ClickHouse/src/Interpreters/PasteJoin.h
2024-01-25 14:31:49 +03:00

97 lines
3.1 KiB
C++

#pragma once
#include <Interpreters/IJoin.h>
#include <Interpreters/TableJoin.h>
#include <DataTypes/DataTypeNullable.h>
#include <DataTypes/DataTypeLowCardinality.h>
#include <Common/logger_useful.h>
#include <Poco/Logger.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int NOT_IMPLEMENTED;
}
/// Dummy class, actual joining is done by MergeTransform
class PasteJoin : public IJoin
{
public:
explicit PasteJoin(std::shared_ptr<TableJoin> table_join_, const Block & right_sample_block_)
: table_join(table_join_)
, right_sample_block(right_sample_block_)
{
LOG_TRACE(getLogger("PasteJoin"), "Will use paste join");
}
std::string getName() const override { return "PasteJoin"; }
const TableJoin & getTableJoin() const override { return *table_join; }
bool addBlockToJoin(const Block & /* block */, bool /* check_limits */) override
{
throw Exception(ErrorCodes::LOGICAL_ERROR, "PasteJoin::addBlockToJoin should not be called");
}
static bool isSupported(const std::shared_ptr<TableJoin> & table_join)
{
bool support_storage = !table_join->isSpecialStorage();
/// Key column can change nullability and it's not handled on type conversion stage, so algorithm should be aware of it
bool support_using = !table_join->hasUsing();
bool check_strictness = table_join->strictness() == JoinStrictness::All;
bool if_has_keys = table_join->getClauses().empty();
return support_using && support_storage && check_strictness && if_has_keys;
}
void checkTypesOfKeys(const Block & /*left_block*/) const override
{
if (!isSupported(table_join))
throw DB::Exception(ErrorCodes::NOT_IMPLEMENTED, "PasteJoin doesn't support specified query");
}
/// Used just to get result header
void joinBlock(Block & block, std::shared_ptr<ExtraBlock> & /* not_processed */) override
{
for (const auto & col : right_sample_block)
block.insert(col);
block = materializeBlock(block).cloneEmpty();
}
void setTotals(const Block & block) override { totals = block; }
const Block & getTotals() const override { return totals; }
size_t getTotalRowCount() const override
{
throw Exception(ErrorCodes::LOGICAL_ERROR, "PasteJoin::getTotalRowCount should not be called");
}
size_t getTotalByteCount() const override
{
throw Exception(ErrorCodes::LOGICAL_ERROR, "PasteJoin::getTotalByteCount should not be called");
}
bool alwaysReturnsEmptySet() const override { return false; }
IBlocksStreamPtr
getNonJoinedBlocks(const Block & /* left_sample_block */, const Block & /* result_sample_block */, UInt64 /* max_block_size */) const override
{
throw Exception(ErrorCodes::LOGICAL_ERROR, "PasteJoin::getNonJoinedBlocks should not be called");
}
/// Left and right streams have the same priority and are processed simultaneously
JoinPipelineType pipelineType() const override { return JoinPipelineType::YShaped; }
private:
std::shared_ptr<TableJoin> table_join;
Block right_sample_block;
Block totals;
};
}