From cd6e2d650cf37ae1e1cb22a153eebcf4d1887660 Mon Sep 17 00:00:00 2001
From: Handora <qcdsr970209@gmail.com>
Date: Wed, 19 Jul 2023 08:42:14 +0000
Subject: [PATCH] [BUG] only check sequence set with the first one

---
 src/storage/memtable/mvcc/ob_mvcc_define.h | 7 ++++++-
 src/storage/memtable/mvcc/ob_mvcc_row.cpp  | 1 +
 src/storage/memtable/ob_memtable.cpp       | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/storage/memtable/mvcc/ob_mvcc_define.h b/src/storage/memtable/mvcc/ob_mvcc_define.h
index fac97b49a5..a90e7101ee 100644
--- a/src/storage/memtable/mvcc/ob_mvcc_define.h
+++ b/src/storage/memtable/mvcc/ob_mvcc_define.h
@@ -117,11 +117,14 @@ struct ObMvccWriteResult {
   // tx_node_ is the node used for insert, whether it is inserted is decided by
   // has_insert()
   ObMvccTransNode *tx_node_;
+  // is_checked_ is used to tell lock_rows_on_forzen_stores whether sequence_set_violation has finished its check
+  bool is_checked_;
 
   TO_STRING_KV(K_(can_insert),
                K_(need_insert),
                K_(is_new_locked),
                K_(lock_state),
+               K_(is_checked),
                KPC_(tx_node));
 
   ObMvccWriteResult()
@@ -129,7 +132,8 @@ struct ObMvccWriteResult {
     need_insert_(false),
     is_new_locked_(false),
     lock_state_(),
-    tx_node_(NULL) {}
+    tx_node_(NULL),
+    is_checked_(false) {}
 
   // has_insert indicates whether the insert is succeed
   // It is decided by both can_insert_ and need_insert_
@@ -142,6 +146,7 @@ struct ObMvccWriteResult {
     is_new_locked_ = false;
     lock_state_.reset();
     tx_node_ = NULL;
+    is_checked_ = false;
   }
 };
 
diff --git a/src/storage/memtable/mvcc/ob_mvcc_row.cpp b/src/storage/memtable/mvcc/ob_mvcc_row.cpp
index 0c25af9010..e2337abfaf 100644
--- a/src/storage/memtable/mvcc/ob_mvcc_row.cpp
+++ b/src/storage/memtable/mvcc/ob_mvcc_row.cpp
@@ -914,6 +914,7 @@ int ObMvccRow::mvcc_write_(ObIMemtableCtx &ctx,
                                                                    list_head_->get_dml_flag(),
                                                                    list_head_->get_seq_no()))) {
         TRANS_LOG(WARN, "check sequence set violation failed", K(ret), KPC(this));
+      } else if (nullptr != list_head_ && FALSE_IT(res.is_checked_ = true)) {
       } else if (OB_SUCC(check_double_insert_(snapshot_version,
                                               writer_node,
                                               list_head_))) {
diff --git a/src/storage/memtable/ob_memtable.cpp b/src/storage/memtable/ob_memtable.cpp
index 5ea347bb61..83ab0583b5 100755
--- a/src/storage/memtable/ob_memtable.cpp
+++ b/src/storage/memtable/ob_memtable.cpp
@@ -1205,6 +1205,7 @@ int ObMemtable::lock_row_on_frozen_stores_(
         // We need check whether the same row is operated by same txn
         // concurrently to prevent undesirable resuly.
         if (res.has_insert() &&     // we only need check when the node is exactly inserted
+            !res.is_checked_ &&     // we only need check when the active memtable check is missed
             OB_FAIL(concurrent_control::check_sequence_set_violation(ctx.mvcc_acc_ctx_.write_flag_,
                                                                      reader_seq_no,
                                                                      my_tx_id,