ClickHouse/dbms/include/DB/Storages/System/StorageSystemProcesses.h

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#pragma once
#include <ext/shared_ptr_helper.hpp>
#include <DB/Storages/IStorage.h>
namespace DB
{
2016-12-08 02:49:04 +00:00
class Context;
/** Реализует системную таблицу processes, которая позволяет получить информацию о запросах, исполняющихся в данный момент.
*/
class StorageSystemProcesses : private ext::shared_ptr_helper<StorageSystemProcesses>, public IStorage
{
friend class ext::shared_ptr_helper<StorageSystemProcesses>;
public:
static StoragePtr create(const std::string & name_);
std::string getName() const override { return "SystemProcesses"; }
std::string getTableName() const override { return name; }
const NamesAndTypesList & getColumnsListImpl() const override { return columns; }
BlockInputStreams read(
const Names & column_names,
ASTPtr query,
const Context & context,
const Settings & settings,
QueryProcessingStage::Enum & processed_stage,
size_t max_block_size = DEFAULT_BLOCK_SIZE,
unsigned threads = 1) override;
private:
const std::string name;
NamesAndTypesList columns;
StorageSystemProcesses(const std::string & name_);
};
}