diff --git a/dbms/src/Storages/MergeTree/MergeTreeData.cpp b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
index 7d6b4905b03..79e34b9bf4c 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeData.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
@@ -1206,7 +1206,7 @@ void MergeTreeData::createConvertExpression(const DataPartPtr & part, const Name
         if (!new_types.count(column.name))
         {
             /// The column was deleted.
-            if (!part || part->hasColumnFiles(column.name))
+            if (part && part->hasColumnFiles(column.name))
             {
                 column.type->enumerateStreams([&](const IDataType::SubstreamPath & substream_path)
                 {
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
index 9415a2c9175..3f550a1034f 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
@@ -1046,7 +1046,7 @@ MergeTreeDataMergerMutator::MergeAlgorithm MergeTreeDataMergerMutator::chooseMer
     const NamesAndTypesList & gathering_columns, bool deduplicate) const
 {
     /// TODO(alesap) remove me
-    return MergeAlgorithm::Vertical;
+    ///return MergeAlgorithm::Vertical;
     if (deduplicate)
         return MergeAlgorithm::Horizontal;
     if (data.settings.enable_vertical_merge_algorithm == 0)