diff --git a/src/tsdb/inc/tsdbMain.h b/src/tsdb/inc/tsdbMain.h
index 7a6735291bea625806c627ba6902d852d04f0884..5045c341d6161c140a1182d521618a1a6623dc44 100644
--- a/src/tsdb/inc/tsdbMain.h
+++ b/src/tsdb/inc/tsdbMain.h
@@ -447,13 +447,11 @@ typedef struct {
 
 int  tsdbInitReadHelper(SRWHelper *pHelper, STsdbRepo *pRepo);
 int  tsdbInitWriteHelper(SRWHelper *pHelper, STsdbRepo *pRepo);
-// int  tsdbInitHelper(SRWHelper *pHelper, SHelperCfg *pCfg);
 void tsdbDestroyHelper(SRWHelper *pHelper);
 void tsdbResetHelper(SRWHelper *pHelper);
 
 // --------- For set operations
 int tsdbSetAndOpenHelperFile(SRWHelper *pHelper, SFileGroup *pGroup);
-// void tsdbSetHelperTable(SRWHelper *pHelper, SHelperTable *pHelperTable, STSchema *pSchema);
 void tsdbSetHelperTable(SRWHelper *pHelper, STable *pTable, STsdbRepo *pRepo);
 int  tsdbCloseHelperFile(SRWHelper *pHelper, bool hasError);
 
diff --git a/src/tsdb/src/tsdbRWHelper.c b/src/tsdb/src/tsdbRWHelper.c
index 888ee069ae40a0e98e4dbe0990aef359fc2a515c..d1ee5113fd3a8b94900087904663daa7b0ff2f4b 100644
--- a/src/tsdb/src/tsdbRWHelper.c
+++ b/src/tsdb/src/tsdbRWHelper.c
@@ -131,6 +131,11 @@ static int tsdbInitHelper(SRWHelper *pHelper, STsdbRepo *pRepo, tsdb_rw_helper_t
   // Init block part
   if (tsdbInitHelperBlock(pHelper) < 0) goto _err;
 
+  pHelper->blockBuffer =
+      tmalloc(sizeof(SCompData) + (sizeof(SCompCol) + sizeof(TSCKSUM) + COMP_OVERFLOW_BYTES) * pHelper->config.maxCols +
+              pHelper->config.maxRowSize * pHelper->config.maxRowsPerFileBlock + sizeof(TSCKSUM));
+  if (pHelper->blockBuffer == NULL) goto _err;
+
   return 0;
 
 _err:
@@ -149,6 +154,8 @@ int tsdbInitWriteHelper(SRWHelper *pHelper, STsdbRepo *pRepo) {
 
 void tsdbDestroyHelper(SRWHelper *pHelper) {
   if (pHelper) {
+    tzfree(pHelper->blockBuffer);
+    tzfree(pHelper->compBuffer);
     tsdbDestroyHelperFile(pHelper);
     tsdbDestroyHelperTable(pHelper);
     tsdbDestroyHelperBlock(pHelper);
@@ -563,6 +570,8 @@ static int tsdbCheckAndDecodeColumnData(SDataCol *pDataCol, char *content, int32
     void *pStart = NULL;
     if (pDataCol->type == TSDB_DATA_TYPE_BINARY || pDataCol->type == TSDB_DATA_TYPE_NCHAR) {
       pStart = (char *)(pDataCol->pData) + sizeof(int32_t) * maxPoints;
+    } else {
+      pStart = pDataCol->pData;
     }
     // TODO: get rid of INT32_MAX here
     pDataCol->len = (*(tDataTypeDesc[pDataCol->type].decompFunc))(content, len - sizeof(TSCKSUM), numOfPoints, pStart,
@@ -597,8 +606,7 @@ static int tsdbCheckAndDecodeColumnData(SDataCol *pDataCol, char *content, int32
 static int tsdbLoadBlockDataImpl(SRWHelper *pHelper, SCompBlock *pCompBlock, SDataCols *pDataCols) {
   ASSERT(pCompBlock->numOfSubBlocks <= 1);
 
-  pHelper->blockBuffer = trealloc(pHelper->blockBuffer, pCompBlock->len);
-  if (pHelper->blockBuffer == NULL) return -1;
+  ASSERT(tsizeof(pHelper->blockBuffer) >= pCompBlock->len);
 
   SCompData *pCompData = (SCompData *)pHelper->blockBuffer;
 
@@ -627,9 +635,13 @@ static int tsdbLoadBlockDataImpl(SRWHelper *pHelper, SCompBlock *pCompBlock, SDa
     SCompCol *pCompCol = &(pCompData->cols[ccol]);
 
     if (pCompCol->colId == pDataCol->colId) {
+      if (pCompBlock->algorithm == TWO_STAGE_COMP) {
+        pHelper->compBuffer = trealloc(pHelper->compBuffer, pCompCol->len + COMP_OVERFLOW_BYTES);
+        if (pHelper->compBuffer == NULL) goto _err;
+      }
       if (tsdbCheckAndDecodeColumnData(pDataCol, (char *)pCompData + tsize + pCompCol->offset, pCompCol->len,
-                                       pCompBlock->algorithm, pCompBlock->numOfPoints, pDataCols->maxPoints, pHelper->compBuffer,
-                                       tsizeof(pHelper->compBuffer)) < 0)
+                                       pCompBlock->algorithm, pCompBlock->numOfPoints, pDataCols->maxPoints,
+                                       pHelper->compBuffer, tsizeof(pHelper->compBuffer)) < 0)
         goto _err;
       dcol++;
       ccol++;
@@ -731,6 +743,11 @@ static int tsdbWriteBlockToFile(SRWHelper *pHelper, SFile *pFile, SDataCols *pDa
 
     // TODO: compresee the data
     if (pHelper->config.compress) {
+      if (pHelper->config.compress == TWO_STAGE_COMP) {
+        pHelper->compBuffer = trealloc(pHelper->compBuffer, tlen + COMP_OVERFLOW_BYTES);
+        if (pHelper->compBuffer == NULL) goto _err;
+      }
+
       pCompCol->len = (*(tDataTypeDesc[pDataCol->type].compFunc))(
           (char *)pStart, tlen, rowsToWrite, tptr, tsizeof(pHelper->blockBuffer) - lsize, pHelper->config.compress,
           pHelper->compBuffer, tsizeof(pHelper->compBuffer));