mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-29 02:52:13 +00:00
431 lines
17 KiB
C++
431 lines
17 KiB
C++
#pragma once
|
||
|
||
#include <variant>
|
||
#include <optional>
|
||
#include <shared_mutex>
|
||
#include <deque>
|
||
#include <vector>
|
||
|
||
#include <Parsers/ASTTablesInSelectQuery.h>
|
||
|
||
#include <Interpreters/IJoin.h>
|
||
#include <Interpreters/AggregationCommon.h>
|
||
#include <Interpreters/RowRefs.h>
|
||
|
||
#include <Common/Arena.h>
|
||
#include <Common/ColumnsHashing.h>
|
||
#include <Common/HashTable/HashMap.h>
|
||
#include <Common/HashTable/FixedHashMap.h>
|
||
#include <Storages/TableLockHolder.h>
|
||
#include <Common/logger_useful.h>
|
||
|
||
#include <Columns/ColumnString.h>
|
||
#include <Columns/ColumnFixedString.h>
|
||
|
||
#include <QueryPipeline/SizeLimits.h>
|
||
|
||
#include <Core/Block.h>
|
||
|
||
#include <Storages/IStorage_fwd.h>
|
||
#include <Storages/IKVStorage.h>
|
||
|
||
namespace DB
|
||
{
|
||
|
||
class TableJoin;
|
||
class DictionaryReader;
|
||
|
||
namespace JoinStuff
|
||
{
|
||
|
||
/// Flags needed to implement RIGHT and FULL JOINs.
|
||
class JoinUsedFlags
|
||
{
|
||
using RawBlockPtr = const Block *;
|
||
using UsedFlagsForBlock = std::vector<std::atomic_bool>;
|
||
|
||
/// For multiple dijuncts each empty in hashmap stores flags for particular block
|
||
/// For single dicunct we store all flags in `nullptr` entry, index is the offset in FindResult
|
||
std::unordered_map<RawBlockPtr, UsedFlagsForBlock> flags;
|
||
|
||
bool need_flags;
|
||
|
||
public:
|
||
/// Update size for vector with flags.
|
||
/// Calling this method invalidates existing flags.
|
||
/// It can be called several times, but all of them should happen before using this structure.
|
||
template <ASTTableJoin::Kind KIND, ASTTableJoin::Strictness STRICTNESS>
|
||
void reinit(size_t size_);
|
||
|
||
template <ASTTableJoin::Kind KIND, ASTTableJoin::Strictness STRICTNESS>
|
||
void reinit(const Block * block_ptr);
|
||
|
||
bool getUsedSafe(size_t i) const;
|
||
bool getUsedSafe(const Block * block_ptr, size_t row_idx) const;
|
||
|
||
template <bool use_flags, bool multiple_disjuncts, typename T>
|
||
void setUsed(const T & f);
|
||
|
||
template <bool use_flags, bool multiple_disjunct>
|
||
void setUsed(const Block * block, size_t row_num, size_t offset);
|
||
|
||
template <bool use_flags, bool multiple_disjuncts, typename T>
|
||
bool getUsed(const T & f);
|
||
|
||
template <bool use_flags, bool multiple_disjuncts, typename T>
|
||
bool setUsedOnce(const T & f);
|
||
};
|
||
|
||
}
|
||
|
||
/** Data structure for implementation of JOIN.
|
||
* It is just a hash table: keys -> rows of joined ("right") table.
|
||
* Additionally, CROSS JOIN is supported: instead of hash table, it use just set of blocks without keys.
|
||
*
|
||
* JOIN-s could be of these types:
|
||
* - ALL × LEFT/INNER/RIGHT/FULL
|
||
* - ANY × LEFT/INNER/RIGHT
|
||
* - SEMI/ANTI x LEFT/RIGHT
|
||
* - ASOF x LEFT/INNER
|
||
* - CROSS
|
||
*
|
||
* ALL means usual JOIN, when rows are multiplied by number of matching rows from the "right" table.
|
||
* ANY uses one line per unique key from right table. For LEFT JOIN it would be any row (with needed joined key) from the right table,
|
||
* for RIGHT JOIN it would be any row from the left table and for INNER one it would be any row from right and any row from left.
|
||
* SEMI JOIN filter left table by keys that are present in right table for LEFT JOIN, and filter right table by keys from left table
|
||
* for RIGHT JOIN. In other words SEMI JOIN returns only rows which joining keys present in another table.
|
||
* ANTI JOIN is the same as SEMI JOIN but returns rows with joining keys that are NOT present in another table.
|
||
* SEMI/ANTI JOINs allow to get values from both tables. For filter table it gets any row with joining same key. For ANTI JOIN it returns
|
||
* defaults other table columns.
|
||
* ASOF JOIN is not-equi join. For one key column it finds nearest value to join according to join inequality.
|
||
* It's expected that ANY|SEMI LEFT JOIN is more efficient that ALL one.
|
||
*
|
||
* If INNER is specified - leave only rows that have matching rows from "right" table.
|
||
* If LEFT is specified - in case when there is no matching row in "right" table, fill it with default values instead.
|
||
* If RIGHT is specified - first process as INNER, but track what rows from the right table was joined,
|
||
* and at the end, add rows from right table that was not joined and substitute default values for columns of left table.
|
||
* If FULL is specified - first process as LEFT, but track what rows from the right table was joined,
|
||
* and at the end, add rows from right table that was not joined and substitute default values for columns of left table.
|
||
*
|
||
* Thus, LEFT and RIGHT JOINs are not symmetric in terms of implementation.
|
||
*
|
||
* All JOINs (except CROSS) are done by equality condition on keys (equijoin).
|
||
* Non-equality and other conditions are not supported.
|
||
*
|
||
* Implementation:
|
||
*
|
||
* 1. Build hash table in memory from "right" table.
|
||
* This hash table is in form of keys -> row in case of ANY or keys -> [rows...] in case of ALL.
|
||
* This is done in insertFromBlock method.
|
||
*
|
||
* 2. Process "left" table and join corresponding rows from "right" table by lookups in the map.
|
||
* This is done in joinBlock methods.
|
||
*
|
||
* In case of ANY LEFT JOIN - form new columns with found values or default values.
|
||
* This is the most simple. Number of rows in left table does not change.
|
||
*
|
||
* In case of ANY INNER JOIN - form new columns with found values,
|
||
* and also build a filter - in what rows nothing was found.
|
||
* Then filter columns of "left" table.
|
||
*
|
||
* In case of ALL ... JOIN - form new columns with all found rows,
|
||
* and also fill 'offsets' array, describing how many times we need to replicate values of "left" table.
|
||
* Then replicate columns of "left" table.
|
||
*
|
||
* How Nullable keys are processed:
|
||
*
|
||
* NULLs never join to anything, even to each other.
|
||
* During building of map, we just skip keys with NULL value of any component.
|
||
* During joining, we simply treat rows with any NULLs in key as non joined.
|
||
*
|
||
* Default values for outer joins (LEFT, RIGHT, FULL):
|
||
*
|
||
* Behaviour is controlled by 'join_use_nulls' settings.
|
||
* If it is false, we substitute (global) default value for the data type, for non-joined rows
|
||
* (zero, empty string, etc. and NULL for Nullable data types).
|
||
* If it is true, we always generate Nullable column and substitute NULLs for non-joined rows,
|
||
* as in standard SQL.
|
||
*/
|
||
class HashJoin : public IJoin
|
||
{
|
||
public:
|
||
HashJoin(std::shared_ptr<TableJoin> table_join_, const Block & right_sample_block, bool any_take_last_row_ = false);
|
||
|
||
const TableJoin & getTableJoin() const override { return *table_join; }
|
||
|
||
/** Add block of data from right hand of JOIN to the map.
|
||
* Returns false, if some limit was exceeded and you should not insert more data.
|
||
*/
|
||
bool addJoinedBlock(const Block & block, bool check_limits) override;
|
||
|
||
void checkTypesOfKeys(const Block & block) const override;
|
||
|
||
/** Join data from the map (that was previously built by calls to addJoinedBlock) to the block with data from "left" table.
|
||
* Could be called from different threads in parallel.
|
||
*/
|
||
void joinBlock(Block & block, ExtraBlockPtr & not_processed) override;
|
||
|
||
/// Check joinGet arguments and infer the return type.
|
||
DataTypePtr joinGetCheckAndGetReturnType(const DataTypes & data_types, const String & column_name, bool or_null) const;
|
||
|
||
/// Used by joinGet function that turns StorageJoin into a dictionary.
|
||
ColumnWithTypeAndName joinGet(const Block & block, const Block & block_with_columns_to_add) const;
|
||
|
||
bool isFilled() const override { return from_storage_join || data->type == Type::DICT; }
|
||
|
||
JoinPipelineType pipelineType() const override
|
||
{
|
||
/// No need to process anything in the right stream if it's a dictionary will just join the left stream with it.
|
||
bool is_filled = from_storage_join || data->type == Type::DICT;
|
||
if (is_filled)
|
||
return JoinPipelineType::FilledRight;
|
||
|
||
/// Default pipeline processes right stream at first and then left.
|
||
return JoinPipelineType::FillRightFirst;
|
||
}
|
||
|
||
/** For RIGHT and FULL JOINs.
|
||
* A stream that will contain default values from left table, joined with rows from right table, that was not joined before.
|
||
* Use only after all calls to joinBlock was done.
|
||
* left_sample_block is passed without account of 'use_nulls' setting (columns will be converted to Nullable inside).
|
||
*/
|
||
std::shared_ptr<NotJoinedBlocks> getNonJoinedBlocks(
|
||
const Block & left_sample_block, const Block & result_sample_block, UInt64 max_block_size) const override;
|
||
|
||
/// Number of keys in all built JOIN maps.
|
||
size_t getTotalRowCount() const final;
|
||
/// Sum size in bytes of all buffers, used for JOIN maps and for all memory pools.
|
||
size_t getTotalByteCount() const final;
|
||
|
||
bool alwaysReturnsEmptySet() const final;
|
||
|
||
ASTTableJoin::Kind getKind() const { return kind; }
|
||
ASTTableJoin::Strictness getStrictness() const { return strictness; }
|
||
const std::optional<TypeIndex> & getAsofType() const { return asof_type; }
|
||
ASOF::Inequality getAsofInequality() const { return asof_inequality; }
|
||
bool anyTakeLastRow() const { return any_take_last_row; }
|
||
|
||
const ColumnWithTypeAndName & rightAsofKeyColumn() const;
|
||
|
||
/// Different types of keys for maps.
|
||
#define APPLY_FOR_JOIN_VARIANTS(M) \
|
||
M(key8) \
|
||
M(key16) \
|
||
M(key32) \
|
||
M(key64) \
|
||
M(key_string) \
|
||
M(key_fixed_string) \
|
||
M(keys128) \
|
||
M(keys256) \
|
||
M(hashed)
|
||
|
||
|
||
/// Used for reading from StorageJoin and applying joinGet function
|
||
#define APPLY_FOR_JOIN_VARIANTS_LIMITED(M) \
|
||
M(key8) \
|
||
M(key16) \
|
||
M(key32) \
|
||
M(key64) \
|
||
M(key_string) \
|
||
M(key_fixed_string)
|
||
|
||
enum class Type
|
||
{
|
||
EMPTY,
|
||
CROSS,
|
||
DICT,
|
||
#define M(NAME) NAME,
|
||
APPLY_FOR_JOIN_VARIANTS(M)
|
||
#undef M
|
||
};
|
||
|
||
/** Different data structures, that are used to perform JOIN.
|
||
*/
|
||
template <typename Mapped>
|
||
struct MapsTemplate
|
||
{
|
||
using MappedType = Mapped;
|
||
std::unique_ptr<FixedHashMap<UInt8, Mapped>> key8;
|
||
std::unique_ptr<FixedHashMap<UInt16, Mapped>> key16;
|
||
std::unique_ptr<HashMap<UInt32, Mapped, HashCRC32<UInt32>>> key32;
|
||
std::unique_ptr<HashMap<UInt64, Mapped, HashCRC32<UInt64>>> key64;
|
||
std::unique_ptr<HashMapWithSavedHash<StringRef, Mapped>> key_string;
|
||
std::unique_ptr<HashMapWithSavedHash<StringRef, Mapped>> key_fixed_string;
|
||
std::unique_ptr<HashMap<UInt128, Mapped, UInt128HashCRC32>> keys128;
|
||
std::unique_ptr<HashMap<UInt256, Mapped, UInt256HashCRC32>> keys256;
|
||
std::unique_ptr<HashMap<UInt128, Mapped, UInt128TrivialHash>> hashed;
|
||
|
||
void create(Type which)
|
||
{
|
||
switch (which)
|
||
{
|
||
case Type::EMPTY: break;
|
||
case Type::CROSS: break;
|
||
case Type::DICT: break;
|
||
|
||
#define M(NAME) \
|
||
case Type::NAME: NAME = std::make_unique<typename decltype(NAME)::element_type>(); break;
|
||
APPLY_FOR_JOIN_VARIANTS(M)
|
||
#undef M
|
||
}
|
||
}
|
||
|
||
size_t getTotalRowCount(Type which) const
|
||
{
|
||
switch (which)
|
||
{
|
||
case Type::EMPTY: return 0;
|
||
case Type::CROSS: return 0;
|
||
case Type::DICT: return 0;
|
||
|
||
#define M(NAME) \
|
||
case Type::NAME: return NAME ? NAME->size() : 0;
|
||
APPLY_FOR_JOIN_VARIANTS(M)
|
||
#undef M
|
||
}
|
||
|
||
__builtin_unreachable();
|
||
}
|
||
|
||
size_t getTotalByteCountImpl(Type which) const
|
||
{
|
||
switch (which)
|
||
{
|
||
case Type::EMPTY: return 0;
|
||
case Type::CROSS: return 0;
|
||
case Type::DICT: return 0;
|
||
|
||
#define M(NAME) \
|
||
case Type::NAME: return NAME ? NAME->getBufferSizeInBytes() : 0;
|
||
APPLY_FOR_JOIN_VARIANTS(M)
|
||
#undef M
|
||
}
|
||
|
||
__builtin_unreachable();
|
||
}
|
||
|
||
size_t getBufferSizeInCells(Type which) const
|
||
{
|
||
switch (which)
|
||
{
|
||
case Type::EMPTY: return 0;
|
||
case Type::CROSS: return 0;
|
||
case Type::DICT: return 0;
|
||
|
||
#define M(NAME) \
|
||
case Type::NAME: return NAME ? NAME->getBufferSizeInCells() : 0;
|
||
APPLY_FOR_JOIN_VARIANTS(M)
|
||
#undef M
|
||
}
|
||
|
||
__builtin_unreachable();
|
||
}
|
||
};
|
||
|
||
using MapsOne = MapsTemplate<RowRef>;
|
||
using MapsAll = MapsTemplate<RowRefList>;
|
||
using MapsAsof = MapsTemplate<AsofRowRefs>;
|
||
|
||
using MapsVariant = std::variant<MapsOne, MapsAll, MapsAsof>;
|
||
|
||
using RawBlockPtr = const Block *;
|
||
using BlockNullmapList = std::deque<std::pair<RawBlockPtr, ColumnPtr>>;
|
||
|
||
struct RightTableData
|
||
{
|
||
Type type = Type::EMPTY;
|
||
bool empty = true;
|
||
|
||
std::vector<MapsVariant> maps;
|
||
Block sample_block; /// Block as it would appear in the BlockList
|
||
BlocksList blocks; /// Blocks of "right" table.
|
||
BlockNullmapList blocks_nullmaps; /// Nullmaps for blocks of "right" table (if needed)
|
||
|
||
/// Additional data - strings for string keys and continuation elements of single-linked lists of references to rows.
|
||
Arena pool;
|
||
};
|
||
|
||
using RightTableDataPtr = std::shared_ptr<RightTableData>;
|
||
|
||
/// We keep correspondence between used_flags and hash table internal buffer.
|
||
/// Hash table cannot be modified during HashJoin lifetime and must be protected with lock.
|
||
void setLock(TableLockHolder rwlock_holder)
|
||
{
|
||
storage_join_lock = rwlock_holder;
|
||
}
|
||
|
||
void reuseJoinedData(const HashJoin & join);
|
||
|
||
RightTableDataPtr getJoinedData() const { return data; }
|
||
|
||
bool isUsed(size_t off) const { return used_flags.getUsedSafe(off); }
|
||
bool isUsed(const Block * block_ptr, size_t row_idx) const { return used_flags.getUsedSafe(block_ptr, row_idx); }
|
||
|
||
private:
|
||
template<bool> friend class NotJoinedHash;
|
||
|
||
friend class JoinSource;
|
||
|
||
std::shared_ptr<TableJoin> table_join;
|
||
ASTTableJoin::Kind kind;
|
||
ASTTableJoin::Strictness strictness;
|
||
|
||
/// This join was created from StorageJoin and it is already filled.
|
||
bool from_storage_join = false;
|
||
|
||
bool any_take_last_row; /// Overwrite existing values when encountering the same key again
|
||
std::optional<TypeIndex> asof_type;
|
||
ASOF::Inequality asof_inequality;
|
||
|
||
/// Right table data. StorageJoin shares it between many Join objects.
|
||
/// Flags that indicate that particular row already used in join.
|
||
/// Flag is stored for every record in hash map.
|
||
/// Number of this flags equals to hashtable buffer size (plus one for zero value).
|
||
/// Changes in hash table broke correspondence,
|
||
/// so we must guarantee constantness of hash table during HashJoin lifetime (using method setLock)
|
||
mutable JoinStuff::JoinUsedFlags used_flags;
|
||
RightTableDataPtr data;
|
||
std::vector<Sizes> key_sizes;
|
||
|
||
/// Block with columns from the right-side table.
|
||
Block right_sample_block;
|
||
/// Block with columns from the right-side table except key columns.
|
||
Block sample_block_with_columns_to_add;
|
||
/// Block with key columns in the same order they appear in the right-side table (duplicates appear once).
|
||
Block right_table_keys;
|
||
/// Block with key columns right-side table keys that are needed in result (would be attached after joined columns).
|
||
Block required_right_keys;
|
||
/// Left table column names that are sources for required_right_keys columns
|
||
std::vector<String> required_right_keys_sources;
|
||
|
||
Poco::Logger * log;
|
||
|
||
/// Should be set via setLock to protect hash table from modification from StorageJoin
|
||
/// If set HashJoin instance is not available for modification (addJoinedBlock)
|
||
TableLockHolder storage_join_lock = nullptr;
|
||
|
||
void dataMapInit(MapsVariant &);
|
||
|
||
const Block & savedBlockSample() const { return data->sample_block; }
|
||
|
||
/// Modify (structure) right block to save it in block list
|
||
Block structureRightBlock(const Block & stored_block) const;
|
||
void initRightBlockStructure(Block & saved_block_sample);
|
||
|
||
template <ASTTableJoin::Kind KIND, ASTTableJoin::Strictness STRICTNESS, typename Maps>
|
||
void joinBlockImpl(
|
||
Block & block,
|
||
const Block & block_with_columns_to_add,
|
||
const std::vector<const Maps *> & maps_,
|
||
bool is_join_get = false) const;
|
||
|
||
void joinBlockImplCross(Block & block, ExtraBlockPtr & not_processed) const;
|
||
|
||
static Type chooseMethod(ASTTableJoin::Kind kind, const ColumnRawPtrs & key_columns, Sizes & key_sizes);
|
||
|
||
bool empty() const;
|
||
bool overDictionary() const;
|
||
};
|
||
|
||
}
|