diff --git a/src/vnode/common/data/inc/data.h b/src/vnode/common/data/inc/data.h
deleted file mode 100644
index 376837502560e8671735aa7d343cef98d9921d20..0000000000000000000000000000000000000000
--- a/src/vnode/common/data/inc/data.h
+++ /dev/null
@@ -1,28 +0,0 @@
-#if !defined(_TD_DATA_H_)
-#define _TD_DATA_H_
-
-#include <stdint.h>
-
-#include "schema.h"
-
-/* The row data should in the form of
- */
-
-// ---- Row data interface
-typedef struct {
-  int32_t numOfRows;
-  char *  data;
-} SRData;
-
-// ---- Column data interface
-typedef struct {
-  int32_t numOfPoints;
-  char *  data;
-} SCData;
-
-typedef struct {
-  int32_t  numOfCols;
-  SCData **pData;
-} SCDataBlock;
-
-#endif  // _TD_DATA_H_
diff --git a/src/vnode/common/datastructure/inc/dlist.h b/src/vnode/common/datastructure/inc/dlist.h
deleted file mode 100644
index 81a3b32ab022ee7e9c937e3981316c2fcb1ed205..0000000000000000000000000000000000000000
--- a/src/vnode/common/datastructure/inc/dlist.h
+++ /dev/null
@@ -1,29 +0,0 @@
-// A doubly linked list
-#if !defined(_TD_DLIST_H_)
-#define _TD_DLIST_H_
-
-#include <stdint.h>
-
-typedef struct {
-  SListNode *prev;
-  SListNode *next;
-  void *     data;
-} SListNode;
-
-// Doubly linked list
-typedef struct {
-    SListNode *head;
-    SListNode *tail;
-    int32_t length;
-} SDList;
-
-// ----- Set operation
-#define TD_GET_DLIST_LENGTH(pDList) (((SDList *)pDList)->length)
-#define TD_GET_DLIST_HEAD(pDList) (((SDList *)pDList)->head)
-#define TD_GET_DLIST_TAIL(pDList) (((SDList *)pDList)->tail)
-
-#define TD_GET_DLIST_NEXT_NODE(pDNode) (((SListNode *)pDNode)->next)
-#define TD_GET_DLIST_PREV_NODE(pDNode) (((SListNode *)pDNode)->prev)
-#define TD_GET_DLIST_NODE_DATA(pDNode) (((SListNode *)pDNode)->data)
-
-#endif  // _TD_DLIST_H_
diff --git a/src/vnode/common/inc/dataformat.h b/src/vnode/common/inc/dataformat.h
new file mode 100644
index 0000000000000000000000000000000000000000..3db70c956963248c40473e17b66da6fe5c46a9b9
--- /dev/null
+++ b/src/vnode/common/inc/dataformat.h
@@ -0,0 +1,66 @@
+#if !defined(_TD_DATA_FORMAT_H_)
+#define _TD_DATA_FORMAT_H_
+
+#include <stdint.h>
+
+#include "type.h"
+#include "schema.h"
+
+// ----------------- Data row structure
+
+/* A data row, the format of it is like below:
+ * +---------+---------------------------------+
+ * | int32_t |                                 |
+ * +---------+---------------------------------+
+ * |   len   |               data              |
+ * +---------+---------------------------------+
+ */
+typedef char* SDataRow;
+
+/* Data rows definition, the format of it is like below:
+ * +---------+---------+-----------------------+--------+-----------------------+
+ * | int32_t | int32_t |                       |        |                       |
+ * +---------+---------+-----------------------+--------+-----------------------+
+ * |   len   |  nrows  |        SDataRow       |  ....  |        SDataRow       |
+ * +---------+---------+-----------------------+--------+-----------------------+
+ */
+typedef char * SDataRows;
+
+/* Data column definition
+ * +---------+---------+-----------------------+
+ * | int32_t | int32_t |                       |
+ * +---------+---------+-----------------------+
+ * |   len   | npoints |          data         |
+ * +---------+---------+-----------------------+
+ */
+typedef char * SDataCol;
+
+/* Data columns definition
+ * +---------+---------+-----------------------+--------+-----------------------+
+ * | int32_t | int32_t |                       |        |                       |
+ * +---------+---------+-----------------------+--------+-----------------------+
+ * |   len   | npoints |        SDataCol       |  ....  |        SDataCol       |
+ * +---------+---------+-----------------------+--------+-----------------------+
+ */
+typedef char * SDataCols;
+
+// ----------------- Data column structure
+
+// ---- operation on SDataRow;
+#define TD_DATAROW_LEN(pDataRow) (*(int32_t *)(pDataRow))
+#define TD_DATAROW_DATA(pDataRow) ((pDataRow) + sizeof(int32_t))
+
+// ---- operation on SDataRows
+#define TD_DATAROWS_LEN(pDataRows) (*(int32_t *)(pDataRows))
+#define TD_DATAROWS_ROWS(pDataRows) (*(int32_t *)(pDataRows + sizeof(int32_t)))
+#define TD_NEXT_DATAROW(pDataRow)  ((pDataRow) + TD_DATAROW_LEN(pDataRow))
+
+// ---- operation on SDataCol
+#define TD_DATACOL_LEN(pDataCol) (*(int32_t *)(pDataCol))
+#define TD_DATACOL_NPOINTS(pDataCol) (*(int32_t *)(pDataCol + sizeof(int32_t)))
+
+// ---- operation on SDataCols
+#define TD_DATACOLS_LEN(pDataCols) (*(int32_t *)(pDataCols))
+#define TD_DATACOLS_NPOINTS(pDataCols) (*(int32_t *)(pDataCols + sizeof(int32_t)))
+
+#endif // _TD_DATA_FORMAT_H_
diff --git a/src/vnode/common/catalog/inc/schema.h b/src/vnode/common/inc/schema.h
similarity index 100%
rename from src/vnode/common/catalog/inc/schema.h
rename to src/vnode/common/inc/schema.h
diff --git a/src/vnode/common/catalog/inc/type.h b/src/vnode/common/inc/type.h
similarity index 93%
rename from src/vnode/common/catalog/inc/type.h
rename to src/vnode/common/inc/type.h
index 69aee2a5de6dc73f476cb465977d2e90f6341102..c36d7fd43aecc1ec18d12f1bcd43ba3e20ece05f 100644
--- a/src/vnode/common/catalog/inc/type.h
+++ b/src/vnode/common/inc/type.h
@@ -4,7 +4,7 @@
 #include <stdint.h>
 
 typedef enum : uint8_t {
-    TD_DATATYPE_INVLD = 0,
+    TD_DATATYPE_INVLD = 0, // invalid data type
     TD_DATATYPE_BOOL,
     TD_DATATYPE_TINYINT,
     TD_DATATYPE_SMALLINT,
diff --git a/src/vnode/common/src/dataformat.c b/src/vnode/common/src/dataformat.c
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/src/vnode/tsdb/inc/tsdbCache.h b/src/vnode/tsdb/inc/tsdbCache.h
index 791d1c7d78568cb18efbef006d5fd6813d6058f2..b9de8551bcb3f5254674f1abd32e2acb7c59c5ce 100644
--- a/src/vnode/tsdb/inc/tsdbCache.h
+++ b/src/vnode/tsdb/inc/tsdbCache.h
@@ -23,6 +23,7 @@ typedef struct {
 
 // Use a doublely linked list to implement this
 typedef struct STSDBCache {
+  // Number of blocks the cache is allocated
   int32_t numOfBlocks;
   SDList *cacheList;
   void *  current;
@@ -32,7 +33,7 @@ typedef struct STSDBCache {
 // ---- Operation on STSDBCacheBlock
 #define TSDB_CACHE_BLOCK_DATA(pBlock) ((pBlock)->pData)
 #define TSDB_CACHE_AVAIL_SPACE(pBlock) ((char *)((pBlock)->pTableInfo) - ((pBlock)->pData))
-#define TSDB_TABLE_KEY_RANGE_AT_CACHE(pBlock, tableId) ((pBlock)->pTableInfo)[tableId]
+#define TSDB_TABLE_INFO_OF_CACHE(pBlock, tableId) ((pBlock)->pTableInfo)[tableId]
 #define TSDB_NEXT_CACHE_BLOCK(pBlock) ((pBlock)->next)
 #define TSDB_PREV_CACHE_BLOCK(pBlock) ((pBlock)->prev)