diff --git a/src/query/inc/queryLog.h b/src/query/inc/queryLog.h
index 26544ab0f9152a9c0282893f20956e99a1987afe..5c48c43c45fdb5cffdcc01901f1ede4a3b98d240 100644
--- a/src/query/inc/queryLog.h
+++ b/src/query/inc/queryLog.h
@@ -30,6 +30,7 @@ extern uint32_t qDebugFlag;
 #define qInfo(...)  do { if (qDebugFlag & DEBUG_INFO)  { taosPrintLog("QRY ", 255, __VA_ARGS__); }}        while(0)
 #define qDebug(...) do { if (qDebugFlag & DEBUG_DEBUG) { taosPrintLog("QRY ", qDebugFlag, __VA_ARGS__); }} while(0)
 #define qTrace(...) do { if (qDebugFlag & DEBUG_TRACE) { taosPrintLog("QRY ", qDebugFlag, __VA_ARGS__); }} while(0)
+#define qDump(a, l) do { if (qDebugFlag & DEBUG_DUMP)  { taosDumpData((unsigned char *)a, l); }} while(0)
 
 #ifdef __cplusplus
 }
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 38ba6b54008bc91c83b6a3be9b74ad287b52604c..b8dbf8726f5394ff99e8e7279b3f3e9b93e9da4e 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -7164,10 +7164,19 @@ static int32_t doDumpQueryResult(SQInfo *pQInfo, char *data) {
       if (fseek(f, 0, SEEK_SET) >= 0) {
         size_t sz = fread(data, 1, s, f);
         if(sz < s) {  // todo handle error
+          qError("fread(f:%p,%d) failed, rsize:%" PRId64 ", expect size:%" PRId64, f, fileno(f), sz, s);
           assert(0);
         }
       } else {
         UNUSED(s);
+        qError("fseek(f:%p,%d) failed, error:%s", f, fileno(f), strerror(errno));
+        assert(0);
+      }
+
+      if (s <= (sizeof(STSBufFileHeader) + sizeof(STSGroupBlockInfo) + 6 * sizeof(int32_t))) {
+        qDump(data, s);
+        
+        assert(0);
       }
 
       fclose(f);