diff --git a/src/common/inc/tdataformat.h b/src/common/inc/tdataformat.h
index 706fdeff987ac5fa58ad71b85a2d85c8f8f7586e..1d3319e61dfd2fafda7474cd5f8c30e60bc8b34f 100644
--- a/src/common/inc/tdataformat.h
+++ b/src/common/inc/tdataformat.h
@@ -87,6 +87,22 @@ int       tdGetSchemaEncodeSize(STSchema *pSchema);
 void *    tdEncodeSchema(void *dst, STSchema *pSchema);
 STSchema *tdDecodeSchema(void **psrc);
 
+static FORCE_INLINE int comparColId(const void *key1, const void *key2) {
+  if (*(int16_t *)key1 > ((STColumn *)key2)->colId) {
+    return 1;
+  } else if (*(int16_t *)key1 < ((STColumn *)key2)->colId) {
+    return -1;
+  } else {
+    return 0;
+  }
+}
+
+static FORCE_INLINE STColumn *tdGetColOfID(STSchema *pSchema, int16_t colId) {
+  void *ptr = bsearch(&colId, (void *)pSchema->columns, schemaNCols(pSchema), sizeof(STColumn), comparColId);
+  if (ptr == NULL) return NULL;
+  return (STColumn *)ptr;
+}
+
 // ----------------- Data row structure
 
 /* A data row, the format is like below:
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index 32ad30598b979af7b86606fe3693825db33076fb..f057dcb96e27209ca6a471487fbb845178a2cd35 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -250,29 +250,24 @@ STSchema * tsdbGetTableTagSchema(STsdbMeta *pMeta, STable *pTable) {
 int32_t tsdbGetTableTagVal(TsdbRepoT* repo, STableId* id, int32_t colId, int16_t* type, int16_t* bytes, char** val) {
   STsdbMeta* pMeta = tsdbGetMeta(repo);
   STable* pTable = tsdbGetTableByUid(pMeta, id->uid);
+
+  STSchema *pSchema = tsdbGetTableTagSchema(pMeta, pTable);
+  STColumn *pCol = tdGetColOfID(pSchema, colId);
+  if (pCol == NULL) {
+    return -1; // No matched tag volumn
+  }
   
-  *val = tdQueryTagByID(pTable->tagVal, colId, type);
+  *val = tdGetKVRowValOfCol(pTable->tagVal, colId);
+  *type = pCol->type;
   
   if (*val != NULL) {
-    switch(*type) {
-      case TSDB_DATA_TYPE_BINARY:
-      case TSDB_DATA_TYPE_NCHAR:  *bytes = varDataLen(*val); break;
-      case TSDB_DATA_TYPE_NULL:   *bytes = 0; break;
-      default:
-        *bytes = tDataTypeDesc[*type].nSize;break;
+    if (IS_VAR_DATA_TYPE(*type)) {
+      *bytes = varDataLen(*val);
+    } else {
+      *bytes = TYPE_BYTES[*type];
     }
   }
   
-  if (pCol == NULL) {
-    return -1;  // No matched tags. Maybe the modification of tags has not been done yet.
-  }
-  
-  char* d = tdGetKVRowValOfCol(pTable->tagVal, pCol->colId);
-  //ASSERT((int8_t)tagtype == pCol->type)
-  *val = d;
-  *type  = pCol->type;
-  *bytes = pCol->bytes;
-  
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/src/tsdb/src/tsdbRWHelper.c b/src/tsdb/src/tsdbRWHelper.c
index 8c7f8309ec9c60933d2de419668f7d81b50271f6..5bdf37c81e39453acaef6eb340803f0468d2ca59 100644
--- a/src/tsdb/src/tsdbRWHelper.c
+++ b/src/tsdb/src/tsdbRWHelper.c
@@ -453,7 +453,7 @@ int tsdbWriteCompIdx(SRWHelper *pHelper) {
         pHelper->pBuffer = trealloc(pHelper->pBuffer, tsizeof(pHelper->pBuffer)*2);
       }
       buf = POINTER_SHIFT(pHelper->pBuffer, drift);
-      buf = taosEncodeVariant32(buf, i);
+      buf = taosEncodeVariantU32(buf, i);
       buf = tsdbEncodeSCompIdx(buf, pCompIdx);
     }
   }