diff --git a/source/dnode/vnode/src/tsdb/tsdbMergeTree.c b/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
index 160ff2e13c..2288e8bbce 100644
--- a/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
+++ b/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
@@ -903,6 +903,7 @@ int32_t tLDataIterNextRow(SLDataIter *pIter, const char *idStr, bool* hasNext) {
   pIter->rInfo.row = tsdbRowFromBlockData(pBlockData, pIter->iRow);
 
 _exit:
+  tsdbError("failed to exec stt-file nextIter, lino:%d, code:%s, %s", lino, tstrerror(code), idStr);
   *hasNext = (code == TSDB_CODE_SUCCESS) && (pIter->pSttBlk != NULL) && (pBlockData != NULL);
   return code;
 }