ClickHouse/src/Interpreters/join_common.h

82 lines
3.3 KiB
C++

#pragma once
#include <Core/Block.h>
#include <Interpreters/IJoin.h>
#include <Interpreters/ActionsDAG.h>
#include <Interpreters/ExpressionActions.h>
namespace DB
{
struct ColumnWithTypeAndName;
class TableJoin;
class IColumn;
using ColumnRawPtrs = std::vector<const IColumn *>;
namespace JoinCommon
{
bool canBecomeNullable(const DataTypePtr & type);
DataTypePtr convertTypeToNullable(const DataTypePtr & type);
void convertColumnToNullable(ColumnWithTypeAndName & column, bool remove_low_card = false);
void convertColumnsToNullable(Block & block, size_t starting_pos = 0);
void removeColumnNullability(ColumnWithTypeAndName & column);
void changeColumnRepresentation(const ColumnPtr & src_column, ColumnPtr & dst_column);
ColumnPtr emptyNotNullableClone(const ColumnPtr & column);
Columns materializeColumns(const Block & block, const Names & names);
ColumnRawPtrs materializeColumnsInplace(Block & block, const Names & names);
ColumnRawPtrs getRawPointers(const Columns & columns);
void removeLowCardinalityInplace(Block & block);
void removeLowCardinalityInplace(Block & block, const Names & names, bool change_type = true);
void restoreLowCardinalityInplace(Block & block);
ColumnRawPtrs extractKeysForJoin(const Block & block_keys, const Names & key_names_right);
/// Throw an exception if blocks have different types of key columns. Compare up to Nullability.
void checkTypesOfKeys(const Block & block_left, const Names & key_names_left, const Block & block_right, const Names & key_names_right);
void createMissedColumns(Block & block);
void joinTotals(const Block & totals, const Block & columns_to_add, const TableJoin & table_join, Block & block);
void addDefaultValues(IColumn & column, const DataTypePtr & type, size_t count);
bool typesEqualUpToNullability(DataTypePtr left_type, DataTypePtr right_type);
}
/// Creates result from right table data in RIGHT and FULL JOIN when keys are not present in left table.
class NotJoined
{
public:
NotJoined(const TableJoin & table_join, const Block & saved_block_sample_, const Block & right_sample_block,
const Block & result_sample_block_);
void correctLowcardAndNullability(MutableColumns & columns_right);
void addLeftColumns(Block & block, size_t rows_added) const;
void addRightColumns(Block & block, MutableColumns & columns_right) const;
void copySameKeys(Block & block) const;
protected:
Block saved_block_sample;
Block result_sample_block;
~NotJoined() = default;
private:
/// Indices of columns in result_sample_block that should be generated
std::vector<size_t> column_indices_left;
/// Indices of columns that come from the right-side table: right_pos -> result_pos
std::unordered_map<size_t, size_t> column_indices_right;
///
std::unordered_map<size_t, size_t> same_result_keys;
/// Which right columns (saved in parent) need nullability change before placing them in result block
std::vector<size_t> right_nullability_adds;
std::vector<size_t> right_nullability_removes;
/// Which right columns (saved in parent) need LowCardinality change before placing them in result block
std::vector<std::pair<size_t, ColumnPtr>> right_lowcard_changes;
void setRightIndex(size_t right_pos, size_t result_position);
void extractColumnChanges(size_t right_pos, size_t result_pos);
};
}