Implement auto transaction

Author: UgnineSirdis

ydb/core/kqp/session_actor/kqp_query_state.cpp

@@ -306,4 +306,21 @@ bool TKqpQueryState::HasErrors(const NSchemeCache::TSchemeCacheNavigate& respons
     return true;
 }
 
+bool TKqpQueryState::HasImpliedAutostartTransactions() const {
+    if (!HasTxControl()
+        && (RequestEv->GetAction() == NKikimrKqp::QUERY_ACTION_EXECUTE
+            || RequestEv->GetAction() == NKikimrKqp::QUERY_ACTION_EXECUTE_PREPARED)
+        && (RequestEv->GetType() == NKikimrKqp::QUERY_TYPE_SQL_GENERIC_QUERY
+            || RequestEv->GetType() == NKikimrKqp::QUERY_TYPE_SQL_GENERIC_SCRIPT
+            || RequestEv->GetType() == NKikimrKqp::QUERY_TYPE_SQL_GENERIC_CONCURRENT_QUERY))
+    {
+        for (const auto& transactionPtr : PreparedQuery->GetTransactions()) {
+            if (transactionPtr->GetType() == NKqpProto::TKqpPhyTx::TYPE_GENERIC) { // data transaction
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
 }

ydb/core/kqp/session_actor/kqp_query_state.h

@@ -362,6 +362,8 @@ class TKqpQueryState : public TNonCopyable {
         return RequestEv->HasTxControl();
     }
 
+    bool HasImpliedAutostartTransactions() const;
+
     const ::Ydb::Table::TransactionControl& GetTxControl() const {
         return RequestEv->GetTxControl();
     }

ydb/core/kqp/session_actor/kqp_session_actor.cpp

@@ -636,9 +636,21 @@ class TKqpSessionActor : public TActorBootstrapped<TKqpSessionActor> {
         Counters->ReportBeginTransaction(Settings.DbCounters, Transactions.EvictedTx, Transactions.Size(), Transactions.ToBeAbortedSize());
     }
 
+    static const Ydb::Table::TransactionControl& GetAutoTransactionControl() {
+        auto create = []() -> Ydb::Table::TransactionControl {
+            Ydb::Table::TransactionControl control;
+            control.mutable_begin_tx()->mutable_serializable_read_write();
+            control.set_commit_tx(true);
+            return control;
+        };
+        static const Ydb::Table::TransactionControl control = create();
+        return control;
+    }
+
     bool PrepareQueryTransaction() {
-        if (QueryState->HasTxControl()) {
-            const auto& txControl = QueryState->GetTxControl();
+        bool autoTransaction = false;
+        if (QueryState->HasTxControl() || (autoTransaction = QueryState->HasImpliedAutostartTransactions())) {
+            const auto& txControl = autoTransaction ? GetAutoTransactionControl() : QueryState->GetTxControl();
 
             QueryState->Commit = txControl.commit_tx();
             switch (txControl.tx_selector_case()) {
@@ -941,7 +953,7 @@ class TKqpSessionActor : public TActorBootstrapped<TKqpSessionActor> {
                 case NKqpProto::TKqpPhyTx::TYPE_SCHEME:
                     YQL_ENSURE(tx->StagesSize() == 0);
 
-                    if (QueryState->TxCtx->EffectiveIsolationLevel != NKikimrKqp::ISOLATION_LEVEL_UNDEFINED) {
+                    if (QueryState->HasTxControl() && QueryState->TxCtx->EffectiveIsolationLevel != NKikimrKqp::ISOLATION_LEVEL_UNDEFINED) {
                         ReplyQueryError(Ydb::StatusIds::PRECONDITION_FAILED,
                             "Scheme operations cannot be executed inside transaction");
                         return true;

ydb/core/kqp/ut/service/kqp_qs_queries_ut.cpp

@@ -1534,7 +1534,7 @@ Y_UNIT_TEST_SUITE(KqpQueryService) {
             UPSERT INTO KeyValue (Key, Value) VALUES (3, "Three");
             SELECT * FROM KeyValue;
         )", TTxControl::NoTx()).ExtractValueSync();
-        UNIT_ASSERT_VALUES_EQUAL_C(result.GetStatus(), EStatus::PRECONDITION_FAILED, result.GetIssues().ToString());
+        UNIT_ASSERT_VALUES_EQUAL_C(result.GetStatus(), EStatus::SUCCESS, result.GetIssues().ToString());
     }
 
     Y_UNIT_TEST(Tcl) {