Merge pull request #4681 from taosdata/feature/query

Feature/query

src/client/src/tscAsync.c

@@ -388,10 +388,10 @@ void tscQueueAsyncRes(SSqlObj *pSql) {
     return;
   }
 
+  assert(pSql->res.code != TSDB_CODE_SUCCESS);
   tscError("%p add into queued async res, code:%s", pSql, tstrerror(pSql->res.code));
 
   SSqlRes *pRes = &pSql->res;
-
   if (pSql->fp == NULL || pSql->fetchFp == NULL){
     return;
   }

src/client/src/tscFunctionImpl.c

@@ -2597,14 +2597,23 @@ static void percentile_next_step(SQLFunctionCtx *pCtx) {
 }
 
 //////////////////////////////////////////////////////////////////////////////////
+static void buildHistogramInfo(SAPercentileInfo* pInfo) {
+  pInfo->pHisto = (SHistogramInfo*) ((char*) pInfo + sizeof(SAPercentileInfo));
+  pInfo->pHisto->elems = (SHistBin*) ((char*)pInfo->pHisto + sizeof(SHistogramInfo));
+}
+
 static SAPercentileInfo *getAPerctInfo(SQLFunctionCtx *pCtx) {
   SResultRowCellInfo *pResInfo = GET_RES_INFO(pCtx);
-  
+  SAPercentileInfo* pInfo = NULL;
+
   if (pCtx->stableQuery && pCtx->currentStage != SECONDARY_STAGE_MERGE) {
-    return (SAPercentileInfo*) pCtx->aOutputBuf;
+    pInfo = (SAPercentileInfo*) pCtx->aOutputBuf;
   } else {
-    return GET_ROWCELL_INTERBUF(pResInfo);
+    pInfo = GET_ROWCELL_INTERBUF(pResInfo);
   }
+
+  buildHistogramInfo(pInfo);
+  return pInfo;
 }
 
 static bool apercentile_function_setup(SQLFunctionCtx *pCtx) {
@@ -2616,6 +2625,7 @@ static bool apercentile_function_setup(SQLFunctionCtx *pCtx) {
   
   char *tmp = (char *)pInfo + sizeof(SAPercentileInfo);
   pInfo->pHisto = tHistogramCreateFrom(tmp, MAX_HISTOGRAM_BIN);
+  printf("%p, %p\n", pInfo->pHisto, pInfo->pHisto->elems);
   return true;
 }
 
@@ -2624,6 +2634,8 @@ static void apercentile_function(SQLFunctionCtx *pCtx) {
   
   SResultRowCellInfo *     pResInfo = GET_RES_INFO(pCtx);
   SAPercentileInfo *pInfo = getAPerctInfo(pCtx);
+
+  assert(pInfo->pHisto->elems != NULL);
   
   for (int32_t i = 0; i < pCtx->size; ++i) {
     char *data = GET_INPUT_CHAR_INDEX(pCtx, i);

src/common/src/tglobal.c

@@ -221,7 +221,7 @@ int32_t uDebugFlag = 131;
 int32_t debugFlag = 0;
 int32_t sDebugFlag = 135;
 int32_t wDebugFlag = 135;
-int32_t tsdbDebugFlag = 131;
+uint32_t tsdbDebugFlag = 131;
 int32_t cqDebugFlag = 131;
 
 int32_t (*monStartSystemFp)() = NULL;

grafanaplugin @ ec77d904

-Subproject commit 32e2c97a4cf7bedaa99f5d6dd8cb036e7f4470df
+Subproject commit ec77d9049a719dabfd1a7c1122a209e201861944

src/connector/nodejs/nodetaos/cinterface.js

@@ -349,11 +349,12 @@ CTaosInterface.prototype.useResult = function useResult(result) {
   return fields;
 }
 CTaosInterface.prototype.fetchBlock = function fetchBlock(result, fields) {
-  let pblock = ref.ref(ref.ref(ref.NULL)); // equal to our raw data
-  let num_of_rows = this.libtaos.taos_fetch_block(result, pblock)
-  if (num_of_rows == 0) {
+  //let pblock = ref.ref(ref.ref(ref.NULL)); // equal to our raw data
+  let pblock = this.libtaos.taos_fetch_row(result);
+  if (pblock == null) {
     return {block:null, num_of_rows:0};
   }
+
   var fieldL = this.libtaos.taos_fetch_lengths(result);
 
   let isMicro = (this.libtaos.taos_result_precision(result) == FieldTypes.C_TIMESTAMP_MICRO);
@@ -361,7 +362,6 @@ CTaosInterface.prototype.fetchBlock = function fetchBlock(result, fields) {
   var fieldlens = [];
   
   if (ref.isNull(fieldL) == false) {
-    
     for (let i = 0; i < fields.length; i ++) {
       let plen = ref.reinterpret(fieldL, 4, i*4);
       let len = plen.readInt32LE(0);

src/inc/ttype.h

@@ -28,7 +28,7 @@ extern "C" {
     default:                                         \
       (_v) = (_finalType)GET_INT32_VAL(_data);       \
       break;                                         \
-  };
+  }
 
 #ifdef __cplusplus
 }

src/query/inc/qExecutor.h

@@ -33,13 +33,6 @@ struct SColumnFilterElem;
 typedef bool (*__filter_func_t)(struct SColumnFilterElem* pFilter, char* val1, char* val2);
 typedef int32_t (*__block_search_fn_t)(char* data, int32_t num, int64_t key, int32_t order);
 
-typedef struct SGroupResInfo {
-  int32_t  groupId;
-  int32_t  numOfDataPages;
-  int32_t  pageId;
-  int32_t  rowId;
-} SGroupResInfo;
-
 typedef struct SResultRowPool {
   int32_t elemSize;
   int32_t blockSize;
@@ -72,6 +65,12 @@ typedef struct SResultRow {
   union {STimeWindow win; char* key;};  // start key of current time window
 } SResultRow;
 
+typedef struct SGroupResInfo {
+  int32_t rowId;
+  int32_t index;
+  SArray* pRows;      // SArray<SResultRow*>
+} SGroupResInfo;
+
 /**
  * If the number of generated results is greater than this value,
  * query query will be halt and return results to client immediate.
@@ -89,7 +88,6 @@ typedef struct SResultRowInfo {
   int32_t      size:24;    // number of result set
   int32_t      capacity;   // max capacity
   int32_t      curIndex;   // current start active index
-  int64_t      startTime;  // start time of the first time window for sliding query
   int64_t      prevSKey;   // previous (not completed) sliding window start key
 } SResultRowInfo;
 

src/query/inc/qHistogram.h

@@ -67,7 +67,7 @@ void tHistogramDestroy(SHistogramInfo** pHisto);
 
 void tHistogramPrint(SHistogramInfo* pHisto);
 
-int32_t vnodeHistobinarySearch(SHistBin* pEntry, int32_t len, double val);
+//int32_t histoBinarySearch(SHistBin* pEntry, int32_t len, double val);
 
 SHeapEntry* tHeapCreate(int32_t numOfEntries);
 void tHeapSort(SHeapEntry* pEntry, int32_t len);

src/query/inc/qUtil.h

@@ -77,7 +77,6 @@ void* destroyResultRowPool(SResultRowPool* p);
 int32_t getNumOfAllocatedResultRows(SResultRowPool* p);
 int32_t getNumOfUsedResultRows(SResultRowPool* p);
 
-uint64_t getResultInfoUId(SQueryRuntimeEnv* pRuntimeEnv);
 bool isPointInterpoQuery(SQuery *pQuery);
 
 

src/query/src/qHistogram.c

@@ -120,6 +120,7 @@
 //}
 
 static int32_t histogramCreateBin(SHistogramInfo* pHisto, int32_t index, double val);
+static int32_t histoBinarySearch(SHistBin* pEntry, int32_t len, double val);
 
 SHistogramInfo* tHistogramCreate(int32_t numOfEntries) {
   /* need one redundant slot */
@@ -158,8 +159,8 @@ int32_t tHistogramAdd(SHistogramInfo** pHisto, double val) {
   }
 
 #if defined(USE_ARRAYLIST)
-  int32_t idx = vnodeHistobinarySearch((*pHisto)->elems, (*pHisto)->numOfEntries, val);
-  assert(idx >= 0 && idx <= (*pHisto)->maxEntries);
+  int32_t idx = histoBinarySearch((*pHisto)->elems, (*pHisto)->numOfEntries, val);
+  assert(idx >= 0 && idx <= (*pHisto)->maxEntries && (*pHisto)->elems != NULL);
 
   if ((*pHisto)->elems[idx].val == val && idx >= 0) {
     (*pHisto)->elems[idx].num += 1;
@@ -356,7 +357,7 @@ int32_t tHistogramAdd(SHistogramInfo** pHisto, double val) {
   return 0;
 }
 
-int32_t vnodeHistobinarySearch(SHistBin* pEntry, int32_t len, double val) {
+int32_t histoBinarySearch(SHistBin* pEntry, int32_t len, double val) {
   int32_t end = len - 1;
   int32_t start = 0;
 
@@ -466,7 +467,7 @@ void tHistogramPrint(SHistogramInfo* pHisto) {
  */
 int64_t tHistogramSum(SHistogramInfo* pHisto, double v) {
 #if defined(USE_ARRAYLIST)
-  int32_t slotIdx = vnodeHistobinarySearch(pHisto->elems, pHisto->numOfEntries, v);
+  int32_t slotIdx = histoBinarySearch(pHisto->elems, pHisto->numOfEntries, v);
   if (pHisto->elems[slotIdx].val != v) {
     slotIdx -= 1;
 

src/query/src/qUtil.c

@@ -96,8 +96,6 @@ void resetResultRowInfo(SQueryRuntimeEnv *pRuntimeEnv, SResultRowInfo *pResultRo
   
   pResultRowInfo->curIndex = -1;
   pResultRowInfo->size = 0;
-  
-  pResultRowInfo->startTime = TSKEY_INITIAL_VAL;
   pResultRowInfo->prevSKey = TSKEY_INITIAL_VAL;
 }
 
@@ -110,7 +108,7 @@ void popFrontResultRow(SQueryRuntimeEnv *pRuntimeEnv, SResultRowInfo *pResultRow
   assert(num >= 0 && num <= numOfClosed);
 
   int16_t type = pResultRowInfo->type;
-  int64_t uid = getResultInfoUId(pRuntimeEnv);
+  int64_t uid  = 0;
 
   char    *key  = NULL;
   int16_t  bytes = -1;
@@ -181,11 +179,12 @@ void closeAllResultRows(SResultRowInfo *pResultRowInfo) {
   assert(pResultRowInfo->size >= 0 && pResultRowInfo->capacity >= pResultRowInfo->size);
   
   for (int32_t i = 0; i < pResultRowInfo->size; ++i) {
-    if (pResultRowInfo->pResult[i]->closed) {
+    SResultRow* pRow = pResultRowInfo->pResult[i];
+    if (pRow->closed) {
       continue;
     }
     
-    pResultRowInfo->pResult[i]->closed = true;
+    pRow->closed = true;
   }
 }
 
@@ -383,18 +382,4 @@ void* destroyResultRowPool(SResultRowPool* p) {
 
   tfree(p);
   return NULL;
-}
-
-uint64_t getResultInfoUId(SQueryRuntimeEnv* pRuntimeEnv) {
-  if (!pRuntimeEnv->stableQuery) {
-    return 0;  // for simple table query, the uid is always set to be 0;
-  }
-
-  SQuery* pQuery = pRuntimeEnv->pQuery;
-  if (pQuery->interval.interval == 0 || isPointInterpoQuery(pQuery) || pRuntimeEnv->groupbyNormalCol) {
-    return 0;
-  }
-
-  STableId* id = TSDB_TABLEID(pRuntimeEnv->pQuery->current->pTable);
-  return id->uid;
 }
\ No newline at end of file

src/tsdb/inc/tsdbMain.h

@@ -31,19 +31,19 @@
 extern "C" {
 #endif
 
-extern int tsdbDebugFlag;
+extern uint32_t tsdbDebugFlag;
 
-#define tsdbFatal(...) { if (tsdbDebugFlag & DEBUG_FATAL) { taosPrintLog("TDB FATAL ", 255, __VA_ARGS__); }}
-#define tsdbError(...) { if (tsdbDebugFlag & DEBUG_ERROR) { taosPrintLog("TDB ERROR ", 255, __VA_ARGS__); }}
-#define tsdbWarn(...)  { if (tsdbDebugFlag & DEBUG_WARN)  { taosPrintLog("TDB WARN ", 255, __VA_ARGS__); }}
-#define tsdbInfo(...)  { if (tsdbDebugFlag & DEBUG_INFO)  { taosPrintLog("TDB ", 255, __VA_ARGS__); }}
-#define tsdbDebug(...) { if (tsdbDebugFlag & DEBUG_DEBUG) { taosPrintLog("TDB ", tsdbDebugFlag, __VA_ARGS__); }}
-#define tsdbTrace(...) { if (tsdbDebugFlag & DEBUG_TRACE) { taosPrintLog("TDB ", tsdbDebugFlag, __VA_ARGS__); }}
+#define tsdbFatal(...) do { if (tsdbDebugFlag & DEBUG_FATAL) { taosPrintLog("TDB FATAL ", 255, __VA_ARGS__); }}     while(0)
+#define tsdbError(...) do { if (tsdbDebugFlag & DEBUG_ERROR) { taosPrintLog("TDB ERROR ", 255, __VA_ARGS__); }}     while(0)
+#define tsdbWarn(...)  do { if (tsdbDebugFlag & DEBUG_WARN)  { taosPrintLog("TDB WARN ", 255, __VA_ARGS__); }}      while(0)
+#define tsdbInfo(...)  do { if (tsdbDebugFlag & DEBUG_INFO)  { taosPrintLog("TDB ", 255, __VA_ARGS__); }}           while(0)
+#define tsdbDebug(...) do { if (tsdbDebugFlag & DEBUG_DEBUG) { taosPrintLog("TDB ", tsdbDebugFlag, __VA_ARGS__); }} while(0)
+#define tsdbTrace(...) do { if (tsdbDebugFlag & DEBUG_TRACE) { taosPrintLog("TDB ", tsdbDebugFlag, __VA_ARGS__); }} while(0)
 
 #define TSDB_MAX_TABLE_SCHEMAS 16
-#define TSDB_FILE_HEAD_SIZE 512
-#define TSDB_FILE_DELIMITER 0xF00AFA0F
-#define TSDB_FILE_INIT_MAGIC 0xFFFFFFFF
+#define TSDB_FILE_HEAD_SIZE    512
+#define TSDB_FILE_DELIMITER    0xF00AFA0F
+#define TSDB_FILE_INIT_MAGIC   0xFFFFFFFF
 
 #define TAOS_IN_RANGE(key, keyMin, keyLast) (((key) >= (keyMin)) && ((key) <= (keyMax)))
 

src/tsdb/src/tsdbRead.c

@@ -956,9 +956,9 @@ static int32_t loadFileDataBlock(STsdbQueryHandle* pQueryHandle, SCompBlock* pBl
         return code;
       }
 
-      SDataCols* pTSCol = pQueryHandle->rhelper.pDataCols[0];
+      SDataCols* pTsCol = pQueryHandle->rhelper.pDataCols[0];
       if (pCheckInfo->lastKey < pBlock->keyLast) {
-        cur->pos = binarySearchForKey(pTSCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey, pQueryHandle->order);
+        cur->pos = binarySearchForKey(pTsCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey, pQueryHandle->order);
       } else {
         cur->pos = pBlock->numOfRows - 1;
       }
@@ -1704,7 +1704,32 @@ static int32_t createDataBlocksInfo(STsdbQueryHandle* pQueryHandle, int32_t numO
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t getDataBlocksInFilesImpl(STsdbQueryHandle* pQueryHandle, bool* exists) {
+static int32_t getFirstFileDataBlock(STsdbQueryHandle* pQueryHandle, bool* exists);
+
+static int32_t getDataBlockRv(STsdbQueryHandle* pQueryHandle, STableBlockInfo* pNext, bool *exists) {
+  int32_t step = ASCENDING_TRAVERSE(pQueryHandle->order)? 1 : -1;
+  SQueryFilePos* cur = &pQueryHandle->cur;
+
+  while(1) {
+    int32_t code = loadFileDataBlock(pQueryHandle, pNext->compBlock, pNext->pTableCheckInfo, exists);
+    if (code != TSDB_CODE_SUCCESS || *exists) {
+      return code;
+    }
+
+    if ((cur->slot == pQueryHandle->numOfBlocks - 1 && ASCENDING_TRAVERSE(pQueryHandle->order)) ||
+        (cur->slot == 0 && !ASCENDING_TRAVERSE(pQueryHandle->order))) {
+      // all data blocks in current file has been checked already, try next file if exists
+      return getFirstFileDataBlock(pQueryHandle, exists);
+    } else {  // next block of the same file
+      cur->slot += step;
+      cur->mixBlock = false;
+      cur->blockCompleted = false;
+      pNext = &pQueryHandle->pDataBlockInfo[cur->slot];
+    }
+  }
+}
+
+static int32_t getFirstFileDataBlock(STsdbQueryHandle* pQueryHandle, bool* exists) {
   pQueryHandle->numOfBlocks = 0;
   SQueryFilePos* cur = &pQueryHandle->cur;
 
@@ -1789,7 +1814,23 @@ static int32_t getDataBlocksInFilesImpl(STsdbQueryHandle* pQueryHandle, bool* ex
   cur->fid = pQueryHandle->pFileGroup->fileId;
 
   STableBlockInfo* pBlockInfo = &pQueryHandle->pDataBlockInfo[cur->slot];
-  return loadFileDataBlock(pQueryHandle, pBlockInfo->compBlock, pBlockInfo->pTableCheckInfo, exists);
+  return getDataBlockRv(pQueryHandle, pBlockInfo, exists);
+}
+
+static bool isEndFileDataBlock(SQueryFilePos* cur, int32_t numOfBlocks, bool ascTrav) {
+  assert(cur != NULL && numOfBlocks > 0);
+  return (cur->slot == numOfBlocks - 1 && ascTrav) || (cur->slot == 0 && !ascTrav);
+}
+
+static void moveToNextDataBlockInCurrentFile(STsdbQueryHandle* pQueryHandle) {
+  int32_t step = ASCENDING_TRAVERSE(pQueryHandle->order)? 1 : -1;
+
+  SQueryFilePos* cur = &pQueryHandle->cur;
+  assert(cur->slot < pQueryHandle->numOfBlocks && cur->slot >= 0);
+
+  cur->slot += step;
+  cur->mixBlock       = false;
+  cur->blockCompleted = false;
 }
 
 static int32_t getDataBlocksInFiles(STsdbQueryHandle* pQueryHandle, bool* exists) {
@@ -1800,14 +1841,14 @@ static int32_t getDataBlocksInFiles(STsdbQueryHandle* pQueryHandle, bool* exists
   if (!pQueryHandle->locateStart) {
     pQueryHandle->locateStart = true;
     STsdbCfg* pCfg = &pQueryHandle->pTsdb->config;
-    int32_t fid = getFileIdFromKey(pQueryHandle->window.skey, pCfg->daysPerFile, pCfg->precision);
+    int32_t   fid = getFileIdFromKey(pQueryHandle->window.skey, pCfg->daysPerFile, pCfg->precision);
 
     pthread_rwlock_rdlock(&pQueryHandle->pTsdb->tsdbFileH->fhlock);
     tsdbInitFileGroupIter(pFileHandle, &pQueryHandle->fileIter, pQueryHandle->order);
     tsdbSeekFileGroupIter(&pQueryHandle->fileIter, fid);
     pthread_rwlock_unlock(&pQueryHandle->pTsdb->tsdbFileH->fhlock);
 
-    return getDataBlocksInFilesImpl(pQueryHandle, exists);
+    return getFirstFileDataBlock(pQueryHandle, exists);
   } else {
     // check if current file block is all consumed
     STableBlockInfo* pBlockInfo = &pQueryHandle->pDataBlockInfo[cur->slot];
@@ -1815,27 +1856,26 @@ static int32_t getDataBlocksInFiles(STsdbQueryHandle* pQueryHandle, bool* exists
 
     // current block is done, try next
     if ((!cur->mixBlock) || cur->blockCompleted) {
-      if ((cur->slot == pQueryHandle->numOfBlocks - 1 && ASCENDING_TRAVERSE(pQueryHandle->order)) ||
-          (cur->slot == 0 && !ASCENDING_TRAVERSE(pQueryHandle->order))) {
-        // all data blocks in current file has been checked already, try next file if exists
-        return getDataBlocksInFilesImpl(pQueryHandle, exists);
-      } else {
-        // next block of the same file
-        int32_t step = ASCENDING_TRAVERSE(pQueryHandle->order) ? 1 : -1;
-        cur->slot += step;
-
-        cur->mixBlock = false;
-        cur->blockCompleted = false;
-
-        STableBlockInfo* pNext = &pQueryHandle->pDataBlockInfo[cur->slot];
-        return loadFileDataBlock(pQueryHandle, pNext->compBlock, pNext->pTableCheckInfo, exists);
-      }
+      // all data blocks in current file has been checked already, try next file if exists
     } else {
-      tsdbDebug("%p continue in current data block, index:%d, pos:%d, %p", pQueryHandle, cur->slot, cur->pos, pQueryHandle->qinfo);
+      tsdbDebug("%p continue in current data block, index:%d, pos:%d, %p", pQueryHandle, cur->slot, cur->pos,
+                pQueryHandle->qinfo);
       int32_t code = handleDataMergeIfNeeded(pQueryHandle, pBlockInfo->compBlock, pCheckInfo);
-      *exists = pQueryHandle->realNumOfRows > 0;
+      *exists = (pQueryHandle->realNumOfRows > 0);
 
-      return code;
+      if (code != TSDB_CODE_SUCCESS || *exists) {
+        return code;
+      }
+    }
+
+    // current block is empty, try next block in file
+    // all data blocks in current file has been checked already, try next file if exists
+    if (isEndFileDataBlock(cur, pQueryHandle->numOfBlocks, ASCENDING_TRAVERSE(pQueryHandle->order))) {
+      return getFirstFileDataBlock(pQueryHandle, exists);
+    } else {
+      moveToNextDataBlockInCurrentFile(pQueryHandle);
+      STableBlockInfo* pNext = &pQueryHandle->pDataBlockInfo[cur->slot];
+      return getDataBlockRv(pQueryHandle, pNext, exists);
     }
   }
 }

src/util/src/tcache.c

@@ -547,13 +547,14 @@ void taosAddToTrashcan(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
     return;
   }
 
+  __cache_wr_lock(pCacheObj);
   STrashElem *pElem = calloc(1, sizeof(STrashElem));
   pElem->pData = pNode;
-  pElem->prev  = NULL;
+  pElem->prev = NULL;
+  pElem->next = NULL;
   pNode->inTrashcan = true;
   pNode->pTNodeHeader = pElem;
 
-  __cache_wr_lock(pCacheObj);
   pElem->next = pCacheObj->pTrash;
   if (pCacheObj->pTrash) {
     pCacheObj->pTrash->prev = pElem;
@@ -563,8 +564,8 @@ void taosAddToTrashcan(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
   pCacheObj->numOfElemsInTrash++;
   __cache_unlock(pCacheObj);
 
-  uDebug("cache:%s key:%p, %p move to trashcan, pTrashElem:%p, numOfElem in trashcan:%d", pCacheObj->name,
-      pNode->key, pNode->data, pElem, pCacheObj->numOfElemsInTrash);
+  uDebug("cache:%s key:%p, %p move to trashcan, pTrashElem:%p, numOfElem in trashcan:%d", pCacheObj->name, pNode->key,
+         pNode->data, pElem, pCacheObj->numOfElemsInTrash);
 }
 
 void taosTrashcanEmpty(SCacheObj *pCacheObj, bool force) {

src/util/src/tskiplist.c

@@ -280,10 +280,13 @@ bool tSkipListIterNext(SSkipListIterator *iter) {
   tSkipListRLock(pSkipList);
 
   if (iter->order == TSDB_ORDER_ASC) {
-    if (iter->cur == pSkipList->pTail) {
+    // no data in the skip list
+    if (iter->cur == pSkipList->pTail || iter->next == NULL) {
+      iter->cur = pSkipList->pTail;
       tSkipListUnlock(pSkipList);
       return false;
     }
+
     iter->cur = SL_NODE_GET_FORWARD_POINTER(iter->cur, 0);
 
     // a new node is inserted into between iter->cur and iter->next, ignore it
@@ -295,9 +298,11 @@ bool tSkipListIterNext(SSkipListIterator *iter) {
     iter->step++;
   } else {
     if (iter->cur == pSkipList->pHead) {
+      iter->cur = pSkipList->pHead;
       tSkipListUnlock(pSkipList);
       return false;
     }
+
     iter->cur = SL_NODE_GET_BACKWARD_POINTER(iter->cur, 0);
 
     // a new node is inserted into between iter->cur and iter->next, ignore it

tests/script/general/parser/mixed_blocks.sim

@@ -144,4 +144,20 @@ if $data03 != 319 then
   return -1
 endi
 
-system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file
+print ===================> TD-2488
+sql create table m1(ts timestamp, k int) tags(a int);
+sql create table t1 using m1 tags(1);
+sql create table t2 using m1 tags(2);
+sql insert into t1 values('2020-1-1 1:1:1', 1);
+sql insert into t1 values('2020-1-1 1:10:1', 2);
+sql insert into t2 values('2020-1-1 1:5:1', 99);
+
+print ================== restart server to commit data into disk
+system sh/exec.sh -n dnode1 -s stop -x SIGINT
+sleep 3000
+system sh/exec.sh -n dnode1 -s start
+print ================== server restart completed
+sql select ts from m1 where ts='2020-1-1 1:5:1'
+if $rows != 1 then
+  return -1
+endi
\ No newline at end of file