From f1bf21617534c893e66ebace4e84eddd1432fa82 Mon Sep 17 00:00:00 2001
From: Nikita Vasilev <ns-vasilev@ydb.tech>
Date: Tue, 12 Nov 2024 12:22:10 +0300
Subject: [PATCH] EvWrite: add mvcc snapshot (#11474)

---
 ydb/core/kqp/common/kqp_tx.cpp                  |  4 ++++
 ydb/core/kqp/executer_actor/kqp_executer_impl.h |  4 ++++
 ydb/core/kqp/runtime/kqp_write_actor.cpp        | 12 ++++++++++++
 ydb/core/protos/kqp.proto                       |  1 +
 4 files changed, 21 insertions(+)

diff --git a/ydb/core/kqp/common/kqp_tx.cpp b/ydb/core/kqp/common/kqp_tx.cpp
index e2758eff6273..f7a07ee8d169 100644
--- a/ydb/core/kqp/common/kqp_tx.cpp
+++ b/ydb/core/kqp/common/kqp_tx.cpp
@@ -169,6 +169,10 @@ bool NeedSnapshot(const TKqpTransactionContext& txCtx, const NYql::TKikimrConfig
     if (!commitTx)
         return true;
 
+    if (HasOlapTableWriteInTx(physicalQuery) || HasOlapTableReadInTx(physicalQuery)) {
+        return true;
+    }
+
     size_t readPhases = 0;
     bool hasEffects = false;
     bool hasSourceRead = false;
diff --git a/ydb/core/kqp/executer_actor/kqp_executer_impl.h b/ydb/core/kqp/executer_actor/kqp_executer_impl.h
index 90d2813e0473..29e118432b6f 100644
--- a/ydb/core/kqp/executer_actor/kqp_executer_impl.h
+++ b/ydb/core/kqp/executer_actor/kqp_executer_impl.h
@@ -952,6 +952,10 @@ class TKqpExecuterBase : public TActorBootstrapped<TDerived> {
             if (!settings.GetInconsistentTx() && !settings.GetIsOlap()) {
                 ActorIdToProto(BufferActorId, settings.MutableBufferActorId());
             }
+            if (GetSnapshot().IsValid() && settings.GetIsOlap()) {
+                settings.MutableMvccSnapshot()->SetStep(GetSnapshot().Step);
+                settings.MutableMvccSnapshot()->SetTxId(GetSnapshot().TxId);
+            }
             output.SinkSettings.ConstructInPlace();
             output.SinkSettings->PackFrom(settings);
         } else {
diff --git a/ydb/core/kqp/runtime/kqp_write_actor.cpp b/ydb/core/kqp/runtime/kqp_write_actor.cpp
index 65bbffdf93c0..067333d29d15 100644
--- a/ydb/core/kqp/runtime/kqp_write_actor.cpp
+++ b/ydb/core/kqp/runtime/kqp_write_actor.cpp
@@ -170,12 +170,14 @@ class TKqpTableWriteActor : public TActorBootstrapped<TKqpTableWriteActor> {
         const bool inconsistentTx,
         const NMiniKQL::TTypeEnvironment& typeEnv,
         std::shared_ptr<NKikimr::NMiniKQL::TScopedAlloc> alloc,
+        const std::optional<NKikimrDataEvents::TMvccSnapshot>& mvccSnapshot,
         const IKqpTransactionManagerPtr& txManager,
         const TActorId sessionActorId,
         TIntrusivePtr<TKqpCounters> counters,
         NWilson::TTraceId traceId)
         : TypeEnv(typeEnv)
         , Alloc(alloc)
+        , MvccSnapshot(mvccSnapshot)
         , TableId(tableId)
         , TablePath(tablePath)
         , LockTxId(lockTxId)
@@ -812,6 +814,9 @@ class TKqpTableWriteActor : public TActorBootstrapped<TKqpTableWriteActor> {
             FillEvWritePrepare(evWrite.get(), shardId, *TxId, TxManager);
         } else if (!InconsistentTx) {
             evWrite->SetLockId(LockTxId, LockNodeId);
+            if (MvccSnapshot) {
+                *evWrite->Record.MutableMvccSnapshot() = *MvccSnapshot;
+            }
         }
 
         const auto serializationResult = ShardedWriteController->SerializeMessageToPayload(shardId, *evWrite);
@@ -953,6 +958,8 @@ class TKqpTableWriteActor : public TActorBootstrapped<TKqpTableWriteActor> {
     const NMiniKQL::TTypeEnvironment& TypeEnv;
     std::shared_ptr<NKikimr::NMiniKQL::TScopedAlloc> Alloc;
 
+    std::optional<NKikimrDataEvents::TMvccSnapshot> MvccSnapshot;
+
     const TTableId TableId;
     const TString TablePath;
 
@@ -1018,6 +1025,9 @@ class TKqpDirectWriteActor : public TActorBootstrapped<TKqpDirectWriteActor>, pu
             Settings.GetInconsistentTx(),
             TypeEnv,
             Alloc,
+            Settings.GetIsOlap()
+                ? std::optional<NKikimrDataEvents::TMvccSnapshot>{Settings.GetMvccSnapshot()}
+                : std::optional<NKikimrDataEvents::TMvccSnapshot>{},
             nullptr,
             TActorId{},
             Counters,
@@ -1205,6 +1215,7 @@ struct TTransactionSettings {
     ui64 LockTxId = 0;
     ui64 LockNodeId = 0;
     bool InconsistentTx = false;
+    NKikimrDataEvents::TMvccSnapshot MvccSnapshot;
 };
 
 struct TWriteSettings {
@@ -1333,6 +1344,7 @@ class TKqpBufferWriteActor :public TActorBootstrapped<TKqpBufferWriteActor>, pub
                     InconsistentTx,
                     TypeEnv,
                     Alloc,
+                    std::nullopt,
                     TxManager,
                     SessionActorId,
                     Counters,
diff --git a/ydb/core/protos/kqp.proto b/ydb/core/protos/kqp.proto
index b487df72e037..fb46e899f70c 100644
--- a/ydb/core/protos/kqp.proto
+++ b/ydb/core/protos/kqp.proto
@@ -719,6 +719,7 @@ message TKqpTableSinkSettings {
     optional NActorsProto.TActorId BufferActorId = 10;
     optional int64 Priority = 11;
     optional bool IsOlap = 12;
+    optional NKikimrDataEvents.TMvccSnapshot MvccSnapshot = 13;
 }
 
 message TKqpStreamLookupSettings {