ClickHouse/dbms/include/DB/Storages/StorageSystemDatabases.h

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#pragma once
#include <Poco/SharedPtr.h>
#include <DB/Storages/IStorage.h>
#include <DB/Interpreters/Context.h>
namespace DB
{
using Poco::SharedPtr;
/** Реализует системную таблицу databases, которая позволяет получить информацию о всех БД.
*/
class StorageSystemDatabases : public IStorage
{
public:
static StoragePtr create(const std::string & name_);
std::string getName() const override { return "SystemDatabases"; }
std::string getTableName() const override { return name; }
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const NamesAndTypesList & getColumnsListImpl() const override { return columns; }
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BlockInputStreams read(
const Names & column_names,
ASTPtr query,
const Context & context,
const Settings & settings,
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QueryProcessingStage::Enum & processed_stage,
size_t max_block_size = DEFAULT_BLOCK_SIZE,
unsigned threads = 1) override;
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private:
const std::string name;
NamesAndTypesList columns;
StorageSystemDatabases(const std::string & name_);
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};
}