initialize table schema from ss information

29 files changed, 297 insertions, 102 deletions

diff --git a/ydb/core/tx/tiering/rule/CMakeLists.txt b/ydb/core/tx/tiering/rule/CMakeLists.txt
index bff4d48a6d..72a76159e5 100644
--- a/ydb/core/tx/tiering/rule/CMakeLists.txt
+++ b/ydb/core/tx/tiering/rule/CMakeLists.txt
@@ -14,8 +14,9 @@ target_compile_options(tx-tiering-rule PRIVATE
 target_link_libraries(tx-tiering-rule PUBLIC
   contrib-libs-cxxsupp
   yutil
-  services-metadata-initializer
   services-metadata-abstract
+  services-metadata-common
+  services-metadata-initializer
   services-bg_tasks-abstract
   core-tx-schemeshard
 )
@@ -25,8 +26,6 @@ target_sources(tx-tiering-rule PRIVATE
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/tiering/rule/initializer.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/tiering/rule/checker.cpp
   ${CMAKE_SOURCE_DIR}/ydb/core/tx/tiering/rule/ss_checker.cpp
-  ${CMAKE_SOURCE_DIR}/ydb/core/tx/tiering/rule/timeout.cpp
-  ${CMAKE_SOURCE_DIR}/ydb/core/tx/tiering/rule/ss_dialog.cpp
 )
 
 add_global_library_for(tx-tiering-rule.global tx-tiering-rule)
@@ -36,8 +35,9 @@ target_compile_options(tx-tiering-rule.global PRIVATE
 target_link_libraries(tx-tiering-rule.global PUBLIC
   contrib-libs-cxxsupp
   yutil
-  services-metadata-initializer
   services-metadata-abstract
+  services-metadata-common
+  services-metadata-initializer
   services-bg_tasks-abstract
   core-tx-schemeshard
 )
diff --git a/ydb/core/tx/tiering/rule/manager.cpp b/ydb/core/tx/tiering/rule/manager.cpp
index 83b7a29e6c..aa16310215 100644
--- a/ydb/core/tx/tiering/rule/manager.cpp
+++ b/ydb/core/tx/tiering/rule/manager.cpp
@@ -30,12 +30,4 @@ NMetadata::NModifications::TOperationParsingResult TTieringRulesManager::DoBuild
     return result;
 }
 
-NMetadata::NModifications::TTableSchema TTieringRulesManager::ConstructActualSchema() const {
-    NMetadata::NModifications::TTableSchema result;
-    result.AddColumn(true, NMetadata::NInternal::TYDBColumn::Bytes(TTieringRule::TDecoder::TieringRuleId))
-        .AddColumn(false, NMetadata::NInternal::TYDBColumn::Bytes(TTieringRule::TDecoder::DefaultColumn))
-        .AddColumn(false, NMetadata::NInternal::TYDBColumn::Bytes(TTieringRule::TDecoder::Description));
-    return result;
-}
-
 }
diff --git a/ydb/core/tx/tiering/rule/manager.h b/ydb/core/tx/tiering/rule/manager.h
index a88cc15b9f..371e931ef0 100644
--- a/ydb/core/tx/tiering/rule/manager.h
+++ b/ydb/core/tx/tiering/rule/manager.h
@@ -13,8 +13,6 @@ protected:
 
     virtual NMetadata::NModifications::TOperationParsingResult DoBuildPatchFromSettings(const NYql::TObjectSettingsImpl& settings,
         const NMetadata::NModifications::IOperationsManager::TModificationContext& /*context*/) const override;
-
-    virtual NMetadata::NModifications::TTableSchema ConstructActualSchema() const override;
 };
 
 }
diff --git a/ydb/core/tx/tiering/rule/ss_checker.h b/ydb/core/tx/tiering/rule/ss_checker.h
index f2932523b4..65a033330d 100644
--- a/ydb/core/tx/tiering/rule/ss_checker.h
+++ b/ydb/core/tx/tiering/rule/ss_checker.h
@@ -1,12 +1,12 @@
 #pragma once
 #include "object.h"
-#include "ss_dialog.h"
 
 #include <ydb/core/base/appdata.h>
 #include <ydb/core/base/tablet_pipecache.h>
 #include <ydb/core/tx/schemeshard/schemeshard.h>
 #include <ydb/core/tx/scheme_cache/scheme_cache.h>
 #include <ydb/core/tx/tx_proxy/proxy.h>
+#include <ydb/services/metadata/common/ss_dialog.h>
 
 namespace NKikimr::NColumnShard::NTiers {
 
@@ -35,9 +35,9 @@ public:
     }
 };
 
-class TSSFetchingActor: public TSSDialogActor {
+class TSSFetchingActor: public NMetadata::NInternal::TSSDialogActor {
 private:
-    using TBase = TSSDialogActor;
+    using TBase = NMetadata::NInternal::TSSDialogActor;
     NSchemeShard::ISSDataProcessor::TPtr Processor;
     ISSFetchingController::TPtr Controller;
     void Handle(NSchemeShard::TEvSchemeShard::TEvProcessingResponse::TPtr& ev);
diff --git a/ydb/core/tx/tiering/rule/timeout.cpp b/ydb/core/tx/tiering/rule/timeout.cpp
deleted file mode 100644
index b1982635cd..0000000000
--- a/ydb/core/tx/tiering/rule/timeout.cpp
+++ /dev/null
@@ -1,5 +0,0 @@
-#include "timeout.h"
-
-namespace NKikimr::NColumnShard::NTiers {
-
-}
diff --git a/ydb/core/tx/tiering/tier/manager.cpp b/ydb/core/tx/tiering/tier/manager.cpp
index 1944e18ec3..3939a18663 100644
--- a/ydb/core/tx/tiering/tier/manager.cpp
+++ b/ydb/core/tx/tiering/tier/manager.cpp
@@ -31,11 +31,4 @@ void TTiersManager::DoPrepareObjectsBeforeModification(std::vector<TTierConfig>&
     TActivationContext::Register(new TTierPreparationActor(std::move(patchedObjects), controller, context));
 }
 
-NMetadata::NModifications::TTableSchema TTiersManager::ConstructActualSchema() const {
-    NMetadata::NModifications::TTableSchema result;
-    result.AddColumn(true, NMetadata::NInternal::TYDBColumn::Bytes(TTierConfig::TDecoder::TierName))
-        .AddColumn(false, NMetadata::NInternal::TYDBColumn::Bytes(TTierConfig::TDecoder::TierConfig));
-    return result;
-}
-
 }
diff --git a/ydb/core/tx/tiering/tier/manager.h b/ydb/core/tx/tiering/tier/manager.h
index 062056613b..32f4481567 100644
--- a/ydb/core/tx/tiering/tier/manager.h
+++ b/ydb/core/tx/tiering/tier/manager.h
@@ -13,8 +13,6 @@ protected:
 
     virtual NMetadata::NModifications::TOperationParsingResult DoBuildPatchFromSettings(const NYql::TObjectSettingsImpl& settings,
         const NMetadata::NModifications::IOperationsManager::TModificationContext& /*context*/) const override;
-
-    virtual NMetadata::NModifications::TTableSchema ConstructActualSchema() const override;
 public:
 };
 
diff --git a/ydb/services/metadata/CMakeLists.txt b/ydb/services/metadata/CMakeLists.txt
index 96609b8fa6..e25aecd950 100644
--- a/ydb/services/metadata/CMakeLists.txt
+++ b/ydb/services/metadata/CMakeLists.txt
@@ -7,6 +7,7 @@
 
 
 add_subdirectory(abstract)
+add_subdirectory(common)
 add_subdirectory(ds_table)
 add_subdirectory(initializer)
 add_subdirectory(manager)
diff --git a/ydb/services/metadata/abstract/common.h b/ydb/services/metadata/abstract/common.h
index 7995a7dad3..864f031295 100644
--- a/ydb/services/metadata/abstract/common.h
+++ b/ydb/services/metadata/abstract/common.h
@@ -13,7 +13,7 @@
 
 namespace NKikimr::NMetadata::NProvider {
 
-enum EEvSubscribe {
+enum EEvents {
     EvRefreshSubscriberData = EventSpaceBegin(TKikimrEvents::ES_METADATA_PROVIDER),
     EvRefresh,
     EvEnrichSnapshotResult,
@@ -28,10 +28,13 @@ enum EEvSubscribe {
     EvAlterObjects,
     EvPrepareManager,
     EvManagerPrepared,
+    EvTimeout,
+    EvTableDescriptionFailed,
+    EvTableDescriptionSuccess,
     EvEnd
 };
 
-static_assert(EEvSubscribe::EvEnd < EventSpaceEnd(TKikimrEvents::ES_METADATA_PROVIDER), "expect EvEnd < EventSpaceEnd(TKikimrEvents::ES_METADATA_PROVIDER)");
+static_assert(EEvents::EvEnd < EventSpaceEnd(TKikimrEvents::ES_METADATA_PROVIDER), "expect EvEnd < EventSpaceEnd(TKikimrEvents::ES_METADATA_PROVIDER)");
 
 class TEvRefreshSubscriberData: public NActors::TEventLocal<TEvRefreshSubscriberData, EvRefreshSubscriberData> {
 private:
diff --git a/ydb/services/metadata/common/CMakeLists.txt b/ydb/services/metadata/common/CMakeLists.txt
new file mode 100644
index 0000000000..49675e7c46
--- /dev/null
+++ b/ydb/services/metadata/common/CMakeLists.txt
@@ -0,0 +1,25 @@
+
+# This file was gererated by the build system used internally in the Yandex monorepo.
+# Only simple modifications are allowed (adding source-files to targets, adding simple properties
+# like target_include_directories). These modifications will be ported to original
+# ya.make files by maintainers. Any complex modifications which can't be ported back to the
+# original buildsystem will not be accepted.
+
+
+
+add_library(services-metadata-common)
+target_compile_options(services-metadata-common PRIVATE
+  -DUSE_CURRENT_UDF_ABI_VERSION
+)
+target_link_libraries(services-metadata-common PUBLIC
+  contrib-libs-cxxsupp
+  yutil
+  services-metadata-initializer
+  services-metadata-abstract
+  services-bg_tasks-abstract
+  core-tx-schemeshard
+)
+target_sources(services-metadata-common PRIVATE
+  ${CMAKE_SOURCE_DIR}/ydb/services/metadata/common/timeout.cpp
+  ${CMAKE_SOURCE_DIR}/ydb/services/metadata/common/ss_dialog.cpp
+)
diff --git a/ydb/core/tx/tiering/rule/ss_dialog.cpp b/ydb/services/metadata/common/ss_dialog.cpp
index ebd79e2641..ebe2851c3e 100644
--- a/ydb/core/tx/tiering/rule/ss_dialog.cpp
+++ b/ydb/services/metadata/common/ss_dialog.cpp
@@ -5,7 +5,7 @@
 #include <ydb/core/protos/services.pb.h>
 #include <ydb/core/tx/scheme_cache/scheme_cache.h>
 
-namespace NKikimr::NColumnShard::NTiers {
+namespace NKikimr::NMetadata::NInternal {
 
 void TSSDialogActor::Handle(TEvPipeCache::TEvDeliveryProblem::TPtr& /*ev*/) {
     OnFail("cannot delivery message to schemeshard");
diff --git a/ydb/core/tx/tiering/rule/ss_dialog.h b/ydb/services/metadata/common/ss_dialog.h
index bb97e1161a..76ee93198f 100644
--- a/ydb/core/tx/tiering/rule/ss_dialog.h
+++ b/ydb/services/metadata/common/ss_dialog.h
@@ -1,12 +1,11 @@
 #pragma once
-
 #include "timeout.h"
 
 #include <ydb/core/base/tablet_pipe.h>
 #include <ydb/core/tx/scheme_cache/scheme_cache.h>
 #include <ydb/core/base/tablet_pipecache.h>
 
-namespace NKikimr::NColumnShard::NTiers {
+namespace NKikimr::NMetadata::NInternal {
 
 class TSSDialogActor: public TTimeoutActor<TSSDialogActor> {
 private:
diff --git a/ydb/services/metadata/common/timeout.cpp b/ydb/services/metadata/common/timeout.cpp
new file mode 100644
index 0000000000..2024c77b6d
--- /dev/null
+++ b/ydb/services/metadata/common/timeout.cpp
@@ -0,0 +1,5 @@
+#include "timeout.h"
+
+namespace NKikimr::NMetadata::NInternal {
+
+}
diff --git a/ydb/core/tx/tiering/rule/timeout.h b/ydb/services/metadata/common/timeout.h
index 437d6fb328..170dda6855 100644
--- a/ydb/core/tx/tiering/rule/timeout.h
+++ b/ydb/services/metadata/common/timeout.h
@@ -1,14 +1,14 @@
 #pragma once
 
 #include <ydb/core/base/appdata.h>
-#include <ydb/core/tx/tiering/common.h>
+#include <ydb/services/metadata/abstract/common.h>
 
 #include <library/cpp/actors/core/actor_bootstrapped.h>
 #include <library/cpp/actors/core/events.h>
 
-namespace NKikimr::NColumnShard::NTiers {
+namespace NKikimr::NMetadata::NInternal {
 
-class TEvTimeout: public NActors::TEventLocal<TEvTimeout, EEvents::EvTimeout> {
+class TEvTimeout: public NActors::TEventLocal<TEvTimeout, NProvider::EEvents::EvTimeout> {
 
 };
 
diff --git a/ydb/services/metadata/ds_table/CMakeLists.txt b/ydb/services/metadata/ds_table/CMakeLists.txt
index 350ba78180..fbb641ff7b 100644
--- a/ydb/services/metadata/ds_table/CMakeLists.txt
+++ b/ydb/services/metadata/ds_table/CMakeLists.txt
@@ -13,6 +13,7 @@ target_link_libraries(services-metadata-ds_table PUBLIC
   yutil
   cpp-actors-core
   ydb-core-base
+  services-metadata-common
   core-grpc_services-local_rpc
   core-grpc_services-base
   ydb-core-grpc_services
@@ -22,6 +23,7 @@ target_link_libraries(services-metadata-ds_table PUBLIC
 target_sources(services-metadata-ds_table PRIVATE
   ${CMAKE_SOURCE_DIR}/ydb/services/metadata/ds_table/accessor_refresh.cpp
   ${CMAKE_SOURCE_DIR}/ydb/services/metadata/ds_table/accessor_subscribe.cpp
+  ${CMAKE_SOURCE_DIR}/ydb/services/metadata/ds_table/scheme_describe.cpp
   ${CMAKE_SOURCE_DIR}/ydb/services/metadata/ds_table/service.cpp
   ${CMAKE_SOURCE_DIR}/ydb/services/metadata/ds_table/config.cpp
 )
diff --git a/ydb/services/metadata/ds_table/accessor_refresh.h b/ydb/services/metadata/ds_table/accessor_refresh.h
index 5aace95ad7..da76f6dd81 100644
--- a/ydb/services/metadata/ds_table/accessor_refresh.h
+++ b/ydb/services/metadata/ds_table/accessor_refresh.h
@@ -9,11 +9,11 @@ namespace NKikimr::NMetadata::NProvider {
 
 class TDSAccessorRefresher;
 
-class TEvRefresh: public NActors::TEventLocal<TEvRefresh, EEvSubscribe::EvRefresh> {
+class TEvRefresh: public NActors::TEventLocal<TEvRefresh, EEvents::EvRefresh> {
 public:
 };
 
-class TEvYQLResponse: public NActors::TEventLocal<TEvYQLResponse, EEvSubscribe::EvYQLResponse> {
+class TEvYQLResponse: public NActors::TEventLocal<TEvYQLResponse, EEvents::EvYQLResponse> {
 private:
     YDB_READONLY_DEF(NRequest::TDialogYQLRequest::TResponse, Response);
 public:
@@ -24,7 +24,7 @@ public:
     }
 };
 
-class TEvEnrichSnapshotResult: public NActors::TEventLocal<TEvEnrichSnapshotResult, EEvSubscribe::EvEnrichSnapshotResult> {
+class TEvEnrichSnapshotResult: public NActors::TEventLocal<TEvEnrichSnapshotResult, EEvents::EvEnrichSnapshotResult> {
 private:
     YDB_READONLY_DEF(NFetcher::ISnapshot::TPtr, EnrichedSnapshot);
 public:
@@ -34,7 +34,7 @@ public:
     }
 };
 
-class TEvEnrichSnapshotProblem: public NActors::TEventLocal<TEvEnrichSnapshotProblem, EEvSubscribe::EvEnrichSnapshotProblem> {
+class TEvEnrichSnapshotProblem: public NActors::TEventLocal<TEvEnrichSnapshotProblem, EEvents::EvEnrichSnapshotProblem> {
 private:
     YDB_READONLY_DEF(TString, ErrorText);
 public:
diff --git a/ydb/services/metadata/ds_table/accessor_subscribe.h b/ydb/services/metadata/ds_table/accessor_subscribe.h
index 292f6e58f6..809d543631 100644
--- a/ydb/services/metadata/ds_table/accessor_subscribe.h
+++ b/ydb/services/metadata/ds_table/accessor_subscribe.h
@@ -5,7 +5,7 @@ namespace NKikimr::NMetadata::NProvider {
 
 class TDSAccessorNotifier;
 
-class TEvAsk: public NActors::TEventLocal<TEvAsk, EEvSubscribe::EvAskLocal> {
+class TEvAsk: public NActors::TEventLocal<TEvAsk, EEvents::EvAskLocal> {
 private:
     YDB_READONLY_DEF(TActorId, RequesterId);
 public:
@@ -15,7 +15,7 @@ public:
     }
 };
 
-class TEvSubscribe: public NActors::TEventLocal<TEvSubscribe, EEvSubscribe::EvSubscribeLocal> {
+class TEvSubscribe: public NActors::TEventLocal<TEvSubscribe, EEvents::EvSubscribeLocal> {
 private:
     YDB_READONLY_DEF(TActorId, SubscriberId);
 public:
@@ -25,7 +25,7 @@ public:
     }
 };
 
-class TEvUnsubscribe: public NActors::TEventLocal<TEvUnsubscribe, EEvSubscribe::EvUnsubscribeLocal> {
+class TEvUnsubscribe: public NActors::TEventLocal<TEvUnsubscribe, EEvents::EvUnsubscribeLocal> {
 private:
     YDB_READONLY_DEF(TActorId, SubscriberId);
 public:
diff --git a/ydb/services/metadata/ds_table/scheme_describe.cpp b/ydb/services/metadata/ds_table/scheme_describe.cpp
new file mode 100644
index 0000000000..baed2ec3e7
--- /dev/null
+++ b/ydb/services/metadata/ds_table/scheme_describe.cpp
@@ -0,0 +1,62 @@
+#include "scheme_describe.h"
+
+#include <ydb/core/tx/scheme_cache/scheme_cache.h>
+#include <ydb/core/tx/schemeshard/schemeshard.h>
+#include <ydb/core/protos/services.pb.h>
+#include <ydb/core/ydb_convert/ydb_convert.h>
+#include <ydb/core/ydb_convert/table_description.h>
+
+namespace NKikimr::NMetadata::NProvider {
+
+void TSchemeDescriptionActor::Handle(NSchemeShard::TEvSchemeShard::TEvDescribeSchemeResult::TPtr& ev) {
+    auto g = PassAwayGuard();
+    const auto& record = ev->Get()->GetRecord();
+    const auto status = record.GetStatus();
+    if (record.HasReason()) {
+        auto issue = NYql::TIssue(record.GetReason());
+        Controller->OnDescriptionFailed(issue.ToString(), RequestId);
+        return;
+    }
+    Ydb::Table::DescribeTableResult describeTableResult;
+    if (status != NKikimrScheme::StatusSuccess) {
+        Controller->OnDescriptionFailed(::ToString(status), RequestId);
+        return;
+    }
+    const auto& pathDescription = record.GetPathDescription();
+    Ydb::Scheme::Entry* selfEntry = describeTableResult.mutable_self();
+    selfEntry->set_name(pathDescription.GetSelf().GetName());
+    selfEntry->set_type(static_cast<Ydb::Scheme::Entry::Type>(pathDescription.GetSelf().GetPathType()));
+    ConvertDirectoryEntry(pathDescription.GetSelf(), selfEntry, true);
+
+    if (pathDescription.HasColumnTableDescription()) {
+        const auto& tableDescription = pathDescription.GetColumnTableDescription();
+        FillColumnDescription(describeTableResult, tableDescription);
+    } else {
+        const auto& tableDescription = pathDescription.GetTable();
+        NKikimrMiniKQL::TType splitKeyType;
+
+        try {
+            FillColumnDescription(describeTableResult, splitKeyType, tableDescription);
+        } catch (const std::exception& ex) {
+            Controller->OnDescriptionFailed("Unable to fill column description: " + CurrentExceptionMessage(), RequestId);
+            return;
+        }
+
+        describeTableResult.mutable_primary_key()->CopyFrom(tableDescription.GetKeyColumnNames());
+    }
+    Controller->OnDescriptionSuccess(std::move(describeTableResult), RequestId);
+}
+
+void TSchemeDescriptionActor::Execute() {
+    auto event = std::make_unique<NSchemeShard::TEvSchemeShard::TEvDescribeScheme>(Path);
+    event->Record.MutableOptions()->SetReturnPartitioningInfo(false);
+    event->Record.MutableOptions()->SetReturnPartitionConfig(false);
+    event->Record.MutableOptions()->SetReturnChildren(false);
+    Send(SchemeShardPipe, new TEvPipeCache::TEvForward(event.release(), SchemeShardId, false));
+}
+
+void TSchemeDescriptionActor::OnFail(const TString& errorMessage) {
+    Controller->OnDescriptionFailed(errorMessage, RequestId);
+}
+
+}
diff --git a/ydb/services/metadata/ds_table/scheme_describe.h b/ydb/services/metadata/ds_table/scheme_describe.h
new file mode 100644
index 0000000000..41f0b76cff
--- /dev/null
+++ b/ydb/services/metadata/ds_table/scheme_describe.h
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <ydb/core/tx/schemeshard/schemeshard.h>
+#include <ydb/services/metadata/common/ss_dialog.h>
+
+namespace NKikimr::NMetadata::NProvider {
+
+class ISchemeDescribeController {
+public:
+    using TPtr = std::shared_ptr<ISchemeDescribeController>;
+    virtual ~ISchemeDescribeController() = default;
+    virtual void OnDescriptionFailed(const TString& errorMessage, const TString& requestId) const = 0;
+    virtual void OnDescriptionSuccess(Ydb::Table::DescribeTableResult&& result, const TString& requestId) const = 0;
+};
+
+class TSchemeDescriptionActor: public NInternal::TSSDialogActor {
+private:
+    using TBase = NInternal::TSSDialogActor;
+    ISchemeDescribeController::TPtr Controller;
+    TString Path;
+    TString RequestId;
+    void Handle(NSchemeShard::TEvSchemeShard::TEvDescribeSchemeResult::TPtr& ev);
+protected:
+    virtual void OnBootstrap() override {
+        Become(&TSchemeDescriptionActor::StateMain);
+        TBase::OnBootstrap();
+    }
+    virtual void OnFail(const TString& errorMessage) override;
+    virtual void Execute() override;
+public:
+    static constexpr NKikimrServices::TActivity::EType ActorActivityType();
+    STFUNC(StateMain) {
+        switch (ev->GetTypeRewrite()) {
+            hFunc(NSchemeShard::TEvSchemeShard::TEvDescribeSchemeResult, Handle);
+            default:
+                TBase::StateMain(ev, ctx);
+        }
+    }
+    TSchemeDescriptionActor(ISchemeDescribeController::TPtr controller, const TString& reqId, const TString& path, const TDuration livetime)
+        : TBase(livetime)
+        , Controller(controller)
+        , Path(path)
+        , RequestId(reqId)
+    {
+
+    }
+};
+
+}
diff --git a/ydb/services/metadata/ds_table/service.cpp b/ydb/services/metadata/ds_table/service.cpp
index ce4af34759..b4d863e854 100644
--- a/ydb/services/metadata/ds_table/service.cpp
+++ b/ydb/services/metadata/ds_table/service.cpp
@@ -37,18 +37,17 @@ void TService::PrepareManagers(std::vector<IClassBehaviour::TPtr> managers, TAut
 void TService::Handle(TEvPrepareManager::TPtr& ev) {
     auto it = RegisteredManagers.find(ev->Get()->GetManager()->GetTypeId());
     if (it != RegisteredManagers.end()) {
-        Send(ev->Sender, new TEvManagerPrepared(ev->Get()->GetManager()));
+        Send(ev->Sender, new TEvManagerPrepared(it->second));
     } else {
         auto m = ev->Get()->GetManager();
         PrepareManagers({ m }, ev->ReleaseBase(), ev->Sender);
     }
 }
 
-void TService::Handle(NInitializer::TEvInitializationFinished::TPtr& ev) {
-    const TString& initId = ev->Get()->GetInitializationId();
-
+void TService::InitializationFinished(const TString& initId) {
     auto it = ManagersInRegistration.find(initId);
     Y_VERIFY(it != ManagersInRegistration.end());
+
     RegisteredManagers.emplace(initId, it->second);
     ManagersInRegistration.erase(it);
 
@@ -80,6 +79,32 @@ void TService::Handle(NInitializer::TEvInitializationFinished::TPtr& ev) {
     }
 }
 
+void TService::Handle(TEvTableDescriptionSuccess::TPtr& ev) {
+    const TString& initId = ev->Get()->GetRequestId();
+    auto it = ManagersInRegistration.find(initId);
+    Y_VERIFY(it != ManagersInRegistration.end());
+    it->second->GetOperationsManager()->SetActualSchema(ev->Get()->GetSchema());
+    InitializationFinished(initId);
+}
+
+void TService::Handle(TEvTableDescriptionFailed::TPtr& ev) {
+    const TString& initId = ev->Get()->GetRequestId();
+    ALS_INFO(NKikimrServices::METADATA_PROVIDER) << "metadata service cannot receive table description for " << initId << Endl;
+    Schedule(TDuration::Seconds(1), new NInitializer::TEvInitializationFinished(initId));
+}
+
+void TService::Handle(NInitializer::TEvInitializationFinished::TPtr& ev) {
+    const TString& initId = ev->Get()->GetInitializationId();
+
+    auto it = ManagersInRegistration.find(initId);
+    Y_VERIFY(it != ManagersInRegistration.end());
+    if (it->second->GetOperationsManager()) {
+        Register(new TSchemeDescriptionActor(InternalController, initId, it->second->GetStorageTablePath(), TDuration::Seconds(5)));
+    } else {
+        InitializationFinished(initId);
+    }
+}
+
 void TService::Handle(TEvSubscribeExternal::TPtr& ev) {
     const TActorId senderId = ev->Sender;
     ProcessEventWithFetcher(ev, [this, senderId](const TActorId& actorId) {
@@ -97,6 +122,7 @@ void TService::Handle(TEvAskSnapshot::TPtr& ev) {
 void TService::Handle(TEvObjectsOperation::TPtr& ev) {
     auto it = RegisteredManagers.find(ev->Get()->GetCommand()->GetManager()->GetTypeId());
     if (it != RegisteredManagers.end()) {
+        ev->Get()->GetCommand()->SetManager(it->second);
         ev->Get()->GetCommand()->Execute();
     } else {
         auto m = ev->Get()->GetCommand()->GetManager();
@@ -134,4 +160,12 @@ void TServiceInternalController::InitializationFinished(const TString& id) const
     ActorId.Send(ActorId, new NInitializer::TEvInitializationFinished(id));
 }
 
+void TServiceInternalController::OnDescriptionFailed(const TString& errorMessage, const TString& requestId) const {
+    ActorId.Send(ActorId, new TEvTableDescriptionFailed(errorMessage, requestId));
+}
+
+void TServiceInternalController::OnDescriptionSuccess(Ydb::Table::DescribeTableResult&& result, const TString& requestId) const {
+    ActorId.Send(ActorId, new TEvTableDescriptionSuccess(std::move(result), requestId));
+}
+
 }
diff --git a/ydb/services/metadata/ds_table/service.h b/ydb/services/metadata/ds_table/service.h
index 11907f97b4..4552173cec 100644
--- a/ydb/services/metadata/ds_table/service.h
+++ b/ydb/services/metadata/ds_table/service.h
@@ -1,6 +1,7 @@
 #pragma once
 #include "accessor_subscribe.h"
 #include "config.h"
+#include "scheme_describe.h"
 
 #include <ydb/services/metadata/service.h>
 #include <ydb/services/metadata/initializer/common.h>
@@ -8,12 +9,41 @@
 #include <ydb/services/metadata/initializer/manager.h>
 #include <ydb/services/metadata/initializer/snapshot.h>
 #include <ydb/services/metadata/initializer/fetcher.h>
+#include <ydb/services/metadata/manager/abstract.h>
 
 #include <library/cpp/actors/core/hfunc.h>
 
 namespace NKikimr::NMetadata::NProvider {
 
-class TServiceInternalController: public NInitializer::IInitializerOutput {
+class TEvTableDescriptionFailed: public TEventLocal<TEvTableDescriptionFailed, EEvents::EvTableDescriptionFailed> {
+private:
+    YDB_READONLY_DEF(TString, ErrorMessage);
+    YDB_READONLY_DEF(TString, RequestId);
+public:
+    explicit TEvTableDescriptionFailed(const TString& errorMessage, const TString& reqId)
+        : ErrorMessage(errorMessage)
+        , RequestId(reqId) {
+
+    }
+};
+
+class TEvTableDescriptionSuccess: public TEventLocal<TEvTableDescriptionSuccess, EEvents::EvTableDescriptionSuccess> {
+private:
+    YDB_READONLY_DEF(TString, RequestId);
+    YDB_READONLY_DEF(Ydb::Table::DescribeTableResult, Description);
+public:
+    TEvTableDescriptionSuccess(Ydb::Table::DescribeTableResult&& description, const TString& reqId)
+        : RequestId(reqId)
+        , Description(std::move(description))
+    {
+    }
+
+    NModifications::TTableSchema GetSchema() const {
+        return NModifications::TTableSchema(Description);
+    }
+};
+
+class TServiceInternalController: public NInitializer::IInitializerOutput, public ISchemeDescribeController {
 private:
     const NActors::TActorIdentity ActorId;
 public:
@@ -24,6 +54,9 @@ public:
     }
 
     virtual void InitializationFinished(const TString& id) const override;
+
+    virtual void OnDescriptionFailed(const TString& errorMessage, const TString& requestId) const override;
+    virtual void OnDescriptionSuccess(Ydb::Table::DescribeTableResult&& result, const TString& requestId) const override;
 };
 
 class TManagersId {
@@ -112,7 +145,12 @@ private:
     void Handle(TEvSubscribeExternal::TPtr& ev);
     void Handle(TEvUnsubscribeExternal::TPtr& ev);
     void Handle(TEvObjectsOperation::TPtr& ev);
+    void Handle(TEvTableDescriptionSuccess::TPtr& ev);
+    void Handle(TEvTableDescriptionFailed::TPtr& ev);
+
     void PrepareManagers(std::vector<IClassBehaviour::TPtr> manager, TAutoPtr<IEventBase> ev, const NActors::TActorId& sender);
+    void InitializationFinished(const TString& initId);
+    void RequestTableDescription(const TString& path) const;
 
     template <class TEventPtr, class TAction>
     void ProcessEventWithFetcher(TEventPtr& ev, TAction action) {
@@ -146,6 +184,10 @@ public:
             hFunc(TEvPrepareManager, Handle);
             hFunc(TEvSubscribeExternal, Handle);
             hFunc(TEvUnsubscribeExternal, Handle);
+
+            hFunc(TEvTableDescriptionSuccess, Handle);
+            hFunc(TEvTableDescriptionFailed, Handle);
+            
             hFunc(NInitializer::TEvInitializationFinished, Handle);
             default:
                 Y_VERIFY(false);
diff --git a/ydb/services/metadata/initializer/manager.cpp b/ydb/services/metadata/initializer/manager.cpp
index 0fcdbc0e7d..55859c8b2f 100644
--- a/ydb/services/metadata/initializer/manager.cpp
+++ b/ydb/services/metadata/initializer/manager.cpp
@@ -17,12 +17,4 @@ NModifications::TOperationParsingResult TManager::DoBuildPatchFromSettings(
     return result;
 }
 
-NModifications::TTableSchema TManager::ConstructActualSchema() const {
-    NModifications::TTableSchema result;
-    result.AddColumn(true, NInternal::TYDBColumn::Bytes(TDBInitialization::TDecoder::ComponentId))
-        .AddColumn(true, NInternal::TYDBColumn::Bytes(TDBInitialization::TDecoder::ModificationId))
-        .AddColumn(false, NInternal::TYDBColumn::UInt32(TDBInitialization::TDecoder::Instant));
-    return result;
-}
-
 }
diff --git a/ydb/services/metadata/initializer/manager.h b/ydb/services/metadata/initializer/manager.h
index 5e8403d81c..7c004d33ab 100644
--- a/ydb/services/metadata/initializer/manager.h
+++ b/ydb/services/metadata/initializer/manager.h
@@ -20,7 +20,6 @@ protected:
     virtual NModifications::TOperationParsingResult DoBuildPatchFromSettings(const NYql::TObjectSettingsImpl& /*settings*/,
         const TModificationContext& /*context*/) const override;
 
-    virtual NModifications::TTableSchema ConstructActualSchema() const override;
 public:
 };
 
diff --git a/ydb/services/metadata/manager/abstract.cpp b/ydb/services/metadata/manager/abstract.cpp
index 5af027f1a4..021fe5dc14 100644
--- a/ydb/services/metadata/manager/abstract.cpp
+++ b/ydb/services/metadata/manager/abstract.cpp
@@ -2,4 +2,37 @@
 
 namespace NKikimr::NMetadata::NModifications {
 
+TTableSchema::TTableSchema(const Ydb::Table::DescribeTableResult& description) {
+    std::map<TString, Ydb::Column> columns;
+    for (auto&& i : description.columns()) {
+        Ydb::Column column;
+        column.set_name(i.name());
+        if (i.type().has_optional_type()) {
+            *column.mutable_type() = i.type().optional_type().item();
+        } else {
+            *column.mutable_type() = i.type();
+        }
+        columns.emplace(i.name(), std::move(column));
+    }
+    for (auto&& i : description.primary_key()) {
+        auto it = columns.find(i);
+        Y_VERIFY(it != columns.end());
+        AddColumn(true, it->second);
+        columns.erase(it);
+    }
+    for (auto&& i : columns) {
+        AddColumn(false, i.second);
+    }
+}
+
+NKikimr::NMetadata::NModifications::TTableSchema& TTableSchema::AddColumn(const bool primary, const Ydb::Column& info) noexcept {
+    Columns.emplace_back(primary, info);
+    YDBColumns.emplace_back(info);
+    if (primary) {
+        PKColumns.emplace_back(info);
+        PKColumnIds.emplace_back(info.name());
+    }
+    return *this;
+}
+
 }
diff --git a/ydb/services/metadata/manager/abstract.h b/ydb/services/metadata/manager/abstract.h
index 558392c726..38a66b39f6 100644
--- a/ydb/services/metadata/manager/abstract.h
+++ b/ydb/services/metadata/manager/abstract.h
@@ -114,16 +114,10 @@ private:
     YDB_READONLY_DEF(std::vector<Ydb::Column>, YDBColumns);
     YDB_READONLY_DEF(std::vector<Ydb::Column>, PKColumns);
     YDB_READONLY_DEF(std::vector<TString>, PKColumnIds);
+
+    TTableSchema& AddColumn(const bool primary, const Ydb::Column& info) noexcept;
 public:
-    TTableSchema& AddColumn(const bool primary, const Ydb::Column& info) noexcept {
-        Columns.emplace_back(primary, info);
-        YDBColumns.emplace_back(info);
-        if (primary) {
-            PKColumns.emplace_back(info);
-            PKColumnIds.emplace_back(info.name());
-        }
-        return *this;
-    }
+    TTableSchema(const Ydb::Table::DescribeTableResult& description);
 };
 
 class IOperationsManager {
@@ -145,9 +139,7 @@ public:
         TModificationContext() = default;
     };
 private:
-    mutable std::optional<TTableSchema> ActualSchema;
-protected:
-    virtual TTableSchema ConstructActualSchema() const = 0;
+    YDB_ACCESSOR_DEF(std::optional<TTableSchema>, ActualSchema);
 protected:
     virtual NThreading::TFuture<TObjectOperatorResult> DoCreateObject(const NYql::TCreateObjectSettings& settings, const ui32 nodeId,
         IClassBehaviour::TPtr manager, const TModificationContext& context) const = 0;
@@ -172,10 +164,9 @@ public:
         IClassBehaviour::TPtr manager, const TModificationContext& context) const {
         return DoDropObject(settings, nodeId, manager, context);
     }
+
     const TTableSchema& GetSchema() const {
-        if (!ActualSchema) {
-            ActualSchema = ConstructActualSchema();
-        }
+        Y_VERIFY(!!ActualSchema);
         return *ActualSchema;
     }
 };
@@ -206,7 +197,7 @@ public:
 class IAlterCommand {
 private:
     YDB_READONLY_DEF(std::vector<NInternal::TTableRecord>, Records);
-    YDB_READONLY_DEF(IClassBehaviour::TPtr, Manager);
+    YDB_ACCESSOR_DEF(IClassBehaviour::TPtr, Manager);
     YDB_READONLY_DEF(IAlterController::TPtr, Controller);
 protected:
     mutable IOperationsManager::TModificationContext Context;
diff --git a/ydb/services/metadata/manager/common.h b/ydb/services/metadata/manager/common.h
index 55e2dd5ba7..c2dcbc3ea6 100644
--- a/ydb/services/metadata/manager/common.h
+++ b/ydb/services/metadata/manager/common.h
@@ -25,7 +25,6 @@ public:
     virtual void AlterFinished() = 0;
 
 };
-}
 
 enum EEvents {
     EvRestoreFinished = EventSpaceBegin(TKikimrEvents::ES_METADATA_MANAGER),
@@ -38,6 +37,7 @@ enum EEvents {
     EvAlterPreparationProblem,
     EvEnd
 };
-
 static_assert(EEvents::EvEnd < EventSpaceEnd(TKikimrEvents::ES_METADATA_MANAGER), "expect EvEnd < EventSpaceEnd(TKikimrEvents::ES_METADATA_MANAGER)");
 }
+
+}
diff --git a/ydb/services/metadata/secret/manager.cpp b/ydb/services/metadata/secret/manager.cpp
index 1bbe015e26..c1f60a41d0 100644
--- a/ydb/services/metadata/secret/manager.cpp
+++ b/ydb/services/metadata/secret/manager.cpp
@@ -44,14 +44,6 @@ NModifications::TOperationParsingResult TAccessManager::DoBuildPatchFromSettings
     return result;
 }
 
-NModifications::TTableSchema TAccessManager::ConstructActualSchema() const {
-    NModifications::TTableSchema result;
-    result.AddColumn(true, NInternal::TYDBColumn::Bytes(TAccess::TDecoder::OwnerUserId))
-        .AddColumn(true, NInternal::TYDBColumn::Bytes(TAccess::TDecoder::SecretId))
-        .AddColumn(true, NInternal::TYDBColumn::Bytes(TAccess::TDecoder::AccessSID));
-    return result;
-}
-
 NModifications::TOperationParsingResult TSecretManager::DoBuildPatchFromSettings(const NYql::TObjectSettingsImpl& settings, const NModifications::IOperationsManager::TModificationContext& context) const {
     NInternal::TTableRecord result;
     if (!context.GetUserToken()) {
@@ -103,12 +95,4 @@ void TSecretManager::DoPrepareObjectsBeforeModification(std::vector<TSecret>&& p
     TActivationContext::Register(new TSecretPreparationActor(std::move(patchedObjects), controller, context));
 }
 
-NModifications::TTableSchema TSecretManager::ConstructActualSchema() const {
-    NModifications::TTableSchema result;
-    result.AddColumn(true, NInternal::TYDBColumn::Bytes(TSecret::TDecoder::OwnerUserId))
-        .AddColumn(true, NInternal::TYDBColumn::Bytes(TSecret::TDecoder::SecretId))
-        .AddColumn(false, NInternal::TYDBColumn::Bytes(TSecret::TDecoder::Value));
-    return result;
-}
-
 }
diff --git a/ydb/services/metadata/secret/manager.h b/ydb/services/metadata/secret/manager.h
index 1a135ea866..dd4817ae7e 100644
--- a/ydb/services/metadata/secret/manager.h
+++ b/ydb/services/metadata/secret/manager.h
@@ -13,7 +13,6 @@ protected:
 
     virtual NModifications::TOperationParsingResult DoBuildPatchFromSettings(
         const NYql::TObjectSettingsImpl& settings, const NModifications::IOperationsManager::TModificationContext& context) const override;
-    virtual NModifications::TTableSchema ConstructActualSchema() const override;
 
 public:
 };
@@ -26,7 +25,6 @@ protected:
 
     virtual NModifications::TOperationParsingResult DoBuildPatchFromSettings(const NYql::TObjectSettingsImpl& settings,
         const NModifications::IOperationsManager::TModificationContext& context) const override;
-    virtual NModifications::TTableSchema ConstructActualSchema() const override;
 public:
 };
 
diff --git a/ydb/services/metadata/service.h b/ydb/services/metadata/service.h
index f4c1ea5679..a144249101 100644
--- a/ydb/services/metadata/service.h
+++ b/ydb/services/metadata/service.h
@@ -4,7 +4,7 @@
 
 namespace NKikimr::NMetadata::NProvider {
 
-class TEvObjectsOperation: public NActors::TEventLocal<TEvObjectsOperation, EEvSubscribe::EvAlterObjects> {
+class TEvObjectsOperation: public NActors::TEventLocal<TEvObjectsOperation, EEvents::EvAlterObjects> {
 private:
     YDB_READONLY_DEF(NModifications::IAlterCommand::TPtr, Command);
 public:
@@ -14,7 +14,7 @@ public:
     }
 };
 
-class TEvPrepareManager: public NActors::TEventLocal<TEvPrepareManager, EEvSubscribe::EvPrepareManager> {
+class TEvPrepareManager: public NActors::TEventLocal<TEvPrepareManager, EEvents::EvPrepareManager> {
 private:
     YDB_READONLY_DEF(IClassBehaviour::TPtr, Manager);
 public:
@@ -24,7 +24,7 @@ public:
     }
 };
 
-class TEvManagerPrepared: public NActors::TEventLocal<TEvManagerPrepared, EEvSubscribe::EvManagerPrepared> {
+class TEvManagerPrepared: public NActors::TEventLocal<TEvManagerPrepared, EEvents::EvManagerPrepared> {
 private:
     YDB_READONLY_DEF(IClassBehaviour::TPtr, Manager);
 public:
@@ -34,7 +34,7 @@ public:
     }
 };
 
-class TEvAskSnapshot: public NActors::TEventLocal<TEvAskSnapshot, EEvSubscribe::EvAskExternal> {
+class TEvAskSnapshot: public NActors::TEventLocal<TEvAskSnapshot, EEvents::EvAskExternal> {
 private:
     YDB_READONLY_DEF(NFetcher::ISnapshotsFetcher::TPtr, Fetcher);
 public:
@@ -44,7 +44,7 @@ public:
     }
 };
 
-class TEvSubscribeExternal: public NActors::TEventLocal<TEvSubscribeExternal, EEvSubscribe::EvSubscribeExternal> {
+class TEvSubscribeExternal: public NActors::TEventLocal<TEvSubscribeExternal, EEvents::EvSubscribeExternal> {
 private:
     YDB_READONLY_DEF(NFetcher::ISnapshotsFetcher::TPtr, Fetcher);
 public:
@@ -55,7 +55,7 @@ public:
     }
 };
 
-class TEvUnsubscribeExternal: public NActors::TEventLocal<TEvUnsubscribeExternal, EEvSubscribe::EvUnsubscribeExternal> {
+class TEvUnsubscribeExternal: public NActors::TEventLocal<TEvUnsubscribeExternal, EEvents::EvUnsubscribeExternal> {
 private:
     YDB_READONLY_DEF(NFetcher::ISnapshotsFetcher::TPtr, Fetcher);
 public: