Merge pull request #1608 from taosdata/feature/query

Feature/query

src/client/src/tscFunctionImpl.c

@@ -3578,121 +3578,6 @@ void spread_function_finalizer(SQLFunctionCtx *pCtx) {
   doFinalizer(pCtx);
 }
 
-/*
- * Compare two strings
- *    TSDB_MATCH:            Match
- *    TSDB_NOMATCH:          No match
- *    TSDB_NOWILDCARDMATCH:  No match in spite of having * or % wildcards.
- * Like matching rules:
- *      '%': Matches zero or more characters
- *      '_': Matches one character
- *
- */
-int patternMatch(const char *patterStr, const char *str, size_t size, const SPatternCompareInfo *pInfo) {
-  char c, c1;
-  
-  int32_t i = 0;
-  int32_t j = 0;
-  
-  while ((c = patterStr[i++]) != 0) {
-    if (c == pInfo->matchAll) { /* Match "*" */
-      
-      while ((c = patterStr[i++]) == pInfo->matchAll || c == pInfo->matchOne) {
-        if (c == pInfo->matchOne && (j > size || str[j++] == 0)) {
-          // empty string, return not match
-          return TSDB_PATTERN_NOWILDCARDMATCH;
-        }
-      }
-      
-      if (c == 0) {
-        return TSDB_PATTERN_MATCH; /* "*" at the end of the pattern matches */
-      }
-      
-      char next[3] = {toupper(c), tolower(c), 0};
-      while (1) {
-        size_t n = strcspn(str, next);
-        str += n;
-        
-        if (str[0] == 0 || (n >= size - 1)) {
-          break;
-        }
-        
-        int32_t ret = patternMatch(&patterStr[i], ++str, size - n - 1, pInfo);
-        if (ret != TSDB_PATTERN_NOMATCH) {
-          return ret;
-        }
-      }
-      return TSDB_PATTERN_NOWILDCARDMATCH;
-    }
-    
-    c1 = str[j++];
-    
-    if (j <= size) {
-      if (c == c1 || tolower(c) == tolower(c1) || (c == pInfo->matchOne && c1 != 0)) {
-        continue;
-      }
-    }
-    
-    return TSDB_PATTERN_NOMATCH;
-  }
-  
-  return (str[j] == 0 || j >= size) ? TSDB_PATTERN_MATCH : TSDB_PATTERN_NOMATCH;
-}
-
-int WCSPatternMatch(const wchar_t *patterStr, const wchar_t *str, size_t size, const SPatternCompareInfo *pInfo) {
-  wchar_t c, c1;
-  wchar_t matchOne = L'_';  // "_"
-  wchar_t matchAll = L'%';  // "%"
-  
-  int32_t i = 0;
-  int32_t j = 0;
-  
-  while ((c = patterStr[i++]) != 0) {
-    if (c == matchAll) { /* Match "%" */
-      
-      while ((c = patterStr[i++]) == matchAll || c == matchOne) {
-        if (c == matchOne && (j > size || str[j++] == 0)) {
-          return TSDB_PATTERN_NOWILDCARDMATCH;
-        }
-      }
-      if (c == 0) {
-        return TSDB_PATTERN_MATCH;
-      }
-      
-      wchar_t accept[3] = {towupper(c), towlower(c), 0};
-      while (1) {
-        size_t n = wcsspn(str, accept);
-        
-        str += n;
-        if (str[0] == 0 || (n >= size - 1)) {
-          break;
-        }
-        
-        str++;
-        
-        int32_t ret = WCSPatternMatch(&patterStr[i], str, wcslen(str), pInfo);
-        if (ret != TSDB_PATTERN_NOMATCH) {
-          return ret;
-        }
-      }
-      
-      return TSDB_PATTERN_NOWILDCARDMATCH;
-    }
-    
-    c1 = str[j++];
-    
-    if (j <= size) {
-      if (c == c1 || towlower(c) == towlower(c1) || (c == matchOne && c1 != 0)) {
-        continue;
-      }
-    }
-    
-    return TSDB_PATTERN_NOMATCH;
-  }
-  
-  return (str[j] == 0 || j >= size) ? TSDB_PATTERN_MATCH : TSDB_PATTERN_NOMATCH;
-}
-
 static void getStatics_i8(int64_t *primaryKey, int32_t type, int8_t *data, int32_t numOfRow, int64_t *min, int64_t *max,
                           int64_t *sum, int16_t *minIndex, int16_t *maxIndex, int32_t *numOfNull) {
   *min = INT64_MAX;

src/client/src/tscSQLParser.c

@@ -30,6 +30,7 @@
 #include "ttokendef.h"
 
 #include "name.h"
+#include "tcompare.h"
 
 #define DEFAULT_PRIMARY_TIMESTAMP_COL_NAME "_c0"
 

src/mnode/src/mgmtTable.c

@@ -15,19 +15,13 @@
 
 #define _DEFAULT_SOURCE
 #include "os.h"
+
 #include "taosmsg.h"
-#include "tscompression.h"
-#include "tskiplist.h"
 #include "ttime.h"
 #include "tutil.h"
-#include "qast.h"
-#include "qextbuffer.h"
 #include "taoserror.h"
 #include "taosmsg.h"
 #include "tscompression.h"
-#include "tskiplist.h"
-#include "tsqlfunction.h"
-#include "ttime.h"
 #include "name.h"
 #include "taccount.h"
 #include "mgmtDClient.h"
@@ -42,6 +36,7 @@
 #include "mgmtTable.h"
 #include "mgmtUser.h"
 #include "mgmtVgroup.h"
+#include "tcompare.h"
 
 void *  tsChildTableSdb;
 void *  tsSuperTableSdb;

src/query/inc/queryExecutor.h

@@ -160,7 +160,7 @@ typedef struct SQueryRuntimeEnv {
   SQueryCostSummary  summary;
   bool               stableQuery;  // super table query or not
   void*              pQueryHandle;
-
+  void*              pSecQueryHandle; // another thread for
   SDiskbasedResultBuf* pResultBuf;  // query result buffer based on blocked-wised disk file
 } SQueryRuntimeEnv;
 
@@ -172,6 +172,8 @@ typedef struct SQInfo {
   int32_t          code;          // error code to returned to client
   sem_t            dataReady;
   SArray*          pTableIdList;  // table id list
+  void*            tsdb;
+  
   SQueryRuntimeEnv runtimeEnv;
   int32_t          subgroupIdx;
   int32_t          offset; /* offset in group result set of subgroup */

src/query/inc/tsqlfunction.h

@@ -79,17 +79,10 @@ extern "C" {
 #define TSDB_BASE_FUNC_SO TSDB_FUNCSTATE_SO | TSDB_FUNCSTATE_STREAM | TSDB_FUNCSTATE_METRIC | TSDB_FUNCSTATE_OF
 #define TSDB_BASE_FUNC_MO TSDB_FUNCSTATE_MO | TSDB_FUNCSTATE_STREAM | TSDB_FUNCSTATE_METRIC | TSDB_FUNCSTATE_OF
 
-#define TSDB_PATTERN_MATCH            0
-#define TSDB_PATTERN_NOMATCH          1
-#define TSDB_PATTERN_NOWILDCARDMATCH  2
-#define TSDB_PATTERN_STRING_MAX_LEN   20
 
 #define TSDB_FUNCTIONS_NAME_MAX_LENGTH 16
 #define TSDB_AVG_FUNCTION_INTER_BUFFER_SIZE 50
 
-#define PATTERN_COMPARE_INFO_INITIALIZER \
-  { '%', '_' }
-
 #define DATA_SET_FLAG ','  // to denote the output area has data, not null value
 #define DATA_SET_FLAG_SIZE sizeof(DATA_SET_FLAG)
 
@@ -222,20 +215,11 @@ typedef struct SQLAggFuncElem {
   int32_t (*dataReqFunc)(SQLFunctionCtx *pCtx, TSKEY start, TSKEY end, int32_t colId);
 } SQLAggFuncElem;
 
-typedef struct SPatternCompareInfo {
-  char matchAll;  // symbol for match all wildcard, default: '%'
-  char matchOne;  // symbol for match one wildcard, default: '_'
-} SPatternCompareInfo;
-
 #define GET_RES_INFO(ctx) ((ctx)->resultInfo)
 
 int32_t getResultDataInfo(int32_t dataType, int32_t dataBytes, int32_t functionId, int32_t param, int16_t *type,
                           int16_t *len, int16_t *interResBytes, int16_t extLength, bool isSuperTable);
 
-int patternMatch(const char *zPattern, const char *zString, size_t size, const SPatternCompareInfo *pInfo);
-
-int WCSPatternMatch(const wchar_t *zPattern, const wchar_t *zString, size_t size, const SPatternCompareInfo *pInfo);
-
 #define IS_STREAM_QUERY_VALID(x)  (((x)&TSDB_FUNCSTATE_STREAM) != 0)
 #define IS_MULTIOUTPUT(x)         (((x)&TSDB_FUNCSTATE_MO) != 0)
 #define IS_SINGLEOUTPUT(x)        (((x)&TSDB_FUNCSTATE_SO) != 0)

src/query/src/queryExecutor.c

@@ -362,10 +362,10 @@ bool isTSCompQuery(SQuery *pQuery) { return pQuery->pSelectExpr[0].pBase.functio
 bool doRevisedResultsByLimit(SQInfo *pQInfo) {
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
 
-  if ((pQuery->limit.limit > 0) && (pQuery->rec.rows + pQuery->rec.rows > pQuery->limit.limit)) {
-    pQuery->rec.rows = pQuery->limit.limit - pQuery->rec.rows;
-
-    // query completed
+  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);
+    
     setQueryStatus(pQuery, QUERY_COMPLETED);
     return true;
   }
@@ -1552,6 +1552,8 @@ static void teardownQueryRuntimeEnv(SQueryRuntimeEnv *pRuntimeEnv) {
 
   destroyResultBuf(pRuntimeEnv->pResultBuf);
   tsdbCleanupQueryHandle(pRuntimeEnv->pQueryHandle);
+  tsdbCleanupQueryHandle(pRuntimeEnv->pSecQueryHandle);
+  
   pRuntimeEnv->pTSBuf = tsBufDestory(pRuntimeEnv->pTSBuf);
 }
 
@@ -2501,17 +2503,20 @@ SArray *loadDataBlockOnDemand(SQueryRuntimeEnv *pRuntimeEnv, SDataBlockInfo *pBl
 }
 
 int32_t binarySearchForKey(char *pValue, int num, TSKEY key, int order) {
-  int    firstPos, lastPos, midPos = -1;
-  int    numOfPoints;
-  TSKEY *keyList;
+  int32_t midPos = -1;
+  int32_t numOfPoints;
 
-  if (num <= 0) return -1;
+  if (num <= 0) {
+    return -1;
+  }
 
-  keyList = (TSKEY *)pValue;
-  firstPos = 0;
-  lastPos = num - 1;
+  assert(order == TSDB_ORDER_ASC || order == TSDB_ORDER_DESC);
+  
+  TSKEY* keyList   = (TSKEY *)pValue;
+  int32_t firstPos = 0;
+  int32_t lastPos  = num - 1;
 
-  if (order == 0) {
+  if (order == TSDB_ORDER_DESC) {
     // find the first position which is smaller than the key
     while (1) {
       if (key >= keyList[lastPos]) return lastPos;
@@ -2565,7 +2570,7 @@ static int64_t doScanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
   dTrace("QInfo:%p query start, qrange:%" PRId64 "-%" PRId64 ", lastkey:%" PRId64 ", order:%d",
          GET_QINFO_ADDR(pRuntimeEnv), pQuery->window.skey, pQuery->window.ekey, pQuery->lastKey, pQuery->order.order);
 
-  tsdb_query_handle_t pQueryHandle = pRuntimeEnv->pQueryHandle;
+  tsdb_query_handle_t pQueryHandle = pRuntimeEnv->scanFlag == MASTER_SCAN? pRuntimeEnv->pQueryHandle:pRuntimeEnv->pSecQueryHandle;
   while (tsdbNextDataBlock(pQueryHandle)) {
     
     if (isQueryKilled(GET_QINFO_ADDR(pRuntimeEnv))) {
@@ -3520,8 +3525,9 @@ void scanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
   setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
 
   // store the start query position
-  void *pos = tsdbDataBlockTell(pRuntimeEnv->pQueryHandle);
-
+//  void *pos = tsdbDataBlockTell(pRuntimeEnv->pQueryHandle);
+  SQInfo* pQInfo = (SQInfo*) GET_QINFO_ADDR(pRuntimeEnv);
+  
   int64_t skey = pQuery->lastKey;
   int32_t status = pQuery->status;
   int32_t activeSlot = pRuntimeEnv->windowResInfo.curIndex;
@@ -3543,15 +3549,32 @@ void scanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
     }
 
     // set the correct start position, and load the corresponding block in buffer for next round scan all data blocks.
-    /*int32_t ret =*/ tsdbDataBlockSeek(pRuntimeEnv->pQueryHandle, pos);
-
+//    /*int32_t ret =*/ tsdbDataBlockSeek(pRuntimeEnv->pQueryHandle, pos);
+  
+    STsdbQueryCond cond = {
+        .twindow = {pQuery->window.skey, pQuery->lastKey},
+        .order   = pQuery->order.order,
+        .colList = pQuery->colList,
+    };
+  
+    SArray *cols = taosArrayInit(pQuery->numOfCols, sizeof(pQuery->colList[0]));
+    for (int32_t i = 0; i < pQuery->numOfCols; ++i) {
+      taosArrayPush(cols, &pQuery->colList[i]);
+    }
+  
+    if (pRuntimeEnv->pSecQueryHandle != NULL) {
+      pRuntimeEnv->pSecQueryHandle = tsdbQueryByTableId(pQInfo->tsdb, &cond, pQInfo->pTableIdList, cols);
+    }
+    
+    taosArrayDestroy(cols);
+  
     status = pQuery->status;
     pRuntimeEnv->windowResInfo.curIndex = activeSlot;
 
     setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
     pRuntimeEnv->scanFlag = REPEAT_SCAN;
 
-    /* check if query is killed or not */
+    // check if query is killed or not
     if (isQueryKilled(GET_QINFO_ADDR(pRuntimeEnv))) {
       return;
     }
@@ -4179,6 +4202,7 @@ int32_t doInitQInfo(SQInfo *pQInfo, void *param, void* tsdb, bool isSTableQuery)
   
   pRuntimeEnv->pQueryHandle = tsdbQueryByTableId(tsdb, &cond, pQInfo->pTableIdList, cols);
   taosArrayDestroy(cols);
+  pQInfo->tsdb = tsdb;
   
   pRuntimeEnv->pQuery = pQuery;
   pRuntimeEnv->pTSBuf = param;
@@ -4972,7 +4996,6 @@ static void tableIntervalProcessImpl(SQueryRuntimeEnv *pRuntimeEnv) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
 
   while (1) {
-//    initCtxOutputBuf(pRuntimeEnv);
     scanAllDataBlocks(pRuntimeEnv);
 
     if (isQueryKilled(GET_QINFO_ADDR(pRuntimeEnv))) {

src/util/inc/tcompare.h

@@ -16,8 +16,24 @@
 #ifndef TDENGINE_TCOMPARE_H
 #define TDENGINE_TCOMPARE_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "os.h"
 
+#define TSDB_PATTERN_MATCH 0
+#define TSDB_PATTERN_NOMATCH 1
+#define TSDB_PATTERN_NOWILDCARDMATCH 2
+#define TSDB_PATTERN_STRING_MAX_LEN 20
+
+#define PATTERN_COMPARE_INFO_INITIALIZER { '%', '_' }
+
+typedef struct SPatternCompareInfo {
+  char matchAll;  // symbol for match all wildcard, default: '%'
+  char matchOne;  // symbol for match one wildcard, default: '_'
+} SPatternCompareInfo;
+
 int32_t compareInt32Val(const void *pLeft, const void *pRight);
 
 int32_t compareInt64Val(const void *pLeft, const void *pRight);
@@ -36,8 +52,16 @@ int32_t compareStrVal(const void *pLeft, const void *pRight);
 
 int32_t compareWStrVal(const void *pLeft, const void *pRight);
 
+int patternMatch(const char *zPattern, const char *zString, size_t size, const SPatternCompareInfo *pInfo);
+
+int WCSPatternMatch(const wchar_t *zPattern, const wchar_t *zString, size_t size, const SPatternCompareInfo *pInfo);
+
 __compar_fn_t getKeyComparFunc(int32_t keyType);
 
 __compar_fn_t getComparFunc(int32_t type, int32_t filterDataType);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // TDENGINE_TCOMPARE_H

src/util/src/tcompare.c

 #include "taosdef.h"
 #include "tcompare.h"
 
+#include "tutil.h"
+
 int32_t compareInt32Val(const void *pLeft, const void *pRight) {
   int32_t ret = GET_INT32_VAL(pLeft) - GET_INT32_VAL(pRight);
   if (ret == 0) {
@@ -11,7 +13,7 @@ int32_t compareInt32Val(const void *pLeft, const void *pRight) {
 }
 
 int32_t compareInt64Val(const void *pLeft, const void *pRight) {
-  int32_t ret = GET_INT64_VAL(pLeft) - GET_INT64_VAL(pRight);
+  int64_t ret = GET_INT64_VAL(pLeft) - GET_INT64_VAL(pRight);
   if (ret == 0) {
     return 0;
   } else {
@@ -102,6 +104,143 @@ int32_t compareWStrVal(const void *pLeft, const void *pRight) {
   return 0;
 }
 
+/*
+ * Compare two strings
+ *    TSDB_MATCH:            Match
+ *    TSDB_NOMATCH:          No match
+ *    TSDB_NOWILDCARDMATCH:  No match in spite of having * or % wildcards.
+ * Like matching rules:
+ *      '%': Matches zero or more characters
+ *      '_': Matches one character
+ *
+ */
+int patternMatch(const char *patterStr, const char *str, size_t size, const SPatternCompareInfo *pInfo) {
+  char c, c1;
+  
+  int32_t i = 0;
+  int32_t j = 0;
+  
+  while ((c = patterStr[i++]) != 0) {
+    if (c == pInfo->matchAll) { /* Match "*" */
+      
+      while ((c = patterStr[i++]) == pInfo->matchAll || c == pInfo->matchOne) {
+        if (c == pInfo->matchOne && (j > size || str[j++] == 0)) {
+          // empty string, return not match
+          return TSDB_PATTERN_NOWILDCARDMATCH;
+        }
+      }
+      
+      if (c == 0) {
+        return TSDB_PATTERN_MATCH; /* "*" at the end of the pattern matches */
+      }
+      
+      char next[3] = {toupper(c), tolower(c), 0};
+      while (1) {
+        size_t n = strcspn(str, next);
+        str += n;
+        
+        if (str[0] == 0 || (n >= size - 1)) {
+          break;
+        }
+        
+        int32_t ret = patternMatch(&patterStr[i], ++str, size - n - 1, pInfo);
+        if (ret != TSDB_PATTERN_NOMATCH) {
+          return ret;
+        }
+      }
+      return TSDB_PATTERN_NOWILDCARDMATCH;
+    }
+    
+    c1 = str[j++];
+    
+    if (j <= size) {
+      if (c == c1 || tolower(c) == tolower(c1) || (c == pInfo->matchOne && c1 != 0)) {
+        continue;
+      }
+    }
+    
+    return TSDB_PATTERN_NOMATCH;
+  }
+  
+  return (str[j] == 0 || j >= size) ? TSDB_PATTERN_MATCH : TSDB_PATTERN_NOMATCH;
+}
+
+int WCSPatternMatch(const wchar_t *patterStr, const wchar_t *str, size_t size, const SPatternCompareInfo *pInfo) {
+  wchar_t c, c1;
+  wchar_t matchOne = L'_';  // "_"
+  wchar_t matchAll = L'%';  // "%"
+  
+  int32_t i = 0;
+  int32_t j = 0;
+  
+  while ((c = patterStr[i++]) != 0) {
+    if (c == matchAll) { /* Match "%" */
+      
+      while ((c = patterStr[i++]) == matchAll || c == matchOne) {
+        if (c == matchOne && (j > size || str[j++] == 0)) {
+          return TSDB_PATTERN_NOWILDCARDMATCH;
+        }
+      }
+      if (c == 0) {
+        return TSDB_PATTERN_MATCH;
+      }
+      
+      wchar_t accept[3] = {towupper(c), towlower(c), 0};
+      while (1) {
+        size_t n = wcsspn(str, accept);
+        
+        str += n;
+        if (str[0] == 0 || (n >= size - 1)) {
+          break;
+        }
+        
+        str++;
+        
+        int32_t ret = WCSPatternMatch(&patterStr[i], str, wcslen(str), pInfo);
+        if (ret != TSDB_PATTERN_NOMATCH) {
+          return ret;
+        }
+      }
+      
+      return TSDB_PATTERN_NOWILDCARDMATCH;
+    }
+    
+    c1 = str[j++];
+    
+    if (j <= size) {
+      if (c == c1 || towlower(c) == towlower(c1) || (c == matchOne && c1 != 0)) {
+        continue;
+      }
+    }
+    
+    return TSDB_PATTERN_NOMATCH;
+  }
+  
+  return (str[j] == 0 || j >= size) ? TSDB_PATTERN_MATCH : TSDB_PATTERN_NOMATCH;
+}
+
+static UNUSED_FUNC int32_t compareStrPatternComp(const void* pLeft, const void* pRight) {
+  SPatternCompareInfo pInfo = {'%', '_'};
+  
+  const char* pattern = pRight;
+  const char* str = pLeft;
+  
+  int32_t ret = patternMatch(pattern, str, strlen(str), &pInfo);
+  
+  return (ret == TSDB_PATTERN_MATCH) ? 0 : 1;
+}
+
+static UNUSED_FUNC int32_t compareWStrPatternComp(const void* pLeft, const void* pRight) {
+  SPatternCompareInfo pInfo = {'%', '_'};
+  
+  const wchar_t* pattern = pRight;
+  const wchar_t* str = pLeft;
+  
+  int32_t ret = WCSPatternMatch(pattern, str, wcslen(str), &pInfo);
+  
+  return (ret == TSDB_PATTERN_MATCH) ? 0 : 1;
+}
+
 __compar_fn_t getComparFunc(int32_t type, int32_t filterDataType) {
   __compar_fn_t comparFn = NULL;
   
@@ -109,8 +248,9 @@ __compar_fn_t getComparFunc(int32_t type, int32_t filterDataType) {
     case TSDB_DATA_TYPE_TINYINT:
     case TSDB_DATA_TYPE_SMALLINT:
     case TSDB_DATA_TYPE_INT:
-    case TSDB_DATA_TYPE_BIGINT: {
-      if (filterDataType == TSDB_DATA_TYPE_BIGINT) {
+    case TSDB_DATA_TYPE_BIGINT:
+    case TSDB_DATA_TYPE_TIMESTAMP: {
+      if (filterDataType == TSDB_DATA_TYPE_BIGINT || filterDataType == TSDB_DATA_TYPE_TIMESTAMP) {
         comparFn = compareInt64Val;
         break;
       }

src/util/src/tskiplist.c

@@ -75,53 +75,6 @@ static void tSkipListDoInsert(SSkipList *pSkipList, SSkipListNode **forward, SSk
 static SSkipListNode* tSkipListDoAppend(SSkipList *pSkipList, SSkipListNode *pNode);
 static SSkipListIterator* doCreateSkipListIterator(SSkipList *pSkipList, int32_t order);
 
-//static __compar_fn_t getComparFunc(SSkipList *pSkipList, int32_t filterDataType) {
-//  __compar_fn_t comparFn = NULL;
-//
-//  switch (pSkipList->keyInfo.type) {
-//    case TSDB_DATA_TYPE_TINYINT:
-//    case TSDB_DATA_TYPE_SMALLINT:
-//    case TSDB_DATA_TYPE_INT:
-//    case TSDB_DATA_TYPE_BIGINT: {
-//      if (filterDataType == TSDB_DATA_TYPE_BIGINT) {
-//        comparFn = compareInt64Val;
-//        break;
-//      }
-//    }
-//    case TSDB_DATA_TYPE_BOOL: {
-//      if (filterDataType >= TSDB_DATA_TYPE_BOOL && filterDataType <= TSDB_DATA_TYPE_BIGINT) {
-//        comparFn = compareInt32Val;
-//      } else if (filterDataType >= TSDB_DATA_TYPE_FLOAT && filterDataType <= TSDB_DATA_TYPE_DOUBLE) {
-//        comparFn = compareIntDoubleVal;
-//      }
-//      break;
-//    }
-//    case TSDB_DATA_TYPE_FLOAT:
-//    case TSDB_DATA_TYPE_DOUBLE: {
-////      if (filterDataType >= TSDB_DATA_TYPE_BOOL && filterDataType <= TSDB_DATA_TYPE_BIGINT) {
-////        comparFn = compareDoubleIntVal;
-////      } else if (filterDataType >= TSDB_DATA_TYPE_FLOAT && filterDataType <= TSDB_DATA_TYPE_DOUBLE) {
-////        comparFn = compareDoubleVal;
-////      }
-//      if (filterDataType == TSDB_DATA_TYPE_DOUBLE) {
-//        comparFn = compareDoubleVal;
-//      }
-//      break;
-//    }
-//    case TSDB_DATA_TYPE_BINARY:
-//      comparFn = compareStrVal;
-//      break;
-//    case TSDB_DATA_TYPE_NCHAR:
-//      comparFn = compareWStrVal;
-//      break;
-//    default:
-//      comparFn = compareInt32Val;
-//      break;
-//  }
-//
-//  return comparFn;
-//}
-
 static bool initForwardBackwardPtr(SSkipList* pSkipList) {
   uint32_t maxLevel = pSkipList->maxLevel;
   
@@ -445,6 +398,11 @@ SSkipListIterator *tSkipListCreateIterFromVal(SSkipList* pSkipList, const char*
       iter->cur = forward[0]; // greater equals than the value
     } else {
       iter->cur = SL_GET_FORWARD_POINTER(forward[0], 0);
+
+      if (ret == 0) {
+        assert(iter->cur != pSkipList->pTail);
+        iter->cur = SL_GET_FORWARD_POINTER(iter->cur, 0);
+      }
     }
     
     return iter;