diff --git a/dbms/src/Storages/MergeTree/IMergeTreeDataPart.cpp b/dbms/src/Storages/MergeTree/IMergeTreeDataPart.cpp
index bce4e51dd49..196f73484c8 100644
--- a/dbms/src/Storages/MergeTree/IMergeTreeDataPart.cpp
+++ b/dbms/src/Storages/MergeTree/IMergeTreeDataPart.cpp
@@ -227,7 +227,6 @@ void IMergeTreeDataPart::setColumns(const NamesAndTypesList & columns_)
     sample_block.clear();
     for (const auto & column : columns)
         sample_block.insert({column.type, column.name});
-    index_granularity_info.initialize(storage, getType(), columns.size());
 }
 
 IMergeTreeDataPart::~IMergeTreeDataPart() = default;
@@ -591,7 +590,7 @@ void IMergeTreeDataPart::loadColumns(bool require)
         columns.readText(file);
     }
 
-    index_granularity_info.initialize(storage, getType(), columns.size());
+    index_granularity_info = MergeTreeIndexGranularityInfo{storage, getType(), columns.size()};
     for (const auto & it : columns)
         sample_block.insert({it.type, it.name});
 }
diff --git a/dbms/src/Storages/MergeTree/MergeTreeData.cpp b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
index 79acbd5a683..0a628c3c692 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeData.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
@@ -1536,11 +1536,15 @@ MergeTreeData::MutableDataPartPtr MergeTreeData::createPart(
     const NamesAndTypesList & columns_list,
     size_t bytes_uncompressed,
     size_t rows_count,
-    const String & relative_path) const
+    const String & relative_path,
+    const MergeTreeIndexGranularityInfo * index_granularity_info) const
 {
-    auto part = createPart(name, choosePartType(bytes_uncompressed, rows_count), part_info, disk, relative_path);
+    auto type = choosePartType(bytes_uncompressed, rows_count);
+    auto part = createPart(name, type, part_info, disk, relative_path);
+    part->index_granularity_info = index_granularity_info ? *index_granularity_info
+        : MergeTreeIndexGranularityInfo{*this, type, columns_list.size()};
     part->setColumns(columns_list);
-    /// Don't save rows_count count here as it can change later
+    /// Don't save rows_count count here as it can be changed later
     return part;
 }
 
diff --git a/dbms/src/Storages/MergeTree/MergeTreeData.h b/dbms/src/Storages/MergeTree/MergeTreeData.h
index f413092c039..906f9e72859 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeData.h
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.h
@@ -187,7 +187,9 @@ public:
     MutableDataPartPtr createPart(const String & name,
         const MergeTreePartInfo & part_info,const DiskPtr & disk,
         const NamesAndTypesList & columns,
-        size_t bytes_on_disk, size_t rows_num, const String & relative_path) const;
+        size_t bytes_on_disk, size_t rows_num,
+        const String & relative_path,
+        const MergeTreeIndexGranularityInfo * index_granularity_info = nullptr) const;
 
     MutableDataPartPtr createPart(const String & name,
         MergeTreeDataPartType type, const MergeTreePartInfo & part_info,
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
index 496d8c00a1b..4a7bfa3883b 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
@@ -992,14 +992,12 @@ MergeTreeData::MutableDataPartPtr MergeTreeDataMergerMutator::mutatePartToTempor
         std::move(new_columns),
         source_part->bytes_on_disk,
         source_part->rows_count,
-        "tmp_mut_" + future_part.name);
+        "tmp_mut_" + future_part.name,
+        &source_part->index_granularity_info); /// Granularity info can't be changed during mutation.
 
     new_data_part->is_temp = true;
     new_data_part->ttl_infos = source_part->ttl_infos;
 
-    /// FIXME Now it's wrong code. Check if nothing will break
-    // new_data_part->index_granularity_info = source_part->index_granularity_info;
-
     String new_part_tmp_path = new_data_part->getFullPath();
 
     /// Note: this is done before creating input streams, because otherwise data.data_parts_mutex
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataPartCompact.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataPartCompact.cpp
index 0977d18b6f8..ede5ee474c4 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataPartCompact.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataPartCompact.cpp
@@ -160,7 +160,7 @@ String MergeTreeDataPartCompact::getColumnNameWithMinumumCompressedSize() const
 
 void MergeTreeDataPartCompact::loadIndexGranularity()
 {
-    index_granularity_info.initialize(storage, getType(), columns.size());
+    index_granularity_info = MergeTreeIndexGranularityInfo{storage, getType(), columns.size()};
     String full_path = getFullPath();
 
     if (columns.empty())
diff --git a/dbms/src/Storages/MergeTree/MergeTreeIndexGranularityInfo.cpp b/dbms/src/Storages/MergeTree/MergeTreeIndexGranularityInfo.cpp
index d441f10d753..d56c69b9173 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeIndexGranularityInfo.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeIndexGranularityInfo.cpp
@@ -33,14 +33,6 @@ std::optional<std::string> MergeTreeIndexGranularityInfo::getMrkExtensionFromFS(
 MergeTreeIndexGranularityInfo::MergeTreeIndexGranularityInfo(
     const MergeTreeData & storage, MergeTreeDataPartType part_type, size_t columns_num)
 {
-    initialize(storage, part_type, columns_num);
-}
-
-void MergeTreeIndexGranularityInfo::initialize(const MergeTreeData & storage, MergeTreeDataPartType part_type, size_t columns_num)
-{
-    if (initialized)
-        return;
-
     const auto storage_settings = storage.getSettings();
     fixed_index_granularity = storage_settings->index_granularity;
 
@@ -53,12 +45,12 @@ void MergeTreeIndexGranularityInfo::initialize(const MergeTreeData & storage, Me
     }
     else
         setAdaptive(storage_settings->index_granularity_bytes, part_type, columns_num);
-}
 
+    initialized = true;
+}
 
 void MergeTreeIndexGranularityInfo::changeGranularityIfRequired(const std::string & path_to_part)
 {
-    /// FIXME check when we cant create compact part
     auto mrk_ext = getMrkExtensionFromFS(path_to_part);
     if (mrk_ext && *mrk_ext == getNonAdaptiveMrkExtension())
         setNonAdaptive();
diff --git a/dbms/src/Storages/MergeTree/MergedBlockOutputStream.cpp b/dbms/src/Storages/MergeTree/MergedBlockOutputStream.cpp
index 7059f67148b..f3541d5a351 100644
--- a/dbms/src/Storages/MergeTree/MergedBlockOutputStream.cpp
+++ b/dbms/src/Storages/MergeTree/MergedBlockOutputStream.cpp
@@ -162,7 +162,6 @@ void MergedBlockOutputStream::writeSuffixAndFinalizePart(
 
     new_part->rows_count = rows_count;
     new_part->modification_time = time(nullptr);
-    // new_part->setColumns(*total_column_list);
     new_part->index = writer->releaseIndexColumns();
     new_part->checksums = checksums;
     new_part->bytes_on_disk = checksums.getTotalSizeOnDisk();