diff --git a/src/tsdb/inc/tsdbMain.h b/src/tsdb/inc/tsdbMain.h
index d856650b0ee245bdd132e4e3fb22e25dfb8aa40a..4cd2f459177945d0e8b428d8075f6c83808868f5 100644
--- a/src/tsdb/inc/tsdbMain.h
+++ b/src/tsdb/inc/tsdbMain.h
@@ -195,7 +195,6 @@ typedef struct {
 typedef struct {
   uint32_t len;
   uint32_t offset;
-  // uint32_t padding;
   uint32_t hasLast : 2;
   uint32_t numOfBlocks : 30;
   uint64_t uid;
@@ -224,7 +223,7 @@ typedef struct {
 
 typedef struct {
   int16_t colId;
-  int16_t len;
+  int32_t len;
   int32_t type : 8;
   int32_t offset : 24;
   int64_t sum;
diff --git a/src/tsdb/src/tsdbRWHelper.c b/src/tsdb/src/tsdbRWHelper.c
index 9e87a1f587971be02f66151725d7f1a19455184b..0fc94c07a873a00b34c4802fb81aa81d046212bb 100644
--- a/src/tsdb/src/tsdbRWHelper.c
+++ b/src/tsdb/src/tsdbRWHelper.c
@@ -703,6 +703,7 @@ static int tsdbWriteBlockToFile(SRWHelper *pHelper, SFile *pFile, SDataCols *pDa
     }
 
     // Add checksum
+    ASSERT(pCompCol->len > 0);
     pCompCol->len += sizeof(TSCKSUM);
     taosCalcChecksumAppend(0, (uint8_t *)tptr, pCompCol->len);