ClickHouse/dbms/include/DB/Storages/MergeTree/LevelMergeSelector.h

#pragma once

#include <DB/Storages/MergeTree/MergeSelector.h>


namespace DB
{

/** Select parts to merge based on its level.
  * Select first range of parts of parts_to_merge length with minimum level.
  */
class LevelMergeSelector : public IMergeSelector
{
public:
	struct Settings
	{
		size_t parts_to_merge = 10;
	};

	LevelMergeSelector(const Settings & settings) : settings(settings) {}

	PartsInPartition select(
		const Partitions & partitions,
		const size_t max_total_size_to_merge) override;

private:
	const Settings settings;
};

}