ClickHouse/src/Storages/StorageValues.h
2020-04-29 15:15:23 +03:00

43 lines
1.2 KiB
C++

#pragma once
#include <ext/shared_ptr_helper.h>
#include <Storages/IStorage.h>
namespace DB
{
/* One block storage used for values table function
* It's structure is similar to IStorageSystemOneBlock
*/
class StorageValues final : public ext::shared_ptr_helper<StorageValues>, public IStorage
{
friend struct ext::shared_ptr_helper<StorageValues>;
public:
std::string getName() const override { return "Values"; }
Pipes read(
const Names & column_names,
const SelectQueryInfo & query_info,
const Context & context,
QueryProcessingStage::Enum processed_stage,
size_t max_block_size,
unsigned num_streams) override;
/// Why we may have virtual columns in the storage from a single block?
/// Because it used as tmp storage for pushing blocks into views, and some
/// views may contain virtual columns from original storage.
NamesAndTypesList getVirtuals() const override
{
return virtuals;
}
private:
Block res_block;
NamesAndTypesList virtuals;
protected:
StorageValues(
const StorageID & table_id_, const ColumnsDescription & columns_, const Block & res_block_, const NamesAndTypesList & virtuals_ = {});
};
}