KIKIMR-19521 BTreeIndex ShortChild

Экономия ~26% для групп и ~16% для истории

6 files changed, 113 insertions, 56 deletions

diff --git a/ydb/core/tablet_flat/flat_page_btree_index.h b/ydb/core/tablet_flat/flat_page_btree_index.h
index 51e4902d53..968fb5f9c7 100644
--- a/ydb/core/tablet_flat/flat_page_btree_index.h
+++ b/ydb/core/tablet_flat/flat_page_btree_index.h
@@ -53,7 +53,10 @@ namespace NKikimr::NTable::NPage {
         struct THeader {
             TRecIdx KeysCount;
             TPgSize KeysSize;
-            ui8 FixedKeySize;
+            ui8 IsShortChildFormat : 1;
+            ui8 FixedKeySize : 7;
+            
+            const static ui8 MaxFixedKeySize = 127;
         } Y_PACKED;
 
         static_assert(sizeof(THeader) == 9, "Invalid TBtreeIndexNode THeader size");
@@ -80,23 +83,36 @@ namespace NKikimr::NTable::NPage {
 
         static_assert(sizeof(TIsNullBitmap) == 1, "Invalid TBtreeIndexNode TIsNullBitmap size");
 
+        struct TShortChild {
+            TPageId PageId;
+            TRowId Count;
+            ui64 DataSize;
+
+            auto operator<=>(const TShortChild&) const = default;
+        } Y_PACKED;
+
+        static_assert(sizeof(TShortChild) == 20, "Invalid TBtreeIndexNode TShortChild size");
+
         struct TChild {
             TPageId PageId;
             TRowId Count;
-            TRowId ErasedCount;
             ui64 DataSize;
+            TRowId ErasedCount;
 
             auto operator<=>(const TChild&) const = default;
 
             TString ToString() const noexcept
             {
-                // copy values to prevent 'reference binding to misaligned address' error
-                return TStringBuilder() << "PageId: " << TPageId(PageId) << " Count: " << TRowId(Count) << " Erased: " << TRowId(ErasedCount) << " DataSize: " << ui64(DataSize);
+                return TStringBuilder() << "PageId: " << PageId << " Count: " << Count << " DataSize: " << DataSize << " Erased: " << ErasedCount;
             }
         } Y_PACKED;
 
         static_assert(sizeof(TChild) == 28, "Invalid TBtreeIndexNode TChild size");
 
+        static_assert(offsetof(TChild, PageId) == offsetof(TShortChild, PageId));
+        static_assert(offsetof(TChild, Count) == offsetof(TShortChild, Count));
+        static_assert(offsetof(TChild, DataSize) == offsetof(TShortChild, DataSize));
+
 #pragma pack(pop)
 
         struct TCellsIter {
@@ -242,7 +258,7 @@ namespace NKikimr::NTable::NPage {
             offset += Header->KeysSize;
 
             Children = TDeref<const TChild>::At(Header, offset);
-            offset += (1 + Header->KeysCount) * sizeof(TChild);
+            offset += (1 + Header->KeysCount) * (Header->IsShortChildFormat ? sizeof(TShortChild) : sizeof(TChild));
 
             Y_ABORT_UNLESS(offset == data.Page.size());
         }
@@ -254,7 +270,7 @@ namespace NKikimr::NTable::NPage {
 
         bool IsFixedFormat() const noexcept
         {
-            return Header->FixedKeySize != Max<ui8>();
+            return Header->FixedKeySize != Header->MaxFixedKeySize;
         }
 
         TRecIdx GetKeysCount() const noexcept
@@ -277,9 +293,23 @@ namespace NKikimr::NTable::NPage {
             return GetCells<TCellsIter>(pos, columns);
         }
 
-        const TChild& GetChild(TRecIdx pos) const noexcept
+        const TShortChild& GetShortChild(TRecIdx pos) const noexcept
         {
-            return Children[pos];
+            if (Header->IsShortChildFormat) {
+                return *TDeref<const TShortChild>::At(Children, pos * sizeof(TShortChild));
+            } else {
+                return *TDeref<const TShortChild>::At(Children, pos * sizeof(TChild));
+            }
+        }
+
+        TChild GetChild(TRecIdx pos) const noexcept
+        {
+            if (Header->IsShortChildFormat) {
+                const TShortChild* const shortChild = TDeref<const TShortChild>::At(Children, pos * sizeof(TShortChild));
+                return { shortChild->PageId, shortChild->Count, shortChild->DataSize, 0 };
+            } else {
+                return *TDeref<const TChild>::At(Children, pos * sizeof(TChild));
+            }
         }
 
         static bool Has(TRowId rowId, TRowId beginRowId, TRowId endRowId) noexcept {
@@ -294,27 +324,27 @@ namespace NKikimr::NTable::NPage {
                 on = { };
             }
 
-            const auto cmp = [](TRowId rowId, const TChild& child) {
-                return rowId < child.Count;
+            auto range = xrange(0u, childrenCount);
+            const auto cmp = [this](TRowId rowId, TPos pos) {
+                return rowId < GetShortChild(pos).Count;
             };
 
             TRecIdx result;
             if (!on) {
-                // Use a full binary search
-                result = std::upper_bound(Children, Children + childrenCount, rowId, cmp) - Children;
-            } else if (Children[*on].Count <= rowId) {
+                // Will do a full binary search on full range
+            } else if (GetShortChild(*on).Count <= rowId) {
                 // Try a short linear search first
                 result = *on;
                 for (int linear = 0; linear < 4; ++linear) {
                     result++;
                     Y_ABORT_UNLESS(result < childrenCount, "Should always seek some child");
-                    if (Children[result].Count > rowId) {
+                    if (GetShortChild(result).Count > rowId) {
                         return result;
                     }
                 }
 
-                // Binary search from the next record
-                result = std::upper_bound(Children + result + 1, Children + childrenCount, rowId, cmp) - Children;
+                // Will do a binary search from the next record
+                range = xrange(result + 1, childrenCount);
             } else { // Children[*on].Count > rowId
                 // Try a short linear search first
                 result = *on;
@@ -322,16 +352,18 @@ namespace NKikimr::NTable::NPage {
                     if (result == 0) {
                         return 0;
                     }
-                    if (Children[result - 1].Count <= rowId) {
+                    if (GetShortChild(result - 1).Count <= rowId) {
                         return result;
                     }
                     result--;
                 }
 
-                // Binary search up to current record
-                result = std::upper_bound(Children, Children + result, rowId, cmp) - Children;
+                // Will do a binary search up to current record
+                range = xrange(0u, result);
             }
 
+            result = *std::upper_bound(range.begin(), range.end(), rowId, cmp);
+
             Y_ABORT_UNLESS(result < childrenCount, "Should always seek some child");
             return result;
         }
@@ -428,7 +460,7 @@ namespace NKikimr::NTable::NPage {
         const THeader* Header = nullptr;
         const void* Keys = nullptr;
         const TRecordsEntry* Offsets = nullptr;
-        const TChild* Children = nullptr;
+        const void* Children = nullptr;
     };
 
     struct TBtreeIndexMeta : public TBtreeIndexNode::TChild {
diff --git a/ydb/core/tablet_flat/flat_page_btree_index_writer.h b/ydb/core/tablet_flat/flat_page_btree_index_writer.h
index fd855f18f9..0c7b084f05 100644
--- a/ydb/core/tablet_flat/flat_page_btree_index_writer.h
+++ b/ydb/core/tablet_flat/flat_page_btree_index_writer.h
@@ -8,6 +8,7 @@ namespace NKikimr::NTable::NPage {
     class TBtreeIndexNodeWriter {
         using THeader = TBtreeIndexNode::THeader;
         using TIsNullBitmap = TBtreeIndexNode::TIsNullBitmap;
+        using TShortChild = TBtreeIndexNode::TShortChild;
         using TChild = TBtreeIndexNode::TChild;
 
     public:
@@ -17,20 +18,26 @@ namespace NKikimr::NTable::NPage {
             , GroupInfo(Scheme->GetLayout(groupId))
         {
             if (GroupId.IsMain()) {
-                FixedKeySize = Max<ui8>();
+                // TODO: some main groups without nulls and var-sized cells also may use fixed format
+                FixedKeySize = TBtreeIndexNode::THeader::MaxFixedKeySize;
             } else {
                 FixedKeySize = 0;
                 for (TPos pos : xrange(GroupInfo.KeyTypes.size())) {
                     Y_ABORT_UNLESS(GroupInfo.ColsKeyIdx[pos].IsFixed);
                     FixedKeySize += GroupInfo.ColsKeyIdx[pos].FixedSize;
                 }
-                Y_ABORT_UNLESS(FixedKeySize < Max<ui8>(), "KeysSize is out of bounds");
+                Y_ABORT_UNLESS(FixedKeySize < TBtreeIndexNode::THeader::MaxFixedKeySize, "FixedKeySize is out of bounds");
             }
         }
 
         bool IsFixedFormat() const noexcept
         {
-            return FixedKeySize != Max<ui8>();
+            return FixedKeySize != TBtreeIndexNode::THeader::MaxFixedKeySize;
+        }
+
+        bool IsShortChildFormat() const noexcept
+        {
+            return !GroupId.IsMain();
         }
 
         void AddKey(TCellsRef cells) {
@@ -43,6 +50,7 @@ namespace NKikimr::NTable::NPage {
         }
 
         void AddChild(TChild child) {
+            Y_ABORT_UNLESS(child.ErasedCount == 0 || !IsShortChildFormat(), "Short format can't have ErasedCount");
             Children.push_back(child);
         }
 
@@ -95,6 +103,7 @@ namespace NKikimr::NTable::NPage {
             header.KeysCount = Keys.size();
             Y_ABORT_UNLESS(KeysSize < Max<TPgSize>(), "KeysSize is out of bounds");
             header.KeysSize = KeysSize;
+            header.IsShortChildFormat = IsShortChildFormat();
             header.FixedKeySize = FixedKeySize;
 
             if (!IsFixedFormat()) {
@@ -118,7 +127,10 @@ namespace NKikimr::NTable::NPage {
             Keys.clear();
             KeysSize = 0;
 
-            PlaceVector(Children);
+            for (auto &child : Children) {
+                PlaceChild(child);
+            }
+            Children.clear();
 
             Y_ABORT_UNLESS(Ptr == End);
             NSan::CheckMemIsInitialized(buf.data(), buf.size());
@@ -137,7 +149,7 @@ namespace NKikimr::NTable::NPage {
                 sizeof(TLabel) + sizeof(THeader) +
                 (IsFixedFormat() ? 0 : sizeof(TRecordsEntry) * keysCount) +
                 keysSize +
-                sizeof(TChild) * (keysCount + 1);
+                (IsShortChildFormat() ? sizeof(TShortChild) : sizeof(TChild)) * (keysCount + 1);
         }
 
         size_t GetKeysCount() const {
@@ -145,7 +157,10 @@ namespace NKikimr::NTable::NPage {
         }
 
         TPgSize CalcKeySizeWithMeta(TCellsRef cells) const noexcept {
-            return sizeof(TRecordsEntry) + CalcKeySize(cells) + sizeof(TChild);
+            return 
+                sizeof(TRecordsEntry) + 
+                CalcKeySize(cells) + 
+                (IsShortChildFormat() ? sizeof(TShortChild) : sizeof(TChild));
         }
 
     private:
@@ -231,12 +246,13 @@ namespace NKikimr::NTable::NPage {
             std::copy(data.data(), data.data() + data.size(), Advance(data.size()));
         }
 
-        template<typename T>
-        void PlaceVector(TVector<T> &vector) noexcept
+        void PlaceChild(const TChild& child) noexcept
         {
-            auto *dst = reinterpret_cast<T*>(Advance(sizeof(T)*vector.size()));
-            std::copy(vector.begin(), vector.end(), dst);
-            vector.clear();
+            if (IsShortChildFormat()) {
+                Place<TShortChild>() = TShortChild{child.PageId, child.Count, child.DataSize};
+            } else {
+                Place<TChild>() = child;
+            }
         }
 
         template<typename T>
@@ -277,6 +293,7 @@ namespace NKikimr::NTable::NPage {
 
     class TBtreeIndexBuilder {
     public:
+        using TShortChild = TBtreeIndexNode::TShortChild;
         using TChild = TBtreeIndexNode::TChild;
 
     private:
@@ -357,11 +374,15 @@ namespace NKikimr::NTable::NPage {
             Levels[0].PushKey(Writer.SerializeKey(cells));
         }
 
+        void AddShortChild(TShortChild child) {
+            AddChild(TChild{child.PageId, child.Count, child.DataSize, 0});
+        }
+
         void AddChild(TChild child) {
             // aggregate in order to perform search by row id from any leaf node
             child.Count = (ChildrenCount += child.Count);
-            child.ErasedCount = (ChildrenErasedCount += child.ErasedCount);
             child.DataSize = (ChildrenSize += child.DataSize);
+            child.ErasedCount = (ChildrenErasedCount += child.ErasedCount);
 
             Levels[0].PushChild(child);
         }
@@ -441,7 +462,7 @@ namespace NKikimr::NTable::NPage {
             if (levelIndex + 1 == Levels.size()) {
                 Levels.emplace_back();
             }
-            Levels[levelIndex + 1].PushChild(TChild{pageId, lastChild.Count, lastChild.ErasedCount, lastChild.DataSize});
+            Levels[levelIndex + 1].PushChild(TChild{pageId, lastChild.Count, lastChild.DataSize, lastChild.ErasedCount});
             if (!last) {
                 Levels[levelIndex + 1].PushKey(Levels[levelIndex].PopKey());
             }
diff --git a/ydb/core/tablet_flat/flat_part_loader.cpp b/ydb/core/tablet_flat/flat_part_loader.cpp
index 3e636dcb4b..b6de80b949 100644
--- a/ydb/core/tablet_flat/flat_part_loader.cpp
+++ b/ydb/core/tablet_flat/flat_part_loader.cpp
@@ -83,8 +83,8 @@ void TLoader::StageParseMeta() noexcept
                 NPage::TBtreeIndexMeta converted{{
                     meta.GetRootPageId(), 
                     meta.GetCount(), 
-                    meta.GetErasedCount(), 
-                    meta.GetDataSize()}, 
+                    meta.GetDataSize(), 
+                    meta.GetErasedCount()}, 
                     meta.GetLevelsCount(), 
                     meta.GetIndexSize()};
                 (history ? BTreeHistoricIndexes : BTreeGroupIndexes).push_back(converted);
diff --git a/ydb/core/tablet_flat/flat_part_writer.h b/ydb/core/tablet_flat/flat_part_writer.h
index 4b2e4723da..e35c2979b0 100644
--- a/ydb/core/tablet_flat/flat_part_writer.h
+++ b/ydb/core/tablet_flat/flat_part_writer.h
@@ -796,11 +796,10 @@ namespace NTable {
                         g.BTreeIndex.AddKey(Key);
                     }
                     if (groupId.IsMain()) {
-                        g.BTreeIndex.AddChild({page, dataPage->Count, Current.BTreeIndexErased, raw.size()});
+                        g.BTreeIndex.AddChild({page, dataPage->Count, raw.size(), Current.BTreeIndexErased});
                         Current.BTreeIndexErased = 0;
                     } else {
-                        // TODO: don't write erased for non-main groups
-                        g.BTreeIndex.AddChild({page, dataPage->Count, 0, raw.size()});
+                        g.BTreeIndex.AddShortChild({page, dataPage->Count, raw.size()});
                     }
                     g.BTreeIndex.Flush(Pager, false);
                 }
diff --git a/ydb/core/tablet_flat/test/libs/table/test_writer.h b/ydb/core/tablet_flat/test/libs/table/test_writer.h
index cf1567b699..4a49364708 100644
--- a/ydb/core/tablet_flat/test/libs/table/test_writer.h
+++ b/ydb/core/tablet_flat/test/libs/table/test_writer.h
@@ -130,8 +130,8 @@ namespace NTest {
                     NPage::TBtreeIndexMeta converted{{
                         meta.GetRootPageId(), 
                         meta.GetCount(), 
-                        meta.GetErasedCount(), 
-                        meta.GetDataSize()}, 
+                        meta.GetDataSize(), 
+                        meta.GetErasedCount()}, 
                         meta.GetLevelsCount(), 
                         meta.GetIndexSize()};
                     (history ? BTreeHistoricIndexes : BTreeGroupIndexes).push_back(converted);
diff --git a/ydb/core/tablet_flat/ut/ut_btree_index.cpp b/ydb/core/tablet_flat/ut/ut_btree_index.cpp
index e80a41b900..45d173db70 100644
--- a/ydb/core/tablet_flat/ut/ut_btree_index.cpp
+++ b/ydb/core/tablet_flat/ut/ut_btree_index.cpp
@@ -9,6 +9,7 @@ namespace NKikimr::NTable::NPage {
 
 namespace {
     using namespace NTest;
+    using TShortChild = TBtreeIndexNode::TShortChild;
     using TChild = TBtreeIndexNode::TChild;
 
     struct TTouchEnv : public NTest::TTestEnv {
@@ -68,7 +69,7 @@ namespace {
     }
 
     TChild MakeChild(ui32 index) {
-        return TChild{index + 10000, index + 100, index + 30, index + 1000};
+        return TChild{index + 10000, index + 100, index + 1000, index + 30};
     }
 
     void Dump(TChild meta, const TPartScheme::TGroupInfo& groupInfo, const TStore& store, ui32 level = 0) noexcept
@@ -154,6 +155,8 @@ namespace {
         UNIT_ASSERT_VALUES_EQUAL(node.GetKeysCount() + 1, children.size());
         for (TRecIdx i : xrange(node.GetKeysCount() + 1)) {
             UNIT_ASSERT_EQUAL(node.GetChild(i), children[i]);
+            TShortChild shortChild{children[i].PageId, children[i].Count, children[i].DataSize};
+            UNIT_ASSERT_EQUAL(node.GetShortChild(i), shortChild);
         }
     }
 }
@@ -291,7 +294,8 @@ Y_UNIT_TEST_SUITE(TBtreeIndexNode) {
             TSerializedCellVec deserialized(k);
             writer.AddKey(deserialized.GetCells());
         }
-        for (auto c : children) {
+        for (auto &c : children) {
+            c.ErasedCount = 0;
             writer.AddChild(c);
         }
 
@@ -335,7 +339,8 @@ Y_UNIT_TEST_SUITE(TBtreeIndexNode) {
             TSerializedCellVec deserialized(k);
             writer.AddKey(deserialized.GetCells());
         }
-        for (auto c : children) {
+        for (auto &c : children) {
+            c.ErasedCount = 0;
             writer.AddChild(c);
         }
 
@@ -534,7 +539,7 @@ Y_UNIT_TEST_SUITE(TBtreeIndexBuilder) {
 
         Dump(*result, builder.GroupInfo, pager.Back());
 
-        TBtreeIndexMeta expected{{0, 1155, 385, 11055}, 1, 595};
+        TBtreeIndexMeta expected{{0, 1155, 11055, 385}, 1, 595};
         UNIT_ASSERT_EQUAL_C(*result, expected, "Got " + result->ToString());
 
         CheckKeys(result->PageId, keys, builder.GroupInfo, pager.Back());
@@ -621,8 +626,8 @@ Y_UNIT_TEST_SUITE(TBtreeIndexBuilder) {
         TBtreeIndexMeta expected{{9, 0, 0, 0}, 3, 1550};
         for (auto c : children) {
             expected.Count += c.Count;
-            expected.ErasedCount += c.ErasedCount;
             expected.DataSize += c.DataSize;
+            expected.ErasedCount += c.ErasedCount;
         }
         UNIT_ASSERT_EQUAL_C(*result, expected, "Got " + result->ToString());
     }
@@ -657,7 +662,7 @@ Y_UNIT_TEST_SUITE(TBtreeIndexBuilder) {
 
         Dump(*result, builder.GroupInfo, pager.Back());
         
-        TBtreeIndexMeta expected{{15, 15150, 8080, 106050}, 3, 10270};
+        TBtreeIndexMeta expected{{15, 15150, 106050, 8080}, 3, 10270};
         UNIT_ASSERT_EQUAL_C(*result, expected, "Got " + result->ToString());
     }
 
@@ -691,7 +696,7 @@ Y_UNIT_TEST_SUITE(TBtreeIndexTPart) {
         auto pages = IndexTools::CountMainPages(*part);
         UNIT_ASSERT_VALUES_EQUAL(pages, 1);
 
-        TBtreeIndexMeta expected{{0 /*Data page*/, 5, 0, 5240}, 0, 0};
+        TBtreeIndexMeta expected{{0 /*Data page*/, 5, 5240, 0}, 0, 0};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[0], expected, "Got " + part->IndexPages.BTreeGroups[0].ToString());
     }
 
@@ -721,7 +726,7 @@ Y_UNIT_TEST_SUITE(TBtreeIndexTPart) {
         auto pages = IndexTools::CountMainPages(*part);
         UNIT_ASSERT_VALUES_EQUAL(pages, 2);
 
-        TBtreeIndexMeta expected{{3, 10, 0, 10480}, 1, 1115};
+        TBtreeIndexMeta expected{{3, 10, 10480, 0}, 1, 1115};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[0], expected, "Got " + part->IndexPages.BTreeGroups[0].ToString());
     }
 
@@ -754,7 +759,7 @@ Y_UNIT_TEST_SUITE(TBtreeIndexTPart) {
         auto pages = IndexTools::CountMainPages(*part);
         UNIT_ASSERT_VALUES_EQUAL(pages, 117);
 
-        TBtreeIndexMeta expected{{143, 700, 0, 733140}, 3, 86036};
+        TBtreeIndexMeta expected{{143, 700, 733140, 0}, 3, 86036};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[0], expected, "Got " + part->IndexPages.BTreeGroups[0].ToString());
     }
 
@@ -788,7 +793,7 @@ Y_UNIT_TEST_SUITE(TBtreeIndexTPart) {
         auto pages = IndexTools::CountMainPages(*part);
         UNIT_ASSERT_VALUES_EQUAL(pages, 31);
 
-        TBtreeIndexMeta expected{{37, 1000, 143, 22098}, 2, 1380};
+        TBtreeIndexMeta expected{{37, 1000, 22098, 143}, 2, 1380};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[0], expected, "Got " + part->IndexPages.BTreeGroups[0].ToString());
     }
 
@@ -822,10 +827,10 @@ Y_UNIT_TEST_SUITE(TBtreeIndexTPart) {
         auto pages = IndexTools::CountMainPages(*part);
         UNIT_ASSERT_VALUES_EQUAL(pages, 334);
 
-        TBtreeIndexMeta expected0{{438, 1000, 0, 16680}, 3, 15246};
+        TBtreeIndexMeta expected0{{438, 1000, 16680, 0}, 3, 15246};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[0], expected0, "Got " + part->IndexPages.BTreeGroups[0].ToString());
 
-        TBtreeIndexMeta expected1{{441, 1000, 0, 21890}, 3, 8817};
+        TBtreeIndexMeta expected1{{441, 1000, 21890, 0}, 3, 6497};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[1], expected1, "Got " + part->IndexPages.BTreeGroups[1].ToString());
     }
 
@@ -861,16 +866,16 @@ Y_UNIT_TEST_SUITE(TBtreeIndexTPart) {
         auto pages = IndexTools::CountMainPages(*part);
         UNIT_ASSERT_VALUES_EQUAL(pages, 334);
 
-        TBtreeIndexMeta expected0{{1315, 1000, 0, 32680}, 3, 15246};
+        TBtreeIndexMeta expected0{{1315, 1000, 32680, 0}, 3, 15246};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[0], expected0, "Got " + part->IndexPages.BTreeGroups[0].ToString());
 
-        TBtreeIndexMeta expected1{{1318, 1000, 0, 22889}, 3, 8817};
+        TBtreeIndexMeta expected1{{1318, 1000, 22889, 0}, 3, 6497};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeGroups[1], expected1, "Got " + part->IndexPages.BTreeGroups[1].ToString());
 
-        TBtreeIndexMeta expectedHist0{{1322, 2000, 0, 77340}, 4, 40617};
+        TBtreeIndexMeta expectedHist0{{1322, 2000, 77340, 0}, 4, 34225};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeHistoric[0], expectedHist0, "Got " + part->IndexPages.BTreeHistoric[0].ToString());
 
-        TBtreeIndexMeta expectedHist1{{1325, 2000, 0, 45780}, 3, 17662};
+        TBtreeIndexMeta expectedHist1{{1325, 2000, 45780, 0}, 3, 13014};
         UNIT_ASSERT_EQUAL_C(part->IndexPages.BTreeHistoric[1], expectedHist1, "Got " + part->IndexPages.BTreeHistoric[1].ToString());
     }
 }