From 71233e11a9d6daf10cbcc1aa1638b152b647d816 Mon Sep 17 00:00:00 2001
From: Amos Bird <amosbird@gmail.com>
Date: Wed, 17 Jul 2019 09:24:37 +0800
Subject: [PATCH] minor updates.

---
 dbms/src/Columns/IColumn.h                      | 14 --------------
 dbms/src/Storages/IStorage.h                    | 15 +++++++++++++++
 dbms/src/Storages/MergeTree/MergeTreeDataPart.h |  1 +
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/dbms/src/Columns/IColumn.h b/dbms/src/Columns/IColumn.h
index 17c62fbd2d8..3955ed4b528 100644
--- a/dbms/src/Columns/IColumn.h
+++ b/dbms/src/Columns/IColumn.h
@@ -24,20 +24,6 @@ namespace ErrorCodes
 class Arena;
 class ColumnGathererStream;
 
-struct ColumnSize
-{
-    size_t marks = 0;
-    size_t data_compressed = 0;
-    size_t data_uncompressed = 0;
-
-    void add(const ColumnSize & other)
-    {
-        marks += other.marks;
-        data_compressed += other.data_compressed;
-        data_uncompressed += other.data_uncompressed;
-    }
-};
-
 /// Declares interface to store columns in memory.
 class IColumn : public COW<IColumn>
 {
diff --git a/dbms/src/Storages/IStorage.h b/dbms/src/Storages/IStorage.h
index 7c45401e338..477c4456b17 100644
--- a/dbms/src/Storages/IStorage.h
+++ b/dbms/src/Storages/IStorage.h
@@ -38,6 +38,19 @@ class AlterCommands;
 class MutationCommands;
 class PartitionCommands;
 
+struct ColumnSize
+{
+    size_t marks = 0;
+    size_t data_compressed = 0;
+    size_t data_uncompressed = 0;
+
+    void add(const ColumnSize & other)
+    {
+        marks += other.marks;
+        data_compressed += other.data_compressed;
+        data_uncompressed += other.data_uncompressed;
+    }
+};
 
 /** Storage. Describes the table. Responsible for
   * - storage of the table data;
@@ -82,6 +95,8 @@ public:
     /// Returns true if the storage supports deduplication of inserted data blocks.
     virtual bool supportsDeduplication() const { return false; }
 
+    /// Optional size information of each physical column.
+    /// Currently it's only used by the MergeTree family for query optimizations.
     using ColumnSizeByName = std::unordered_map<std::string, ColumnSize>;
     virtual ColumnSizeByName getColumnSizes() const { return {}; }
 
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataPart.h b/dbms/src/Storages/MergeTree/MergeTreeDataPart.h
index 053e9428861..f41ea8af424 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataPart.h
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataPart.h
@@ -22,6 +22,7 @@
 namespace DB
 {
 
+struct ColumnSize;
 class MergeTreeData;