GraphiteMergeTree: fixed handling of 'version' column [#CLICKHOUSE-2804].

dbms/include/DB/DataStreams/GraphiteRollupSortedBlockInputStream.h

@@ -179,15 +179,16 @@ private:
 	/// All data has been read.
 	bool finished = false;
 
-	/// This object owns a column while 'current_path' references to it.
-	SharedBlockPtr owned_current_block;
+	RowRef selected_row;		/// Last row with maximum version for current primary key.
+	UInt64 current_max_version = 0;
 
 	bool is_first = true;
 	StringRef current_path;
-	time_t current_time;
+	time_t current_time = 0;
+	time_t current_time_rounded = 0;
 	StringRef next_path;
-	time_t next_time;
-	UInt64 current_max_version = 0;
+	time_t next_time = 0;
+	time_t next_time_rounded = 0;
 
 	const Graphite::Pattern * current_pattern = nullptr;
 	std::vector<char> place_for_aggregate_state;
@@ -207,8 +208,7 @@ private:
 	void finishCurrentRow(ColumnPlainPtrs & merged_columns);
 
 	/// Обновить состояние агрегатной функции новым значением value.
-	template <class TSortCursor>
-	void accumulateRow(TSortCursor & cursor);
+	void accumulateRow(RowRef & row);
 };
 
 }

dbms/include/DB/DataStreams/ReplacingSortedBlockInputStream.h

@@ -51,15 +51,15 @@ private:
 
 	Logger * log = &Logger::get("ReplacingSortedBlockInputStream");
 
-	/// Прочитали до конца.
+	/// All data has been read.
 	bool finished = false;
 
-	RowRef current_key;			/// Текущий первичный ключ.
-	RowRef next_key;			/// Первичный ключ следующей строки.
+	RowRef current_key;			/// Primary key of current row.
+	RowRef next_key;			/// Primary key of next row.
 
-	RowRef selected_row;		/// Последняя строка с максимальной версией для текущего первичного ключа.
+	RowRef selected_row;		/// Last row with maximum version for current primary key.
 
-	UInt64 max_version = 0;		/// Максимальная версия для текущего первичного ключа.
+	UInt64 max_version = 0;		/// Max version for current primary key.
 
 	template<class TSortCursor>
 	void merge(ColumnPlainPtrs & merged_columns, std::priority_queue<TSortCursor> & queue);

dbms/src/DataStreams/GraphiteRollupSortedBlockInputStream.cpp

@@ -93,6 +93,9 @@ Block GraphiteRollupSortedBlockInputStream::readImpl()
 		for (size_t i = 0; i < num_columns; ++i)
 			if (i != time_column_num && i != value_column_num && i != version_column_num)
 				unmodified_column_numbers.push_back(i);
+
+		if (selected_row.empty())
+			selected_row.columns.resize(num_columns);
 	}
 
 	if (has_collation)
@@ -123,19 +126,29 @@ void GraphiteRollupSortedBlockInputStream::merge(ColumnPlainPtrs & merged_column
 		bool path_differs = is_first || next_path != current_path;
 		is_first = false;
 
+		/// Is new key before rounding.
+		bool is_new_key = path_differs || next_time != current_time;
+
+		UInt64 current_version = current->all_columns[version_column_num]->get64(current->pos);
+
+		if (is_new_key)
+		{
+			current_max_version = 0;
+
 			if (path_differs)
 				current_pattern = selectPatternForPath(next_path);
 
 			if (current_pattern)
 			{
 				UInt32 precision = selectPrecision(current_pattern->retentions, next_time);
-			next_time = roundTimeToPrecision(date_lut, next_time, precision);
+				next_time_rounded = roundTimeToPrecision(date_lut, next_time, precision);
 			}
 			/// If no patterns has matched - it means that no need to do rounding.
 
-		bool is_new_key = path_differs || next_time != current_time;
+			/// Key will be new after rounding.
+			bool will_be_new_key = path_differs || next_time_rounded != current_time_rounded;
 
-		if (is_new_key)
+			if (will_be_new_key)
 			{
 				if (merged_rows)
 				{
@@ -148,10 +161,9 @@ void GraphiteRollupSortedBlockInputStream::merge(ColumnPlainPtrs & merged_column
 
 				startNextRow(merged_columns, current);
 
-			owned_current_block = source_blocks[current.impl->order];
 				current_path = next_path;
 				current_time = next_time;
-			current_max_version = 0;
+				current_time_rounded = next_time_rounded;
 
 				if (prev_pattern)
 					prev_pattern->function->destroy(place_for_aggregate_state.data());
@@ -161,8 +173,16 @@ void GraphiteRollupSortedBlockInputStream::merge(ColumnPlainPtrs & merged_column
 				++merged_rows;
 			}
 
-		accumulateRow(current);
-		current_max_version = std::max(current_max_version, current->all_columns[version_column_num]->get64(current->pos));
+			accumulateRow(selected_row);
+			current_max_version = current_version;
+		}
+		else if (current_version >= current_max_version)
+		{
+			/// Within all rows with same key, we should leave only one row with maximum version;
+			///  and for rows with same maximum version - only last row.
+			current_max_version = current_version;
+			setRowRef(selected_row, current);
+		}
 
 		queue.pop();
 
@@ -210,7 +230,7 @@ void GraphiteRollupSortedBlockInputStream::startNextRow(ColumnPlainPtrs & merged
 void GraphiteRollupSortedBlockInputStream::finishCurrentRow(ColumnPlainPtrs & merged_columns)
 {
 	/// Вставляем вычисленные значения столбцов time, value, version.
-	merged_columns[time_column_num]->insert(UInt64(current_time));
+	merged_columns[time_column_num]->insert(UInt64(current_time_rounded));
 	merged_columns[version_column_num]->insert(current_max_version);
 
 	if (current_pattern)
@@ -218,11 +238,10 @@ void GraphiteRollupSortedBlockInputStream::finishCurrentRow(ColumnPlainPtrs & me
 }
 
 
-template <class TSortCursor>
-void GraphiteRollupSortedBlockInputStream::accumulateRow(TSortCursor & cursor)
+void GraphiteRollupSortedBlockInputStream::accumulateRow(RowRef & row)
 {
 	if (current_pattern)
-		current_pattern->function->add(place_for_aggregate_state.data(), &cursor->all_columns[value_column_num], cursor->pos, nullptr);
+		current_pattern->function->add(place_for_aggregate_state.data(), &row.columns[value_column_num], row.row_num, nullptr);
 }
 
 }

dbms/src/DataStreams/ReplacingSortedBlockInputStream.cpp

@@ -29,7 +29,7 @@ Block ReplacingSortedBlockInputStream::readImpl()
 	if (merged_columns.empty())
 		return Block();
 
-	/// Дополнительная инициализация.
+	/// Additional initialization.
 	if (selected_row.empty())
 	{
 		selected_row.columns.resize(num_columns);