diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index d59c9252f3..5ac5ffdd9b 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -3569,11 +3569,18 @@ int32_t blockDataCheck(const SSDataBlock* pDataBlock) {
           } else {
             BLOCK_DATA_CHECK_TRESSA(pCol->varmeta.offset[r] == nextPos);
           }
-          
-          colLen = varDataTLen(pCol->pData + pCol->varmeta.offset[r]);
+
+          char*   pColData = pCol->pData + pCol->varmeta.offset[r];
+          int32_t colSize = 0;
+          if (pCol->info.type == TSDB_DATA_TYPE_JSON) {
+            colLen = getJsonValueLen(pColData);
+          } else {
+            colLen = varDataTLen(pColData);
+          }
+
           BLOCK_DATA_CHECK_TRESSA(colLen >= VARSTR_HEADER_SIZE);
           BLOCK_DATA_CHECK_TRESSA(colLen <= pCol->info.bytes);
-          
+
           if (pCol->reassigned) {
             BLOCK_DATA_CHECK_TRESSA((pCol->varmeta.offset[r] + colLen) <= pCol->varmeta.length);
           } else {
diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index bd72498508..e66ddf5197 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -1606,7 +1606,7 @@ static int32_t translateOutVarchar(SFunctionNode* pFunc, char* pErrBuf, int32_t
       break;
     case FUNCTION_TYPE_BLOCK_DIST:
     case FUNCTION_TYPE_BLOCK_DIST_INFO:
-      bytes = 128;
+      bytes = sizeof(STableBlockDistInfo);
       break;
     case FUNCTION_TYPE_TO_CHAR:
       bytes = 4096;