diff --git a/src/client/inc/tschemautil.h b/src/client/inc/tschemautil.h
index 99ffa4e766c42b094ff29517c70640caca674518..67942ad42a0942756efe18e44eff711df59ba1d9 100644
--- a/src/client/inc/tschemautil.h
+++ b/src/client/inc/tschemautil.h
@@ -110,8 +110,6 @@ STableMeta* tscCreateTableMetaFromMsg(STableMetaMsg* pTableMetaMsg, size_t* size
 //todo tags value as well as the table id structure needs refactor
 char *tsGetTagsValue(STableMeta *pMeta);
 
-void extractTableNameFromToken(SSQLToken *pToken, SSQLToken* pTable);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index afdad05b43e2c38ed1eae29bc755336964c149a9..0917a3b19cb6834db54fe55f0b04f4586aeb62fe 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -14,7 +14,6 @@
  */
 
 #include "os.h"
-#include "qast.h"
 #include "qextbuffer.h"
 #include "qfill.h"
 #include "qhistogram.h"
@@ -23,6 +22,7 @@
 #include "qtsbuf.h"
 #include "taosdef.h"
 #include "taosmsg.h"
+#include "qast.h"
 #include "tscLog.h"
 #include "tscSubquery.h"
 #include "tscompression.h"
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index ea88e4a935159d59a439d0f0218ef247803ea1ed..ec4f77b13e6d6ee3ecf449265f9a4c9a79ff9ff3 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -18,19 +18,19 @@
 #define _DEFAULT_SOURCE
 
 #include "os.h"
-#include "qast.h"
 #include "taos.h"
 #include "taosmsg.h"
-#include "tstoken.h"
-#include "tstrbuild.h"
-#include "ttime.h"
+#include "qast.h"
+#include "tcompare.h"
+#include "tname.h"
 #include "tscLog.h"
 #include "tscUtil.h"
 #include "tschemautil.h"
 #include "tsclient.h"
+#include "tstoken.h"
+#include "tstrbuild.h"
+#include "ttime.h"
 #include "ttokendef.h"
-#include "tname.h"
-#include "tcompare.h"
 
 #define DEFAULT_PRIMARY_TIMESTAMP_COL_NAME "_c0"
 
diff --git a/src/client/src/tscSchemaUtil.c b/src/client/src/tscSchemaUtil.c
index da06e3e5e22c7ead926339a36e79aba4317ba757..934a562387f26a95ec1508c5cfbd4633137cac9e 100644
--- a/src/client/src/tscSchemaUtil.c
+++ b/src/client/src/tscSchemaUtil.c
@@ -215,25 +215,3 @@ __attribute__ ((unused)) static FORCE_INLINE size_t copy(char* dst, const char*
   return len;
 }
 
-/*
- * tablePrefix.columnName
- * extract table name and save it in pTable, with only column name in pToken
- */
-void extractTableNameFromToken(SSQLToken* pToken, SSQLToken* pTable) {
-  const char sep = TS_PATH_DELIMITER[0];
-
-  if (pToken == pTable || pToken == NULL || pTable == NULL) {
-    return;
-  }
-
-  char* r = strnchr(pToken->z, sep, pToken->n, false);
-
-  if (r != NULL) {  // record the table name token
-    pTable->n = r - pToken->z;
-    pTable->z = pToken->z;
-
-    r += 1;
-    pToken->n -= (r - pToken->z);
-    pToken->z = r;
-  }
-}
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 47f2ba855ef5fc36ae1062f7daa849a0e04108de..b5b659de0cccf69e71ee579e404378bedbbac4d0 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -14,12 +14,12 @@
  */
 #include "os.h"
 
-#include "tscSubquery.h"
+#include "qtsbuf.h"
 #include "qast.h"
 #include "tcompare.h"
-#include "tschemautil.h"
-#include "qtsbuf.h"
 #include "tscLog.h"
+#include "tscSubquery.h"
+#include "tschemautil.h"
 #include "tsclient.h"
 
 typedef struct SInsertSupporter {
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 791073f7a8b5f00af93b5c35fc1f778907471537..ed9822eea971ea88242e46e67c40122c52f50d9d 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -14,21 +14,21 @@
  */
 
 #include "os.h"
-#include "qast.h"
+#include "hash.h"
+#include "tscUtil.h"
 #include "taosmsg.h"
+#include "qast.h"
 #include "tcache.h"
 #include "tkey.h"
 #include "tmd5.h"
-#include "tscProfile.h"
 #include "tscLocalMerge.h"
+#include "tscLog.h"
+#include "tscProfile.h"
 #include "tscSubquery.h"
 #include "tschemautil.h"
 #include "tsclient.h"
 #include "ttimer.h"
 #include "ttokendef.h"
-#include "tscLog.h"
-#include "tscUtil.h"
-#include "hash.h"
 
 static void freeQueryInfoImpl(SQueryInfo* pQueryInfo);
 static void clearAllTableMetaInfo(SQueryInfo* pQueryInfo, const char* address, bool removeFromCache);
diff --git a/src/common/inc/tname.h b/src/common/inc/tname.h
index 25f78cde7e0be769850606804f6f02de39023355..2263a5dae17095458b9ef91677795bb3858e11d4 100644
--- a/src/common/inc/tname.h
+++ b/src/common/inc/tname.h
@@ -3,6 +3,7 @@
 
 #include "os.h"
 #include "taosmsg.h"
+#include "tstoken.h"
 
 typedef struct SDataStatis {
   int16_t colId;
@@ -23,6 +24,8 @@ void extractTableName(const char *tableId, char *name);
 
 char* extractDBName(const char *tableId, char *name);
 
+void extractTableNameFromToken(SSQLToken *pToken, SSQLToken* pTable);
+
 SSchema tGetTableNameColumnSchema();
 
 bool tscValidateTableNameLength(size_t len);
diff --git a/src/query/inc/tvariant.h b/src/common/inc/tvariant.h
similarity index 100%
rename from src/query/inc/tvariant.h
rename to src/common/inc/tvariant.h
diff --git a/src/common/src/tname.c b/src/common/src/tname.c
index c8910a786728310311de76a96c18f70c0920e820..dd0107bf3816ab120ee1b195e46ef971ce78f6a0 100644
--- a/src/common/src/tname.c
+++ b/src/common/src/tname.c
@@ -105,3 +105,26 @@ int64_t taosGetIntervalStartTimestamp(int64_t startTime, int64_t slidingTime, in
   }
   return start;
 }
+
+/*
+ * tablePrefix.columnName
+ * extract table name and save it in pTable, with only column name in pToken
+ */
+void extractTableNameFromToken(SSQLToken* pToken, SSQLToken* pTable) {
+  const char sep = TS_PATH_DELIMITER[0];
+
+  if (pToken == pTable || pToken == NULL || pTable == NULL) {
+    return;
+  }
+
+  char* r = strnchr(pToken->z, sep, pToken->n, false);
+
+  if (r != NULL) {  // record the table name token
+    pTable->n = r - pToken->z;
+    pTable->z = pToken->z;
+
+    r += 1;
+    pToken->n -= (r - pToken->z);
+    pToken->z = r;
+  }
+}
diff --git a/src/query/src/tvariant.c b/src/common/src/tvariant.c
similarity index 100%
rename from src/query/src/tvariant.c
rename to src/common/src/tvariant.c
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 110cd23370baacb75e8b6ee3719e504ec346c058..5b14c4f0f48105a8b75f833fd1b58c0185b55acb 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -18,18 +18,18 @@
 #include "qfill.h"
 #include "taosmsg.h"
 
+#include "exception.h"
 #include "hash.h"
 #include "qExecutor.h"
 #include "qUtil.h"
-#include "qast.h"
 #include "qresultBuf.h"
 #include "query.h"
 #include "queryLog.h"
+#include "qast.h"
+#include "tfile.h"
 #include "tlosertree.h"
-#include "exception.h"
 #include "tscompression.h"
 #include "ttime.h"
-#include "tfile.h"
 
 /**
  * check if the primary column is load by default, otherwise, the program will
diff --git a/src/query/src/qast.c b/src/query/src/qast.c
index c7868a0ccb6c613f52ab405f9b0c959de9bd4c55..ffd339f111b717de2d5f92aab140408994b316eb 100644
--- a/src/query/src/qast.c
+++ b/src/query/src/qast.c
@@ -13,25 +13,26 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+
 #include "os.h"
-#include "tulog.h"
-#include "tutil.h"
-#include "tbuffer.h"
+
+#include "tname.h"
 #include "qast.h"
-#include "tcompare.h"
+#include "tsdb.h"
+#include "exception.h"
 #include "qsqlparser.h"
 #include "qsyntaxtreefunction.h"
 #include "taosdef.h"
 #include "taosmsg.h"
+#include "tarray.h"
+#include "tbuffer.h"
+#include "tcompare.h"
+#include "tskiplist.h"
 #include "tsqlfunction.h"
 #include "tstoken.h"
 #include "ttokendef.h"
-#include "tschemautil.h"
-#include "tarray.h"
-#include "tskiplist.h"
-#include "queryLog.h"
-#include "tsdbMain.h"
-#include "exception.h"
+#include "tulog.h"
+#include "tutil.h"
 
 /*
  *
@@ -675,8 +676,7 @@ static void tQueryIndexlessColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo,
     SSkipListNode *pNode = tSkipListIterGet(iter);
     char *         pData = SL_GET_NODE_DATA(pNode);
 
-    // todo refactor:
-    tstr *name = (*(STable **)pData)->name;
+    tstr *name = (tstr*) tsdbGetTableName(*(void**) pData);
     // todo speed up by using hash
     if (pQueryInfo->colIndex == TSDB_TBNAME_COLUMN_INDEX) {
       if (pQueryInfo->optr == TSDB_RELATION_IN) {
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index 9ebd63ba7e58149077fe4d69d85e394efe6b35c6..84c1c8e7d1f17732214e4b33d1f54f73639907a8 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -192,11 +192,6 @@ char *tsdbGetTableName(void* pTable) {
   }
 }
 
-STableId tsdbGetTableId(void *pTable) {
-  assert(pTable);
-  return ((STable*)pTable)->tableId;
-}
-
 STableCfg *tsdbCreateTableCfgFromMsg(SMDCreateTableMsg *pMsg) {
   if (pMsg == NULL) return NULL;
 
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index 39176f339b227922df51a63456b39c9389b449a7..a4e0151f8992753bf4726408c30bdf3910c3da75 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -122,7 +122,7 @@ static void changeQueryHandleForInterpQuery(TsdbQueryHandleT pHandle);
 static void doMergeTwoLevelData(STsdbQueryHandle* pQueryHandle, STableCheckInfo* pCheckInfo, SCompBlock* pBlock,
                                    SArray* sa);
 static int32_t binarySearchForKey(char* pValue, int num, TSKEY key, int order);
-static int tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int maxRowsToRead, TSKEY* skey, TSKEY* ekey,
+static int tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int maxRowsToRead, STimeWindow* win,
                                  STsdbQueryHandle* pQueryHandle);
 
 static void tsdbInitDataBlockLoadInfo(SDataBlockLoadInfo* pBlockLoadInfo) {
@@ -412,8 +412,7 @@ static bool hasMoreDataInCache(STsdbQueryHandle* pHandle) {
   
   int32_t step = ASCENDING_TRAVERSE(pHandle->order)? 1:-1;
   STimeWindow* win = &pHandle->cur.win;
-  pHandle->cur.rows = tsdbReadRowsFromCache(pCheckInfo, pHandle->window.ekey,
-                                    pHandle->outputCapacity, &win->skey, &win->ekey, pHandle);  // todo refactor API
+  pHandle->cur.rows = tsdbReadRowsFromCache(pCheckInfo, pHandle->window.ekey, pHandle->outputCapacity, win, pHandle);
   
   // update the last key value
   pCheckInfo->lastKey = win->ekey + step;
@@ -643,7 +642,7 @@ static void handleDataMergeIfNeeded(STsdbQueryHandle* pQueryHandle, SCompBlock*
       int32_t step = ASCENDING_TRAVERSE(pQueryHandle->order) ? 1 : -1;
 
       cur->rows = tsdbReadRowsFromCache(pCheckInfo, binfo.window.skey - step,
-                                        pQueryHandle->outputCapacity, &cur->win.skey, &cur->win.ekey, pQueryHandle);
+                                        pQueryHandle->outputCapacity, &cur->win, pQueryHandle);
       pQueryHandle->realNumOfRows = cur->rows;
 
       // update the last key value
@@ -1244,7 +1243,6 @@ static int32_t dataBlockOrderCompar(const void* pLeft, const void* pRight, void*
   //    assert(pLeftBlockInfoEx->compBlock->offset != pRightBlockInfoEx->compBlock->offset);
   if (pLeftBlockInfoEx->compBlock->offset == pRightBlockInfoEx->compBlock->offset &&
       pLeftBlockInfoEx->compBlock->last == pRightBlockInfoEx->compBlock->last) {
-    // todo add more information
     tsdbError("error in header file, two block with same offset:%" PRId64, (int64_t)pLeftBlockInfoEx->compBlock->offset);
   }
 
@@ -1701,11 +1699,11 @@ static void changeQueryHandleForInterpQuery(TsdbQueryHandleT pHandle) {
   pQueryHandle->window = (STimeWindow) {info.lastKey, TSKEY_INITIAL_VAL};
 }
 
-static int tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int maxRowsToRead, TSKEY* skey, TSKEY* ekey,
+static int tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int maxRowsToRead, STimeWindow* win,
                                  STsdbQueryHandle* pQueryHandle) {
   int     numOfRows = 0;
   int32_t numOfCols = taosArrayGetSize(pQueryHandle->pColumns);
-  *skey = TSKEY_INITIAL_VAL;
+  win->skey = TSKEY_INITIAL_VAL;
 
   int64_t st = taosGetTimestampUs();
   STsdbMeta* pMeta = tsdbGetMeta(pQueryHandle->pTsdb);
@@ -1725,11 +1723,11 @@ static int tsdbReadRowsFromCache(STableCheckInfo* pCheckInfo, TSKEY maxKey, int
       break;
     }
 
-    if (*skey == INT64_MIN) {
-      *skey = key;
+    if (win->skey == INT64_MIN) {
+      win->skey = key;
     }
 
-    *ekey = key;
+    win->ekey = key;
     copyOneRowFromMem(pQueryHandle, maxRowsToRead, numOfRows, row, pMeta, numOfCols, pTable);
 
     if (++numOfRows >= maxRowsToRead) {
@@ -1978,9 +1976,9 @@ int32_t tableGroupComparFn(const void *p1, const void *p2, const void *param) {
     int32_t type = 0;
     int32_t bytes = 0;
     
-    if (colIndex == TSDB_TBNAME_COLUMN_INDEX) {  // todo refactor extract method , to queryExecutor to generate tags values
-      f1 = (char*) pTable1->name;
-      f2 = (char*) pTable2->name;
+    if (colIndex == TSDB_TBNAME_COLUMN_INDEX) {
+      f1 = (char*) TABLE_NAME(pTable1);
+      f2 = (char*) TABLE_NAME(pTable2);
       type = TSDB_DATA_TYPE_BINARY;
       bytes = tGetTableNameColumnSchema().bytes;
     } else {
@@ -2089,13 +2087,17 @@ bool indexedNodeFilterFp(const void* pNode, void* param) {
   char*  val = NULL;
 
   if (pInfo->colIndex == TSDB_TBNAME_COLUMN_INDEX) {
-    val = (char*) pTable->name;
+    val = (char*) TABLE_NAME(pTable);
   } else {
     val = tdGetKVRowValOfCol(pTable->tagVal, pInfo->sch.colId);
   }
   
-  //todo :the val is possible to be null, so check it out carefully
-  int32_t ret = pInfo->compare(val, pInfo->q);
+  int32_t ret = 0;
+  if (val == NULL) { //the val is possible to be null, so check it out carefully
+    ret = -1; // val is missing in table tags value pairs
+  } else {
+    ret = pInfo->compare(val, pInfo->q);
+  }
 
   switch (pInfo->optr) {
     case TSDB_RELATION_EQUAL: {