Fix style

src/Storages/MergeTree/MergeTreeData.cpp

@@ -7522,7 +7522,7 @@ bool MergeTreeData::canUsePolymorphicParts(const MergeTreeSettings & settings, S
 
 AlterConversions MergeTreeData::getAlterConversionsForPart(const MergeTreeDataPartPtr part) const
 {
-    MutationCommands commands = getFirstAlterMutationCommandsForPart(part);
+    MutationCommands commands = getAlterMutationCommandsForPart(part);
 
     AlterConversions result{};
     for (const auto & command : commands)

src/Storages/MergeTree/MergeTreeData.h

@@ -1303,7 +1303,7 @@ protected:
     /// Used to receive AlterConversions for part and apply them on fly. This
     /// method has different implementations for replicated and non replicated
     /// MergeTree because they store mutations in different way.
-    virtual MutationCommands getFirstAlterMutationCommandsForPart(const DataPartPtr & part) const = 0;
+    virtual MutationCommands getAlterMutationCommandsForPart(const DataPartPtr & part) const = 0;
     /// Moves part to specified space, used in ALTER ... MOVE ... queries
     bool movePartsToSpace(const DataPartsVector & parts, SpacePtr space);
 

src/Storages/MergeTree/MutateTask.cpp

@@ -170,11 +170,7 @@ static void splitMutationCommands(
             if (alter_conversions.columnHasNewName(part_column.name))
             {
                 auto new_column_name = alter_conversions.getColumnNewName(part_column.name);
-                for_file_renames.push_back({
-                    .type = MutationCommand::Type::RENAME_COLUMN,
-                    .column_name = part_column.name,
-                    .rename_to = new_column_name,
-                });
+                for_file_renames.push_back({.type = MutationCommand::Type::RENAME_COLUMN, .column_name = part_column.name, .rename_to = new_column_name});
 
                 part_columns.rename(part_column.name, new_column_name);
             }

src/Storages/MergeTree/ReplicatedMergeTreeQueue.cpp

@@ -1752,7 +1752,7 @@ ReplicatedMergeTreeMergePredicate ReplicatedMergeTreeQueue::getMergePredicate(zk
 }
 
 
-MutationCommands ReplicatedMergeTreeQueue::getFirstAlterMutationCommandsForPart(const MergeTreeData::DataPartPtr & part) const
+MutationCommands ReplicatedMergeTreeQueue::getAlterMutationCommandsForPart(const MergeTreeData::DataPartPtr & part) const
 {
     std::lock_guard lock(state_mutex);
     auto in_partition = mutations_by_partition.find(part->info.partition_id);
@@ -1761,6 +1761,10 @@ MutationCommands ReplicatedMergeTreeQueue::getFirstAlterMutationCommandsForPart(
 
     Int64 part_mutation_version = part->info.getMutationVersion();
     MutationCommands result;
+    /// Here we return mutation commands for part which has bigger mutation version than part mutation version.
+    /// Please note, we don't use getDataVersion(). It's because these alter commands are used for in-fly conversions
+    /// of part's metadata. It mean that even if we have mutation with version X and part with data version X+10, but
+    /// without mutation version part can still have wrong metadata and we have to apply this change on-fly if needed.
     for (auto [mutation_version, mutation_status] : in_partition->second)
     {
         if (mutation_version > part_mutation_version && mutation_status->entry->alter_version != -1)

src/Storages/MergeTree/ReplicatedMergeTreeQueue.h

@@ -393,10 +393,10 @@ public:
 
     MutationCommands getMutationCommands(const MergeTreeData::DataPartPtr & part, Int64 desired_mutation_version) const;
 
-    /// Return mutation commands for part with smallest mutation version bigger
-    /// than data part version. Used when we apply alter commands on fly,
+    /// Return mutation commands for part which could be not applied to
+    /// it according to part mutation version. Used when we apply alter commands on fly,
     /// without actual data modification on disk.
-    MutationCommands getFirstAlterMutationCommandsForPart(const MergeTreeData::DataPartPtr & part) const;
+    MutationCommands getAlterMutationCommandsForPart(const MergeTreeData::DataPartPtr & part) const;
 
     /// Mark finished mutations as done. If the function needs to be called again at some later time
     /// (because some mutations are probably done but we are not sure yet), returns true.

src/Storages/StorageMergeTree.cpp

@@ -2056,7 +2056,7 @@ void StorageMergeTree::attachRestoredParts(MutableDataPartsVector && parts)
 }
 
 
-MutationCommands StorageMergeTree::getFirstAlterMutationCommandsForPart(const DataPartPtr & part) const
+MutationCommands StorageMergeTree::getAlterMutationCommandsForPart(const DataPartPtr & part) const
 {
     std::lock_guard lock(currently_processing_in_background_mutex);
 

src/Storages/StorageMergeTree.h

@@ -265,7 +265,7 @@ private:
 
 protected:
 
-    MutationCommands getFirstAlterMutationCommandsForPart(const DataPartPtr & part) const override;
+    MutationCommands getAlterMutationCommandsForPart(const DataPartPtr & part) const override;
 };
 
 }

src/Storages/StorageReplicatedMergeTree.cpp

@@ -7892,9 +7892,9 @@ bool StorageReplicatedMergeTree::canUseAdaptiveGranularity() const
 }
 
 
-MutationCommands StorageReplicatedMergeTree::getFirstAlterMutationCommandsForPart(const DataPartPtr & part) const
+MutationCommands StorageReplicatedMergeTree::getAlterMutationCommandsForPart(const DataPartPtr & part) const
 {
-    return queue.getFirstAlterMutationCommandsForPart(part);
+    return queue.getAlterMutationCommandsForPart(part);
 }
 
 

src/Storages/StorageReplicatedMergeTree.h

@@ -830,7 +830,7 @@ private:
     void waitMutationToFinishOnReplicas(
         const Strings & replicas, const String & mutation_id) const;
 
-    MutationCommands getFirstAlterMutationCommandsForPart(const DataPartPtr & part) const override;
+    MutationCommands getAlterMutationCommandsForPart(const DataPartPtr & part) const override;
 
     void startBackgroundMovesIfNeeded() override;