#pragma once #include namespace DB { class Context; /** Implements system table 'clusters' * that allows to obtain information about available clusters * (which may be specified in Distributed tables). */ class StorageSystemClusters : public IStorage { public: StorageSystemClusters(const std::string & name_, Context & context_); static StoragePtr create(const std::string & name_, Context & context_); std::string getName() const override { return "SystemClusters"; } 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: StorageSystemClusters(const std::string & name_); private: const std::string name; NamesAndTypesList columns; Context & context; }; }