Review comments

Author: Deepak Majeti

src/parquet/column_writer.cc

@@ -267,9 +267,10 @@ int64_t ColumnWriter::Close() {
     FlushBufferedDataPages();
 
     EncodedStatistics chunk_statistics = GetChunkStatistics();
-    if (chunk_statistics.is_set())
+    if (chunk_statistics.is_set()) {
       metadata_->SetStatistics(SortOrder::SIGNED == descr_->sort_order(),
                                chunk_statistics);
+    }
     pager_->Close(has_dictionary_, fallback_);
   }
 

src/parquet/file/metadata.h

@@ -82,7 +82,7 @@ class ApplicationVersion {
   bool VersionEq(const ApplicationVersion& other_version) const;
 
   // Checks if the Version has the correct statistics for a given column
-  bool HasCorrectStatistics(Type::type primitive, SortOrder::type sort_order) const;
+  bool HasCorrectStatistics(Type::type primitive, SortOrder::type sort_order = SortOrder::SIGNED) const;
 };
 
 class PARQUET_EXPORT ColumnChunkMetaData {

src/parquet/types.h

@@ -296,9 +296,9 @@ PARQUET_EXPORT std::string FormatStatValue(Type::type parquet_type, const char*
 
 PARQUET_EXPORT int GetTypeByteSize(Type::type t);
 
-SortOrder::type PARQUET_EXPORT DefaultSortOrder(Type::type primitive);
+PARQUET_EXPORT SortOrder::type DefaultSortOrder(Type::type primitive);
 
-SortOrder::type PARQUET_EXPORT GetSortOrder(LogicalType::type converted,
+PARQUET_EXPORT SortOrder::type GetSortOrder(LogicalType::type converted,
                                             Type::type primitive);
 
 }  // namespace parquet