optimize memory footprint of CS schemas

ydb/core/formats/arrow/process_columns.cpp

@@ -207,24 +207,23 @@ NKikimr::TConclusion<std::shared_ptr<arrow::Table>> TColumnOperator::Reorder(
     return ReorderImpl(incoming, columnNames);
 }
 namespace {
-template <class TDataContainer, class TSchemaImpl>
-TConclusion<TSchemaSubset> BuildSequentialSubsetImpl(const std::shared_ptr<TDataContainer>& srcBatch,
-    const std::shared_ptr<TSchemaImpl>& dstSchema, const TColumnOperator::ECheckFieldTypesPolicy checkFieldTypesPolicy) {
+template <class TDataContainer>
+TConclusion<TSchemaSubset> BuildSequentialSubsetImpl(const std::shared_ptr<TDataContainer>& srcBatch, const TSchemaLiteView& dstSchema,
+    const TColumnOperator::ECheckFieldTypesPolicy checkFieldTypesPolicy) {
     AFL_VERIFY(srcBatch);
-    AFL_VERIFY(dstSchema);
-    if (dstSchema->num_fields() < srcBatch->schema()->num_fields()) {
+    if (dstSchema.num_fields() < srcBatch->schema()->num_fields()) {
         AFL_ERROR(NKikimrServices::ARROW_HELPER)("event", "incorrect columns set: destination must been wider than source")(
-            "source", srcBatch->schema()->ToString())("destination", dstSchema->ToString());
+            "source", srcBatch->schema()->ToString())("destination", dstSchema.ToString());
         return TConclusionStatus::Fail("incorrect columns set: destination must been wider than source");
     }
     std::set<ui32> fieldIdx;
     auto itSrc = srcBatch->schema()->fields().begin();
-    auto itDst = dstSchema->fields().begin();
-    while (itSrc != srcBatch->schema()->fields().end() && itDst != dstSchema->fields().end()) {
+    auto itDst = dstSchema.begin();
+    while (itSrc != srcBatch->schema()->fields().end() && itDst != dstSchema.end()) {
         if ((*itSrc)->name() != (*itDst)->name()) {
             ++itDst;
         } else {
-            fieldIdx.emplace(itDst - dstSchema->fields().begin());
+            fieldIdx.emplace(itDst - dstSchema.begin());
             if (checkFieldTypesPolicy != TColumnOperator::ECheckFieldTypesPolicy::Ignore && (*itDst)->Equals(*itSrc)) {
                 switch (checkFieldTypesPolicy) {
                     case TColumnOperator::ECheckFieldTypesPolicy::Error: {
@@ -245,25 +244,24 @@ TConclusion<TSchemaSubset> BuildSequentialSubsetImpl(const std::shared_ptr<TData
             ++itSrc;
         }
     }
-    if (itDst == dstSchema->fields().end() && itSrc != srcBatch->schema()->fields().end()) {
+    if (itDst == dstSchema.end() && itSrc != srcBatch->schema()->fields().end()) {
         AFL_ERROR(NKikimrServices::ARROW_HELPER)("event", "incorrect columns order in source set")("source", srcBatch->schema()->ToString())(
-            "destination", dstSchema->ToString());
+            "destination", dstSchema.ToString());
         return TConclusionStatus::Fail("incorrect columns order in source set");
     }
-    return TSchemaSubset(fieldIdx, dstSchema->num_fields());
+    return TSchemaSubset(fieldIdx, dstSchema.num_fields());
 }
 }   // namespace
 
 TConclusion<TSchemaSubset> TColumnOperator::BuildSequentialSubset(
-    const std::shared_ptr<arrow::RecordBatch>& incoming, const std::shared_ptr<NArrow::TSchemaLite>& dstSchema) {
+    const std::shared_ptr<arrow::RecordBatch>& incoming, const NArrow::TSchemaLiteView& dstSchema) {
     return BuildSequentialSubsetImpl(incoming, dstSchema, DifferentColumnTypesPolicy);
 }
 namespace {
 template <class TDataContainer>
 TConclusion<std::shared_ptr<TDataContainer>> AdaptIncomingToDestinationExtImpl(const std::shared_ptr<TDataContainer>& incoming,
-    const std::shared_ptr<TSchemaLite>& dstSchema, const std::function<TConclusionStatus(const ui32, const i32)>& checker,
-    const std::function<i32(const std::string&)>& nameResolver,
-    const TColumnOperator::ECheckFieldTypesPolicy differentColumnTypesPolicy,
+    const TSchemaLiteView& dstSchema, const std::function<TConclusionStatus(const ui32, const i32)>& checker,
+    const std::function<i32(const std::string&)>& nameResolver, const TColumnOperator::ECheckFieldTypesPolicy differentColumnTypesPolicy,
     const TColumnOperator::EAbsentFieldPolicy absentColumnPolicy) {
     struct TFieldData {
         ui32 Index;
@@ -273,14 +271,13 @@ TConclusion<std::shared_ptr<TDataContainer>> AdaptIncomingToDestinationExtImpl(c
         }
     };
     AFL_VERIFY(incoming);
-    AFL_VERIFY(dstSchema);
     std::vector<TFieldData> resultColumns;
     resultColumns.reserve(incoming->num_columns());
     ui32 idx = 0;
     for (auto& srcField : incoming->schema()->fields()) {
         const int dstIndex = nameResolver(srcField->name());
         if (dstIndex > -1) {
-            const auto& dstField = dstSchema->GetFieldByIndexVerified(dstIndex);
+            const auto& dstField = dstSchema.GetFieldByIndexVerified(dstIndex);
             switch (differentColumnTypesPolicy) {
                 case TColumnOperator::ECheckFieldTypesPolicy::Verify:
                     AFL_VERIFY(dstField->type()->Equals(srcField->type()))("event", "cannot_use_incoming_batch")("reason", "invalid_column_type")(
@@ -322,14 +319,14 @@ TConclusion<std::shared_ptr<TDataContainer>> AdaptIncomingToDestinationExtImpl(c
     columns.reserve(resultColumns.size());
     fields.reserve(resultColumns.size());
     for (auto&& i : resultColumns) {
-        fields.emplace_back(dstSchema->field(i.Index));
+        fields.emplace_back(dstSchema.field(i.Index));
         columns.emplace_back(i.Column);
     }
     return NAdapter::TDataBuilderPolicy<TDataContainer>::Build(std::make_shared<arrow::Schema>(fields), std::move(columns), incoming->num_rows());
 }
 }   // namespace
 TConclusion<std::shared_ptr<arrow::RecordBatch>> TColumnOperator::AdaptIncomingToDestinationExt(
-    const std::shared_ptr<arrow::RecordBatch>& incoming, const std::shared_ptr<TSchemaLite>& dstSchema,
+    const std::shared_ptr<arrow::RecordBatch>& incoming, const TSchemaLiteView& dstSchema,
     const std::function<TConclusionStatus(const ui32, const i32)>& checker, const std::function<i32(const std::string&)>& nameResolver) const {
     return AdaptIncomingToDestinationExtImpl(incoming, dstSchema, checker, nameResolver, DifferentColumnTypesPolicy, AbsentColumnPolicy);
 }

ydb/core/formats/arrow/process_columns.h

@@ -8,6 +8,7 @@ namespace NKikimr::NArrow {
 
 class TSchemaSubset;
 class TSchemaLite;
+class TSchemaLiteView;
 
 class TColumnOperator {
 public:
@@ -59,7 +60,7 @@ class TColumnOperator {
     }
 
     TConclusion<std::shared_ptr<arrow::RecordBatch>> AdaptIncomingToDestinationExt(const std::shared_ptr<arrow::RecordBatch>& incoming,
-        const std::shared_ptr<TSchemaLite>& dstSchema, const std::function<TConclusionStatus(const ui32, const i32)>& checker,
+        const TSchemaLiteView& dstSchema, const std::function<TConclusionStatus(const ui32, const i32)>& checker,
         const std::function<i32(const std::string&)>& nameResolver) const;
 
     std::shared_ptr<arrow::RecordBatch> Extract(
@@ -73,7 +74,7 @@ class TColumnOperator {
     std::shared_ptr<arrow::Table> Extract(const std::shared_ptr<arrow::Table>& incoming, const std::vector<TString>& columnNames);
 
     TConclusion<TSchemaSubset> BuildSequentialSubset(
-        const std::shared_ptr<arrow::RecordBatch>& incoming, const std::shared_ptr<NArrow::TSchemaLite>& dstSchema);
+        const std::shared_ptr<arrow::RecordBatch>& incoming, const NArrow::TSchemaLiteView& dstSchema);
 
     TConclusion<std::shared_ptr<arrow::RecordBatch>> Adapt(
         const std::shared_ptr<arrow::RecordBatch>& incoming, const std::shared_ptr<arrow::Schema>& dstSchema, TSchemaSubset* subset = nullptr);

ydb/core/tx/columnshard/columnshard__propose_transaction.cpp

@@ -146,7 +146,6 @@ class TTxProposeTransaction: public NTabletFlatExecutor::TTransactionBase<TColum
             }
 
             auto schemaSnapshot = Self->TablesManager.GetPrimaryIndexSafe().GetVersionedIndex().GetLastSchema();
-            auto schema = schemaSnapshot->GetSchema();
             auto index = schemaSnapshot->GetColumnIdOptional(columnName);
             if (!index) {
                 return TTxController::TProposeResult(

ydb/core/tx/columnshard/engines/changes/indexation.cpp

@@ -108,7 +108,8 @@ class TPathFieldsInfo {
         if (!Schemas.contains(data.GetSchemaVersion())) {
             Schemas.emplace(data.GetSchemaVersion(), blobSchema);
         }
-        std::vector<ui32> filteredIds = data.GetMeta().GetSchemaSubset().Apply(blobSchema->GetIndexInfo().GetColumnIds(false));
+        auto columnIds = blobSchema->GetIndexInfo().GetColumnIds(false);
+        std::vector<ui32> filteredIds = data.GetMeta().GetSchemaSubset().Apply(columnIds.begin(), columnIds.end());
         if (data.GetMeta().GetModificationType() == NEvWrite::EModificationType::Delete) {
             filteredIds.emplace_back((ui32)IIndexInfo::ESpecialColumn::DELETE_FLAG);
         }
@@ -245,8 +246,10 @@ TConclusionStatus TInsertColumnEngineChanges::DoConstructBlobs(TConstructionCont
         std::shared_ptr<NArrow::TGeneralContainer> batch;
         {
             const auto blobData = Blobs.Extract(IStoragesManager::DefaultStorageId, blobRange);
+
+            auto blobSchemaView = blobSchema->GetIndexInfo().ArrowSchema();
             auto batchSchema =
-                std::make_shared<arrow::Schema>(inserted.GetMeta().GetSchemaSubset().Apply(blobSchema->GetIndexInfo().ArrowSchema()->fields()));
+                std::make_shared<arrow::Schema>(inserted.GetMeta().GetSchemaSubset().Apply(blobSchemaView.begin(), blobSchemaView.end()));
             batch = std::make_shared<NArrow::TGeneralContainer>(NArrow::DeserializeBatch(blobData, batchSchema));
             std::set<ui32> columnIdsToDelete = blobSchema->GetColumnIdsToDelete(resultSchema);
             if (!columnIdsToDelete.empty()) {

ydb/core/tx/columnshard/engines/reader/abstract/read_metadata.h

@@ -118,7 +118,7 @@ class TReadMetadataBase {
 
     ISnapshotSchema::TPtr GetLoadSchemaVerified(const TPortionInfo& porition) const;
 
-    const std::shared_ptr<NArrow::TSchemaLite>& GetBlobSchema(const ui64 version) const {
+    NArrow::TSchemaLiteView GetBlobSchema(const ui64 version) const {
         return GetIndexVersions().GetSchemaVerified(version)->GetIndexInfo().ArrowSchema();
     }
 

ydb/core/tx/columnshard/engines/reader/common_reader/constructor/read_metadata.h

@@ -131,15 +131,6 @@ class TReadMetadata: public TReadMetadataBase {
     TConclusionStatus Init(
         const NColumnShard::TColumnShard* owner, const TReadDescription& readDescription, const TDataStorageAccessor& dataAccessor);
 
-    std::vector<std::string> GetColumnsOrder() const {
-        auto schema = GetResultSchema();
-        std::vector<std::string> result;
-        for (auto&& i : schema->GetSchema()->fields()) {
-            result.emplace_back(i->name());
-        }
-        return result;
-    }
-
     std::set<ui32> GetEarlyFilterColumnIds() const;
     std::set<ui32> GetPKColumnIds() const;
 

ydb/core/tx/columnshard/engines/reader/plain_reader/iterator/source.cpp

@@ -273,8 +273,8 @@ void TCommittedDataSource::DoAssembleColumns(const std::shared_ptr<TColumnsSet>&
         AFL_VERIFY(GetStageData().GetBlobs().size() == 1);
         auto bData = MutableStageData().ExtractBlob(GetStageData().GetBlobs().begin()->first);
         auto schema = GetContext()->GetReadMetadata()->GetBlobSchema(CommittedBlob.GetSchemaVersion());
-        auto rBatch = NArrow::DeserializeBatch(bData, std::make_shared<arrow::Schema>(CommittedBlob.GetSchemaSubset().Apply(schema->fields())));
-        AFL_VERIFY(rBatch)("schema", schema->ToString());
+        auto rBatch = NArrow::DeserializeBatch(bData, std::make_shared<arrow::Schema>(CommittedBlob.GetSchemaSubset().Apply(schema.begin(), schema.end())));
+        AFL_VERIFY(rBatch)("schema", schema.ToString());
         auto batch = std::make_shared<NArrow::TGeneralContainer>(rBatch);
         std::set<ui32> columnIdsToDelete = batchSchema->GetColumnIdsToDelete(resultSchema);
         if (!columnIdsToDelete.empty()) {

ydb/core/tx/columnshard/engines/scheme/abstract/column_ids.cpp

@@ -0,0 +1,3 @@
+#include "column_ids.h"
+
+namespace NKikimr::NOlap {}

ydb/core/tx/columnshard/engines/scheme/abstract/column_ids.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <ydb/library/actors/core/log.h>
+#include <ydb/library/formats/arrow/common/iterator.h>
+
+#include <util/generic/noncopyable.h>
+#include <util/system/types.h>
+
+#include <span>
+
+namespace NKikimr::NOlap {
+
+class TColumnIdsView: private TNonCopyable {
+private:
+    std::span<const ui32> ColumnIds;
+
+    class TIterator: public NArrow::NUtil::TRandomAccessIteratorClone<std::span<const ui32>::iterator, TIterator> {
+        using TBase = NArrow::NUtil::TRandomAccessIteratorClone<std::span<const ui32>::iterator, TIterator>;
+
+    public:
+        using TBase::TRandomAccessIteratorClone;
+    };
+
+public:
+    template <typename It>
+    TColumnIdsView(const It begin, const It end)
+        : ColumnIds(begin, end) {
+    }
+
+    TIterator begin() const {
+        return ColumnIds.begin();
+    }
+
+    TIterator end() const {
+        return ColumnIds.end();
+    }
+
+    ui32 operator[](size_t idx) const {
+        AFL_VERIFY(idx < ColumnIds.size())("idx", idx)("size", ColumnIds.size());
+        return ColumnIds[idx];
+    }
+
+    ui64 size() const {
+        return ColumnIds.size();
+    }
+};
+
+}   // namespace NKikimr::NOlap

ydb/core/tx/columnshard/engines/scheme/abstract/index_info.h

@@ -120,11 +120,9 @@ class IIndexInfo {
         return result;
     }
 
-    [[nodiscard]] static std::vector<ui32> AddSpecialFieldIds(const std::vector<ui32>& baseColumnIds) {
-        std::vector<ui32> result = baseColumnIds;
+    static void AddSpecialFieldIds(std::vector<ui32>& baseColumnIds) {
         const auto& cIds = GetSystemColumnIds();
-        result.insert(result.end(), cIds.begin(), cIds.end());
-        return result;
+        baseColumnIds.insert(baseColumnIds.end(), cIds.begin(), cIds.end());
     }
 
     [[nodiscard]] static std::set<ui32> AddSpecialFieldIds(const std::set<ui32>& baseColumnIds) {

ydb/core/tx/columnshard/engines/scheme/abstract/ya.make

@@ -2,6 +2,7 @@ LIBRARY()
 
 SRCS(
     index_info.cpp
+    column_ids.cpp
 )
 
 PEERDIR(