From 4bc61ad0b292b8e03fe41d71dfe5e86fd41c0208 Mon Sep 17 00:00:00 2001
From: pe-99y <315053752@qq.com>
Date: Mon, 25 Nov 2024 05:18:30 +0000
Subject: [PATCH] fix query hung when nlj child do not support vectorization

---
 src/sql/engine/basic/ob_group_join_buffer_v2.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/sql/engine/basic/ob_group_join_buffer_v2.cpp b/src/sql/engine/basic/ob_group_join_buffer_v2.cpp
index 013e2c05e..751035ccb 100644
--- a/src/sql/engine/basic/ob_group_join_buffer_v2.cpp
+++ b/src/sql/engine/basic/ob_group_join_buffer_v2.cpp
@@ -387,6 +387,8 @@ int ObDriverRowBuffer::get_next_left_batch(int64_t max_rows, const ObBatchRows *
 int ObDriverRowBuffer::get_next_batch_from_store(int64_t max_rows, int64_t &read_rows)
 {
   int ret = OB_SUCCESS;
+  // when disable vectorization, at least read one row
+  max_rows = max_rows > 0 ? max_rows : 1;
   if (left_store_iter_.is_valid() && left_store_iter_.has_next()) {
     if (OB_FAIL(left_store_iter_.get_next_batch(left_->get_spec().output_, *eval_ctx_, max_rows, read_rows))) {
       if (OB_ITER_END != ret) {