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

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#pragma once
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#include <ext/shared_ptr_helper.hpp>
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#include <DB/Storages/IStorage.h>
namespace DB
{
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class Context;
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/** Реализует хранилище для системной таблицы Numbers.
* Таблица содержит единственный столбец number UInt64.
* Из этой таблицы можно прочитать все натуральные числа, начиная с 0 (до 2^64 - 1, а потом заново).
*/
class StorageSystemNumbers : private ext::shared_ptr_helper<StorageSystemNumbers>, public IStorage
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{
friend class ext::shared_ptr_helper<StorageSystemNumbers>;
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public:
static StoragePtr create(const std::string & name_, bool multithreaded_ = false);
std::string getName() const override { return "SystemNumbers"; }
std::string getTableName() const override { return name; }
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const NamesAndTypesList & getColumnsListImpl() const override { return columns; }
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BlockInputStreams read(
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const Names & column_names,
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ASTPtr query,
const Context & context,
const Settings & settings,
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QueryProcessingStage::Enum & processed_stage,
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size_t max_block_size = DEFAULT_BLOCK_SIZE,
unsigned threads = 1) override;
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private:
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const std::string name;
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NamesAndTypesList columns;
bool multithreaded;
StorageSystemNumbers(const std::string & name_, bool multithreaded_);
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};
}