)) {
+      if (limitResults(pRuntimeEnv)) {
         pQInfo->tableIndex = pQInfo->groupInfo.numOfTables;
         break;
       }
@@ -4846,7 +4879,7 @@ static void tableFixedOutputProcess(SQInfo *pQInfo, STableQueryInfo* pTableInfo)
   pQuery->rec.rows = getNumOfResult(pRuntimeEnv);
 
   skipResults(pRuntimeEnv);
-  limitResults(pQuery);
+  limitResults(pRuntimeEnv);
 }
 
 static void tableMultiOutputProcess(SQInfo *pQInfo, STableQueryInfo* pTableInfo) {
@@ -4894,7 +4927,7 @@ static void tableMultiOutputProcess(SQInfo *pQInfo, STableQueryInfo* pTableInfo)
     resetCtxOutputBuf(pRuntimeEnv);
   }
 
-  limitResults(pQuery);
+  limitResults(pRuntimeEnv);
   if (Q_STATUS_EQUAL(pQuery->status, QUERY_RESBUF_FULL)) {
     qTrace("QInfo:%p query paused due to output limitation, next qrange:%" PRId64 "-%" PRId64, pQInfo,
         pQuery->current->lastKey, pQuery->window.ekey);
@@ -4972,7 +5005,7 @@ static void tableIntervalProcess(SQInfo *pQInfo, STableQueryInfo* pTableInfo) {
 
     // the offset is handled at prepare stage if no interpolation involved
     if (pQuery->fillType == TSDB_FILL_NONE || pQuery->rec.rows == 0) {
-      limitResults(pQuery);
+      limitResults(pRuntimeEnv);
       break;
     } else {
       TSKEY ekey = taosGetRevisedEndKey(pQuery->window.ekey, pQuery->order.order, pQuery->slidingTime,
@@ -4980,11 +5013,10 @@ static void tableIntervalProcess(SQInfo *pQInfo, STableQueryInfo* pTableInfo) {
       taosFillSetStartInfo(pRuntimeEnv->pFillInfo, pQuery->rec.rows, ekey);
       taosFillCopyInputDataFromFilePage(pRuntimeEnv->pFillInfo, (tFilePage**) pQuery->sdata);
       numOfInterpo = 0;
+      
       pQuery->rec.rows = doFillGapsInResults(pRuntimeEnv, (tFilePage **)pQuery->sdata, pQuery->rec.rows, &numOfInterpo);
-
-      qTrace("QInfo: %p fill results completed, final:%d", pQInfo, pQuery->rec.rows);
       if (pQuery->rec.rows > 0 || Q_STATUS_EQUAL(pQuery->status, QUERY_COMPLETED)) {
-        limitResults(pQuery);
+        limitResults(pRuntimeEnv);
         break;
       }
 
@@ -5017,9 +5049,8 @@ static void tableQueryImpl(SQInfo *pQInfo) {
     int32_t remain = taosNumOfRemainRows(pRuntimeEnv->pFillInfo);
     pQuery->rec.rows = doFillGapsInResults(pRuntimeEnv, (tFilePage **)pQuery->sdata, remain, &numOfInterpo);
   
-    qTrace("QInfo: %p fill results completed, final:%d", pQInfo, pQuery->rec.rows);
     if (pQuery->rec.rows > 0) {
-      limitResults(pQuery);
+      limitResults(pRuntimeEnv);
     }
     
     qTrace("QInfo:%p current:%d returned, total:%d", pQInfo, pQuery->rec.rows, pQuery->rec.total);
@@ -5351,7 +5382,7 @@ static int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SArray **pTableIdList,
 
   pQueryMsg->fillType = htons(pQueryMsg->fillType);
   if (pQueryMsg->fillType != TSDB_FILL_NONE) {
-    pQueryMsg->defaultVal = (uint64_t)(pMsg);
+    pQueryMsg->fillVal = (uint64_t)(pMsg);
 
     int64_t *v = (int64_t *)pMsg;
     for (int32_t i = 0; i < pQueryMsg->numOfOutput; ++i) {
@@ -5722,13 +5753,13 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SArray* pTableIdList,
   }
 
   if (pQuery->fillType != TSDB_FILL_NONE) {
-    pQuery->defaultVal = malloc(sizeof(int64_t) * pQuery->numOfOutput);
-    if (pQuery->defaultVal == NULL) {
+    pQuery->fillVal = malloc(sizeof(int64_t) * pQuery->numOfOutput);
+    if (pQuery->fillVal == NULL) {
       goto _cleanup;
     }
 
     // the first column is the timestamp
-    memcpy(pQuery->defaultVal, (char *)pQueryMsg->defaultVal, pQuery->numOfOutput * sizeof(int64_t));
+    memcpy(pQuery->fillVal, (char *)pQueryMsg->fillVal, pQuery->numOfOutput * sizeof(int64_t));
   }
 
   // to make sure third party won't overwrite this structure
@@ -5785,7 +5816,7 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SArray* pTableIdList,
   return pQInfo;
 
 _cleanup:
-  tfree(pQuery->defaultVal);
+  tfree(pQuery->fillVal);
 
   if (pQuery->sdata != NULL) {
     for (int16_t col = 0; col < pQuery->numOfOutput; ++col) {
@@ -5893,8 +5924,8 @@ static void freeQInfo(SQInfo *pQInfo) {
     tfree(pQuery->pSelectExpr);
   }
 
-  if (pQuery->defaultVal != NULL) {
-    tfree(pQuery->defaultVal);
+  if (pQuery->fillVal != NULL) {
+    tfree(pQuery->fillVal);
   }
 
   // todo refactor, extract method to destroytableDataInfo
@@ -5997,8 +6028,13 @@ static int32_t doDumpQueryResult(SQInfo *pQInfo, char *data) {
   }
 
   pQuery->rec.total += pQuery->rec.rows;
-  qTrace("QInfo:%p current:%d, total:%d", pQInfo, pQuery->rec.rows, pQuery->rec.total);
+  qTrace("QInfo:%p current numOfRes rows:%d, total:%d", pQInfo, pQuery->rec.rows, pQuery->rec.total);
 
+  if (pQuery->limit.limit > 0 && pQuery->limit.limit == pQuery->rec.total) {
+    qTrace("QInfo:%p results limitation reached, limitation:%"PRId64, pQInfo, pQuery->limit.limit);
+    setQueryStatus(pQuery, QUERY_OVER);
+  }
+  
   return TSDB_CODE_SUCCESS;
 
   // todo if interpolation exists, the result may be dump to client by several rounds

src/query/src/qfill.c

@@ -34,7 +34,7 @@ int64_t taosGetIntervalStartTimestamp(int64_t startTime, int64_t slidingTime, ch
      * 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 dynamically decide the start time of a day
+     * TODO dynamically decide the start time of a day, move to common module
      */
 
     // todo refactor to extract function that is available for Linux/Windows/Mac platform
@@ -116,10 +116,9 @@ void taosFillSetStartInfo(SFillInfo* pFillInfo, int32_t numOfRows, TSKEY endKey)
     return;
   }
 
-  pFillInfo->rowIdx = 0;
+  pFillInfo->rowIdx    = 0;
+  pFillInfo->endKey    = endKey;
   pFillInfo->numOfRows = numOfRows;
-  
-  pFillInfo->endKey = endKey;
 }
 
 void taosFillCopyInputDataFromFilePage(SFillInfo* pFillInfo, tFilePage** pInput) {
@@ -131,6 +130,8 @@ void taosFillCopyInputDataFromFilePage(SFillInfo* pFillInfo, tFilePage** pInput)
 
 void taosFillCopyInputDataFromOneFilePage(SFillInfo* pFillInfo, tFilePage* pInput) {
   assert(pFillInfo->numOfRows == pInput->num);
+  int32_t t = 0;
+  
   for(int32_t i = 0; i < pFillInfo->numOfCols; ++i) {
     SFillColInfo* pCol = &pFillInfo->pFillCol[i];
     
@@ -138,7 +139,7 @@ void taosFillCopyInputDataFromOneFilePage(SFillInfo* pFillInfo, tFilePage* pInpu
     memcpy(pFillInfo->pData[i], s, pInput->num * pCol->col.bytes);
     
     if (pCol->flag == TSDB_COL_TAG) {  // copy the tag value
-      memcpy(pFillInfo->pTags[i], pFillInfo->pData[i], pCol->col.bytes);
+      memcpy(pFillInfo->pTags[t++], pFillInfo->pData[i], pCol->col.bytes);
     }
   }
 }
@@ -170,7 +171,7 @@ static int32_t taosGetTotalNumOfFilledRes(SFillInfo* pFillInfo, const TSKEY* tsA
   }
 }
 
-int32_t taosGetNumOfResultWithFill(SFillInfo* pFillInfo, int32_t numOfRows, int64_t ekey, int32_t maxNumOfRows) {
+int64_t taosGetNumOfResultWithFill(SFillInfo* pFillInfo, int32_t numOfRows, int64_t ekey, int32_t maxNumOfRows) {
   int32_t numOfRes = taosGetTotalNumOfFilledRes(pFillInfo, (int64_t*) pFillInfo->pData[0], numOfRows,
                                                 pFillInfo->slidingTime, ekey);
   return (numOfRes > maxNumOfRows) ? maxNumOfRows : numOfRes;
@@ -193,7 +194,7 @@ static double linearInterpolationImpl(double v1, double v2, double k1, double k2
 int taosDoLinearInterpolation(int32_t type, SPoint* point1, SPoint* point2, SPoint* point) {
   switch (type) {
     case TSDB_DATA_TYPE_INT: {
-      *(int32_t*)point->val = linearInterpolationImpl(*(int32_t*)point1->val, *(int32_t*)point2->val, point1->key,
+      *(int32_t*)point->val = (int32_t) linearInterpolationImpl(*(int32_t*)point1->val, *(int32_t*)point2->val, point1->key,
                                                         point2->key, point->key);
       break;
     }
@@ -209,17 +210,17 @@ int taosDoLinearInterpolation(int32_t type, SPoint* point1, SPoint* point2, SPoi
     };
     case TSDB_DATA_TYPE_TIMESTAMP:
     case TSDB_DATA_TYPE_BIGINT: {
-      *(int64_t*)point->val = linearInterpolationImpl(*(int64_t*)point1->val, *(int64_t*)point2->val, point1->key,
+      *(int64_t*)point->val = (int64_t) linearInterpolationImpl(*(int64_t*)point1->val, *(int64_t*)point2->val, point1->key,
                                                         point2->key, point->key);
       break;
     };
     case TSDB_DATA_TYPE_SMALLINT: {
-      *(int16_t*)point->val = linearInterpolationImpl(*(int16_t*)point1->val, *(int16_t*)point2->val, point1->key,
+      *(int16_t*)point->val = (int16_t) linearInterpolationImpl(*(int16_t*)point1->val, *(int16_t*)point2->val, point1->key,
                                                         point2->key, point->key);
       break;
     };
     case TSDB_DATA_TYPE_TINYINT: {
-      *(int8_t*)point->val =
+      *(int8_t*) point->val = (int8_t)
           linearInterpolationImpl(*(int8_t*)point1->val, *(int8_t*)point2->val, point1->key, point2->key, point->key);
       break;
     };
@@ -243,8 +244,8 @@ static void setTagsValue(SFillInfo* pColInfo, tFilePage** data, char** pTags, in
 
 static void doInterpoResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t* num, char** srcData,
                                 int64_t ts, char** pTags, bool outOfBound) {
-  char** prevValues = &pFillInfo->prevValues;
-  char** nextValues = &pFillInfo->nextValues;
+  char* prevValues = pFillInfo->prevValues;
+  char* nextValues = pFillInfo->nextValues;
 
   SPoint point1, point2, point;
 
@@ -257,16 +258,21 @@ static void doInterpoResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t*
 
   // set the other values
   if (pFillInfo->fillType == TSDB_FILL_PREV) {
-    char* pInterpolationData = FILL_IS_ASC_FILL(pFillInfo) ? *prevValues : *nextValues;
-    if (pInterpolationData != NULL) {
+    char* p = FILL_IS_ASC_FILL(pFillInfo) ? prevValues : nextValues;
+    
+    if (p != NULL) {
       for (int32_t i = 1; i < numOfValCols; ++i) {
         SFillColInfo* pCol = &pFillInfo->pFillCol[i];
         
         char* val1 = elePtrAt(data[i]->data, pCol->col.bytes, *num);
-        if (isNull(pInterpolationData + pCol->col.offset, pCol->col.type)) {
-          setNull(val1, pCol->col.type, pCol->col.bytes);
+        if (isNull(p + pCol->col.offset, pCol->col.type)) {
+          if (pCol->col.type == TSDB_DATA_TYPE_BINARY || pCol->col.type == TSDB_DATA_TYPE_NCHAR) {
+            setVardataNull(val1, pCol->col.type);
+          } else {
+            setNull(val1, pCol->col.type, pCol->col.bytes);
+          }
         } else {
-          assignVal(val1, pInterpolationData + pCol->col.offset, pCol->col.bytes, pCol->col.type);
+          assignVal(val1, p + pCol->col.offset, pCol->col.bytes, pCol->col.type);
         }
       }
     } else { // no prev value yet, set the value for NULL
@@ -274,14 +280,18 @@ static void doInterpoResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t*
         SFillColInfo* pCol = &pFillInfo->pFillCol[i];
 
         char* val1 = elePtrAt(data[i]->data, pCol->col.bytes, *num);
-        setNull(val1, pCol->col.type, pCol->col.bytes);
+        if (pCol->col.type == TSDB_DATA_TYPE_BINARY||pCol->col.type == TSDB_DATA_TYPE_NCHAR) {
+          setVardataNull(val1, pCol->col.type);
+        } else {
+          setNull(val1, pCol->col.type, pCol->col.bytes);
+        }
       }
     }
 
     setTagsValue(pFillInfo, data, pTags, numOfValCols, *num);
   } else if (pFillInfo->fillType == TSDB_FILL_LINEAR) {
     // TODO : linear interpolation supports NULL value
-    if (*prevValues != NULL && !outOfBound) {
+    if (prevValues != NULL && !outOfBound) {
       for (int32_t i = 1; i < numOfValCols; ++i) {
         SFillColInfo* pCol = &pFillInfo->pFillCol[i];
         
@@ -289,14 +299,17 @@ static void doInterpoResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t*
         int16_t bytes = pCol->col.bytes;
         
         char *val1 = elePtrAt(data[i]->data, pCol->col.bytes, *num);
-        if (type == TSDB_DATA_TYPE_BINARY || type == TSDB_DATA_TYPE_NCHAR || type == TSDB_DATA_TYPE_BOOL) {
+        if (type == TSDB_DATA_TYPE_BINARY|| type == TSDB_DATA_TYPE_NCHAR) {
+          setVardataNull(val1, pCol->col.type);
+          continue;
+        } else if (type == TSDB_DATA_TYPE_BOOL) {
           setNull(val1, pCol->col.type, bytes);
           continue;
         }
 
-        point1 = (SPoint){.key = *(TSKEY*)(*prevValues), .val = *prevValues + pCol->col.offset};
+        point1 = (SPoint){.key = *(TSKEY*)(prevValues), .val = prevValues + pCol->col.offset};
         point2 = (SPoint){.key = ts, .val = srcData[i] + pFillInfo->rowIdx * bytes};
-        point = (SPoint){.key = pFillInfo->start, .val = val1};
+        point  = (SPoint){.key = pFillInfo->start, .val = val1};
         taosDoLinearInterpolation(type, &point1, &point2, &point);
       }
 
@@ -307,7 +320,12 @@ static void doInterpoResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t*
         SFillColInfo* pCol = &pFillInfo->pFillCol[i];
   
         char* val1 = elePtrAt(data[i]->data, pCol->col.bytes, *num);
-        setNull(val1, pCol->col.type, pCol->col.bytes);
+  
+        if (pCol->col.type == TSDB_DATA_TYPE_BINARY || pCol->col.type == TSDB_DATA_TYPE_NCHAR) {
+          setVardataNull(val1, pCol->col.type);
+        } else {
+          setNull(val1, pCol->col.type, pCol->col.bytes);
+        }
       }
 
       setTagsValue(pFillInfo, data, pTags, numOfValCols, *num);
@@ -318,7 +336,7 @@ static void doInterpoResultImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t*
       SFillColInfo* pCol = &pFillInfo->pFillCol[i];
       
       char* val1 = elePtrAt(data[i]->data, pCol->col.bytes, *num);
-      assignVal(val1, (char*)&pCol->defaultVal.i, pCol->col.bytes, pCol->col.type);
+      assignVal(val1, (char*)&pCol->fillVal.i, pCol->col.bytes, pCol->col.type);
     }
 
     setTagsValue(pFillInfo, data, pTags, numOfValCols, *num);
@@ -338,11 +356,16 @@ static void initBeforeAfterDataBuf(SFillInfo* pFillInfo, char** nextValues) {
   *nextValues = calloc(1, pFillInfo->rowSize);
   for (int i = 1; i < pFillInfo->numOfCols; i++) {
     SFillColInfo* pCol = &pFillInfo->pFillCol[i];
-    setNull(*nextValues + pCol->col.offset, pCol->col.type, pCol->col.bytes);
+  
+    if (pCol->col.type == TSDB_DATA_TYPE_BINARY||pCol->col.type == TSDB_DATA_TYPE_NCHAR) {
+      setVardataNull(*nextValues + pCol->col.offset, pCol->col.type);
+    } else {
+      setNull(*nextValues + pCol->col.offset, pCol->col.type, pCol->col.bytes);
+    }
   }
 }
 
-int32_t taosDoInterpoResult(SFillInfo* pFillInfo, tFilePage** data, int32_t numOfRows, int32_t outputRows, char** srcData) {
+int32_t generateDataBlockImpl(SFillInfo* pFillInfo, tFilePage** data, int32_t numOfRows, int32_t outputRows, char** srcData) {
   int32_t num = 0;
   pFillInfo->numOfCurrent = 0;
 
@@ -356,8 +379,8 @@ int32_t taosDoInterpoResult(SFillInfo* pFillInfo, tFilePage** data, int32_t numO
 
   if (numOfRows == 0) {
     /*
-     * we need to rebuild whole result set
-     * NOTE:we need to keep the last saved data, to generated the filled data
+     * These data are generated according to fill strategy, since the current timestamp is out of time window of
+     * real result set. Note that we need to keep the direct previous result rows, to generated the filled data.
      */
     while (num < outputRows) {
       doInterpoResultImpl(pFillInfo, data, &num, srcData, pFillInfo->start, pTags, true);
@@ -387,7 +410,7 @@ int32_t taosDoInterpoResult(SFillInfo* pFillInfo, tFilePage** data, int32_t numO
         
         while (((pFillInfo->start < ts && FILL_IS_ASC_FILL(pFillInfo)) ||
                 (pFillInfo->start > ts && !FILL_IS_ASC_FILL(pFillInfo))) && num < outputRows) {
-          doInterpoResultImpl(pFillInfo, data, &num, srcData, pFillInfo->start, pTags, false);
+          doInterpoResultImpl(pFillInfo, data, &num, srcData, ts, pTags, false);
         }
 
         /* output buffer is full, abort */
@@ -420,7 +443,7 @@ int32_t taosDoInterpoResult(SFillInfo* pFillInfo, tFilePage** data, int32_t numO
               assignVal(val1, src, pCol->col.bytes, pCol->col.type);
               memcpy(*prevValues + pCol->col.offset, src, pCol->col.bytes);
             } else {
-              assignVal(val1, (char*) &pCol->defaultVal.i, pCol->col.bytes, pCol->col.type);
+              assignVal(val1, (char*) &pCol->fillVal.i, pCol->col.bytes, pCol->col.type);
             }
           }
         }
@@ -450,21 +473,12 @@ int32_t taosDoInterpoResult(SFillInfo* pFillInfo, tFilePage** data, int32_t numO
   }
 }
 
-void taosGenerateDataBlock(SFillInfo* pFillInfo, tFilePage** output, int64_t* outputRows, int32_t capacity) {
+int64_t taosGenerateDataBlock(SFillInfo* pFillInfo, tFilePage** output, int32_t capacity) {
     int32_t remain = taosNumOfRemainRows(pFillInfo);  // todo use iterator?
-    
-//    TSKEY ekey = taosGetRevisedEndKey(pQuery->window.ekey, pQuery->order.order, pQuery->slidingTime,
-//                                      pQuery->slidingTimeUnit, pQuery->precision);
-//    if (QUERY_IS_ASC_QUERY(pQuery)) {
-//      assert(ekey >= pQuery->window.ekey);
-//    } else {
-//      assert(ekey <= pQuery->window.ekey);
-//    }
-    
-    int32_t rows = taosGetNumOfResultWithFill(pFillInfo, remain, pFillInfo->endKey, capacity);
+    int32_t rows   = taosGetNumOfResultWithFill(pFillInfo, remain, pFillInfo->endKey, capacity);
   
-    int32_t numOfRes = taosDoInterpoResult(pFillInfo, output, remain, rows, pFillInfo->pData);
-    *outputRows = rows;
-    
+    int32_t numOfRes = generateDataBlockImpl(pFillInfo, output, remain, rows, pFillInfo->pData);
     assert(numOfRes == rows);
+    
+    return numOfRes;
 }

src/query/src/tvariant.c

@@ -101,11 +101,12 @@ void tVariantCreateFromBinary(tVariant *pVar, const char *pz, size_t len, uint32
       break;
     }
     case TSDB_DATA_TYPE_NCHAR: { // here we get the nchar length from raw binary bits length
-      pVar->nLen = len / TSDB_NCHAR_SIZE;
-      pVar->wpz = calloc(1, (pVar->nLen + 1) * TSDB_NCHAR_SIZE);
+      int32_t lenInwchar = len / TSDB_NCHAR_SIZE;
+      pVar->wpz = calloc(1, (lenInwchar + 1) * TSDB_NCHAR_SIZE);
       
-      wcsncpy(pVar->wpz, (wchar_t *)pz, pVar->nLen);
-      pVar->wpz[pVar->nLen] = 0;
+      wcsncpy(pVar->wpz, (wchar_t *)pz, lenInwchar);
+      pVar->wpz[lenInwchar] = 0;
+      pVar->nLen = len;
       
       break;
     }

src/tsdb/src/tsdbRead.c

@@ -1539,14 +1539,21 @@ int32_t tsdbRetrieveDataBlockStatisInfo(TsdbQueryHandleT* pQueryHandle, SDataSta
   tsdbLoadCompData(&pHandle->rhelper, pBlockInfo->compBlock, NULL);
   
   size_t numOfCols = QH_GET_NUM_OF_COLS(pHandle);
-  memset(pHandle->statis, 0, sizeof(SDataStatis) * numOfCols);
+  for(int32_t i = 0; i < numOfCols; ++i) {
+    SDataStatis* st = &pHandle->statis[i];
+    int32_t colId = st->colId;
+    
+    memset(st, 0, sizeof(SDataStatis));
+    st->colId = colId;
+  }
+  
   tsdbGetDataStatis(&pHandle->rhelper, pHandle->statis, numOfCols);
   
   *pBlockStatis = pHandle->statis;
   
   //update the number of NULL data rows
   for(int32_t i = 0; i < numOfCols; ++i) {
-    if (pHandle->statis[i].numOfNull == -1) {
+    if (pHandle->statis[i].numOfNull == -1) { // set the column data are all NULL
       pHandle->statis[i].numOfNull = pBlockInfo->compBlock->numOfRows;
     }
   }

tests/script/general/parser/limit2_query.sim

@@ -36,6 +36,7 @@ if $data01 != 2 then
   return -1
 endi
 if $data02 != tb2 then
+  print expect tb2, actual: $data02
   return -1
 endi
 if $data03 != tb2 then