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42 lines
1.0 KiB
C++
42 lines
1.0 KiB
C++
#pragma once
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#include <ext/shared_ptr_helper.hpp>
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#include <DB/Storages/IStorage.h>
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namespace DB
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{
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class Context;
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/** Implements system table 'columns', that allows to get information about columns for every table.
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*/
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class StorageSystemColumns : private ext::shared_ptr_helper<StorageSystemColumns>, public IStorage
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{
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friend class ext::shared_ptr_helper<StorageSystemColumns>;
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public:
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static StoragePtr create(const std::string & name_);
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std::string getName() const override { return "SystemColumns"; }
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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,
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const Context & context,
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const Settings & settings,
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QueryProcessingStage::Enum & processed_stage,
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size_t max_block_size = DEFAULT_BLOCK_SIZE,
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unsigned threads = 1) override;
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private:
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StorageSystemColumns(const std::string & name_);
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private:
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const std::string name;
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NamesAndTypesList columns;
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};
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}
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