diff --git a/source/dnode/vnode/src/inc/tsdb.h b/source/dnode/vnode/src/inc/tsdb.h
index 7ad16e5583..90fdd60188 100644
--- a/source/dnode/vnode/src/inc/tsdb.h
+++ b/source/dnode/vnode/src/inc/tsdb.h
@@ -359,7 +359,7 @@ struct SMapData {
 typedef struct {
   int16_t cid;
   int8_t  type;
-  int8_t  flag;
+  int8_t  flag;  // HAS_NONE|HAS_NULL|HAS_VALUE
   int64_t offset;
   int64_t size;
 } SBlockCol;
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index b6065a82bd..73df7ae80f 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -58,7 +58,7 @@ _err:
   return code;
 }
 
-static int32_t tMapDataGetOffset(SMapData *pMapData, int32_t idx) {
+static FORCE_INLINE int32_t tMapDataGetOffset(SMapData *pMapData, int32_t idx) {
   switch (pMapData->flag) {
     case TSDB_OFFSET_I8:
       return ((int8_t *)pMapData->pOfst)[idx];
@@ -130,7 +130,7 @@ int32_t tPutMapData(uint8_t *p, SMapData *pMapData) {
     n += tPutU8(p ? p + n : p, TSDB_OFFSET_I8);
     if (p) {
       for (int32_t iItem = 0; iItem < pMapData->nItem; iItem++) {
-        n += tPutI8(p + n, (int8_t)(((int32_t *)pMapData->pData)[iItem]));
+        n += tPutI8(p + n, (int8_t)tMapDataGetOffset(pMapData, iItem));
       }
     } else {
       n = n + sizeof(int8_t) * pMapData->nItem;
@@ -139,7 +139,7 @@ int32_t tPutMapData(uint8_t *p, SMapData *pMapData) {
     n += tPutU8(p ? p + n : p, TSDB_OFFSET_I16);
     if (p) {
       for (int32_t iItem = 0; iItem < pMapData->nItem; iItem++) {
-        n += tPutI16(p + n, (int16_t)(((int32_t *)pMapData->pData)[iItem]));
+        n += tPutI16(p + n, (int16_t)tMapDataGetOffset(pMapData, iItem));
       }
     } else {
       n = n + sizeof(int16_t) * pMapData->nItem;
@@ -148,7 +148,7 @@ int32_t tPutMapData(uint8_t *p, SMapData *pMapData) {
     n += tPutU8(p ? p + n : p, TSDB_OFFSET_I32);
     if (p) {
       for (int32_t iItem = 0; iItem < pMapData->nItem; iItem++) {
-        n += tPutI32(p + n, (int32_t)(((int32_t *)pMapData->pData)[iItem]));
+        n += tPutI32(p + n, tMapDataGetOffset(pMapData, iItem));
       }
     } else {
       n = n + sizeof(int32_t) * pMapData->nItem;
@@ -331,7 +331,7 @@ void tBlockReset(SBlock *pBlock) {
   pBlock->last = -1;
   pBlock->hasDup = 0;
   pBlock->cmprAlg = -1;
-  for (int8_t iSubBlock = 0; iSubBlock < pBlock->nSubBlock; iSubBlock++) {
+  for (int8_t iSubBlock = 0; iSubBlock < TSDB_MAX_SUBBLOCKS; iSubBlock++) {
     pBlock->aSubBlock[iSubBlock].offset = -1;
     pBlock->aSubBlock[iSubBlock].ksize = -1;
     pBlock->aSubBlock[iSubBlock].bsize = -1;