ClickHouse/src/Interpreters/MergeJoin.cpp
2022-10-12 15:25:23 +02:00

1187 lines
40 KiB
C++

#include <limits>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnLowCardinality.h>
#include <Core/SortCursor.h>
#include <Formats/TemporaryFileStreamLegacy.h>
#include <DataTypes/DataTypeNullable.h>
#include <DataTypes/DataTypesNumber.h>
#include <Interpreters/MergeJoin.h>
#include <Interpreters/TableJoin.h>
#include <Interpreters/JoinUtils.h>
#include <Interpreters/TemporaryDataOnDisk.h>
#include <Interpreters/sortBlock.h>
#include <Processors/Sources/BlocksListSource.h>
#include <QueryPipeline/QueryPipelineBuilder.h>
#include <Processors/Transforms/MergeSortingTransform.h>
#include <Processors/Executors/PullingPipelineExecutor.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NOT_IMPLEMENTED;
extern const int PARAMETER_OUT_OF_BOUND;
extern const int ILLEGAL_COLUMN;
extern const int LOGICAL_ERROR;
}
namespace
{
String deriveTempName(const String & name, JoinTableSide block_side)
{
if (block_side == JoinTableSide::Left)
return "--pmj_cond_left_" + name;
else
return "--pmj_cond_right_" + name;
}
/*
* Convert column with conditions for left or right table to join to joining key.
* Input column type is UInt8 output is Nullable(UInt8).
* 0 converted to NULL and such rows won't be joined,
* 1 converted to 0 (any constant non-NULL value to join)
*/
ColumnWithTypeAndName condtitionColumnToJoinable(const Block & block, const String & src_column_name, JoinTableSide block_side)
{
size_t res_size = block.rows();
auto data_col = ColumnUInt8::create(res_size, 0);
auto null_map = ColumnUInt8::create(res_size, 0);
if (!src_column_name.empty())
{
auto join_mask = JoinCommon::getColumnAsMask(block, src_column_name);
if (!join_mask.isConstant())
{
for (size_t i = 0; i < res_size; ++i)
null_map->getData()[i] = join_mask.isRowFiltered(i);
}
}
ColumnPtr res_col = ColumnNullable::create(std::move(data_col), std::move(null_map));
DataTypePtr res_col_type = std::make_shared<DataTypeNullable>(std::make_shared<DataTypeUInt8>());
String res_name = deriveTempName(src_column_name, block_side);
if (block.has(res_name))
throw Exception(ErrorCodes::ILLEGAL_COLUMN, "Conflicting column name '{}' in block {}", res_name, block.dumpStructure());
return {res_col, res_col_type, res_name};
}
template <bool has_left_nulls, bool has_right_nulls>
int nullableCompareAt(const IColumn & left_column, const IColumn & right_column, size_t lhs_pos, size_t rhs_pos)
{
static constexpr int null_direction_hint = 1;
if constexpr (has_left_nulls && has_right_nulls)
{
const auto * left_nullable = checkAndGetColumn<ColumnNullable>(left_column);
const auto * right_nullable = checkAndGetColumn<ColumnNullable>(right_column);
if (left_nullable && right_nullable)
{
int res = left_column.compareAt(lhs_pos, rhs_pos, right_column, null_direction_hint);
if (res)
return res;
/// NULL != NULL case
if (left_column.isNullAt(lhs_pos))
return null_direction_hint;
return 0;
}
}
if constexpr (has_left_nulls)
{
if (const auto * left_nullable = checkAndGetColumn<ColumnNullable>(left_column))
{
if (left_column.isNullAt(lhs_pos))
return null_direction_hint;
return left_nullable->getNestedColumn().compareAt(lhs_pos, rhs_pos, right_column, null_direction_hint);
}
}
if constexpr (has_right_nulls)
{
if (const auto * right_nullable = checkAndGetColumn<ColumnNullable>(right_column))
{
if (right_column.isNullAt(rhs_pos))
return -null_direction_hint;
return left_column.compareAt(lhs_pos, rhs_pos, right_nullable->getNestedColumn(), null_direction_hint);
}
}
return left_column.compareAt(lhs_pos, rhs_pos, right_column, null_direction_hint);
}
/// Get first and last row from sorted block
Block extractMinMax(const Block & block, const Block & keys)
{
if (block.rows() == 0)
throw Exception("Unexpected empty block", ErrorCodes::LOGICAL_ERROR);
Block min_max = keys.cloneEmpty();
MutableColumns columns = min_max.mutateColumns();
for (size_t i = 0; i < columns.size(); ++i)
{
const auto & src_column = block.getByName(min_max.getByPosition(i).name);
columns[i]->insertFrom(*src_column.column, 0);
columns[i]->insertFrom(*src_column.column, block.rows() - 1);
}
min_max.setColumns(std::move(columns));
return min_max;
}
}
class RowBitmaps
{
public:
struct Bitmap
{
using Container = std::vector<bool>;
std::mutex mutex;
Container bitmap;
size_t size() const { return bitmap.size(); }
bool empty() const { return bitmap.empty(); }
void applyOr(Container && addition) noexcept
{
std::lock_guard lock(mutex);
if (bitmap.empty())
{
bitmap.swap(addition);
return;
}
/// TODO: simd bit or (need padding and tail in container)
for (size_t i = 0; i < bitmap.size(); ++i)
if (addition[i])
bitmap[i] = true;
}
};
using Container = Bitmap::Container;
explicit RowBitmaps(size_t size)
{
maps.reserve(size);
for (size_t i = 0; i < size; ++i)
maps.emplace_back(std::make_unique<Bitmap>());
}
bool used(size_t bitmap_number) const
{
return !maps[bitmap_number]->empty();
}
void applyOr(size_t bitmap_number, Container && addition) noexcept
{
maps[bitmap_number]->applyOr(std::move(addition));
}
IColumn::Filter getNotUsed(size_t bitmap_number) const
{
const Container & bitmap = maps[bitmap_number]->bitmap;
IColumn::Filter filter(bitmap.size());
for (size_t i = 0; i < bitmap.size(); ++i)
filter[i] = !bitmap[i];
return filter;
}
private:
std::vector<std::unique_ptr<Bitmap>> maps;
};
struct MergeJoinEqualRange
{
size_t left_start = 0;
size_t right_start = 0;
size_t left_length = 0;
size_t right_length = 0;
bool empty() const { return !left_length && !right_length; }
};
using Range = MergeJoinEqualRange;
class MergeJoinCursor
{
public:
MergeJoinCursor(const Block & block, const SortDescription & desc_)
: impl(block, desc_)
{
/// SortCursorImpl can work with permutation, but MergeJoinCursor can't.
if (impl.permutation)
throw Exception("Logical error: MergeJoinCursor doesn't support permutation", ErrorCodes::LOGICAL_ERROR);
}
size_t position() const { return impl.getRow(); }
size_t end() const { return impl.rows; }
bool atEnd() const { return impl.getRow() >= impl.rows; }
void nextN(size_t num) { impl.getPosRef() += num; }
void setCompareNullability(const MergeJoinCursor & rhs)
{
has_left_nullable = false;
has_right_nullable = false;
for (size_t i = 0; i < impl.sort_columns_size; ++i)
{
has_left_nullable = has_left_nullable || isColumnNullable(*impl.sort_columns[i]);
has_right_nullable = has_right_nullable || isColumnNullable(*rhs.impl.sort_columns[i]);
}
}
Range getNextEqualRange(MergeJoinCursor & rhs)
{
if (has_left_nullable && has_right_nullable)
return getNextEqualRangeImpl<true, true>(rhs);
else if (has_left_nullable)
return getNextEqualRangeImpl<true, false>(rhs);
else if (has_right_nullable)
return getNextEqualRangeImpl<false, true>(rhs);
return getNextEqualRangeImpl<false, false>(rhs);
}
int intersect(const Block & min_max, const Names & key_names)
{
if (end() == 0 || min_max.rows() != 2)
throw Exception("Unexpected block size", ErrorCodes::LOGICAL_ERROR);
size_t last_position = end() - 1;
int first_vs_max = 0;
int last_vs_min = 0;
for (size_t i = 0; i < impl.sort_columns_size; ++i)
{
const auto & left_column = *impl.sort_columns[i];
const auto & right_column = *min_max.getByName(key_names[i]).column; /// cannot get by position cause of possible duplicates
if (!first_vs_max)
first_vs_max = nullableCompareAt<true, true>(left_column, right_column, position(), 1);
if (!last_vs_min)
last_vs_min = nullableCompareAt<true, true>(left_column, right_column, last_position, 0);
}
if (first_vs_max > 0)
return 1;
if (last_vs_min < 0)
return -1;
return 0;
}
private:
SortCursorImpl impl;
bool has_left_nullable = false;
bool has_right_nullable = false;
template <bool left_nulls, bool right_nulls>
Range getNextEqualRangeImpl(MergeJoinCursor & rhs)
{
while (!atEnd() && !rhs.atEnd())
{
int cmp = compareAtCursor<left_nulls, right_nulls>(rhs);
if (cmp < 0)
impl.next();
else if (cmp > 0)
rhs.impl.next();
else if (!cmp)
return Range{impl.getRow(), rhs.impl.getRow(), getEqualLength(), rhs.getEqualLength()};
}
return Range{impl.getRow(), rhs.impl.getRow(), 0, 0};
}
template <bool left_nulls, bool right_nulls>
int ALWAYS_INLINE compareAtCursor(const MergeJoinCursor & rhs) const
{
for (size_t i = 0; i < impl.sort_columns_size; ++i)
{
const auto * left_column = impl.sort_columns[i];
const auto * right_column = rhs.impl.sort_columns[i];
int res = nullableCompareAt<left_nulls, right_nulls>(*left_column, *right_column, impl.getRow(), rhs.impl.getRow());
if (res)
return res;
}
return 0;
}
/// Expects !atEnd()
size_t getEqualLength()
{
size_t pos = impl.getRow() + 1;
for (; pos < impl.rows; ++pos)
if (!samePrev(pos))
break;
return pos - impl.getRow();
}
/// Expects lhs_pos > 0
bool ALWAYS_INLINE samePrev(size_t lhs_pos) const
{
for (size_t i = 0; i < impl.sort_columns_size; ++i)
if (impl.sort_columns[i]->compareAt(lhs_pos - 1, lhs_pos, *(impl.sort_columns[i]), 1) != 0)
return false;
return true;
}
};
namespace
{
MutableColumns makeMutableColumns(const Block & block, size_t rows_to_reserve = 0)
{
MutableColumns columns;
columns.reserve(block.columns());
for (const auto & src_column : block)
{
columns.push_back(src_column.column->cloneEmpty());
columns.back()->reserve(rows_to_reserve);
}
return columns;
}
void makeSortAndMerge(const Names & keys, SortDescription & sort, SortDescription & merge)
{
NameSet unique_keys;
for (const auto & sd: merge)
unique_keys.insert(sd.column_name);
for (const auto & key_name : keys)
{
merge.emplace_back(key_name);
if (!unique_keys.contains(key_name))
{
unique_keys.insert(key_name);
sort.emplace_back(key_name);
}
}
}
void copyLeftRange(const Block & block, MutableColumns & columns, size_t start, size_t rows_to_add)
{
for (size_t i = 0; i < block.columns(); ++i)
{
const auto & src_column = block.getByPosition(i).column;
columns[i]->insertRangeFrom(*src_column, start, rows_to_add);
}
}
void copyRightRange(const Block & right_block, const Block & right_columns_to_add, MutableColumns & columns,
size_t row_position, size_t rows_to_add)
{
for (size_t i = 0; i < right_columns_to_add.columns(); ++i)
{
const auto & src_column = right_block.getByName(right_columns_to_add.getByPosition(i).name).column;
auto & dst_column = columns[i];
auto * dst_nullable = typeid_cast<ColumnNullable *>(dst_column.get());
if (dst_nullable && !isColumnNullable(*src_column))
dst_nullable->insertManyFromNotNullable(*src_column, row_position, rows_to_add);
else
dst_column->insertManyFrom(*src_column, row_position, rows_to_add);
}
}
void joinEqualsAnyLeft(const Block & right_block, const Block & right_columns_to_add, MutableColumns & right_columns, const Range & range)
{
copyRightRange(right_block, right_columns_to_add, right_columns, range.right_start, range.left_length);
}
template <bool is_all>
bool joinEquals(const Block & left_block, const Block & right_block, const Block & right_columns_to_add,
MutableColumns & left_columns, MutableColumns & right_columns, Range & range, size_t max_rows [[maybe_unused]])
{
bool one_more = true;
if constexpr (is_all)
{
size_t range_rows = range.left_length * range.right_length;
if (range_rows > max_rows)
{
/// We need progress. So we join at least one right row.
range.right_length = max_rows / range.left_length;
if (!range.right_length)
range.right_length = 1;
one_more = false;
}
size_t left_rows_to_add = range.left_length;
size_t row_position = range.right_start;
for (size_t right_row = 0; right_row < range.right_length; ++right_row, ++row_position)
{
copyLeftRange(left_block, left_columns, range.left_start, left_rows_to_add);
copyRightRange(right_block, right_columns_to_add, right_columns, row_position, left_rows_to_add);
}
}
else
{
size_t left_rows_to_add = range.left_length;
copyLeftRange(left_block, left_columns, range.left_start, left_rows_to_add);
copyRightRange(right_block, right_columns_to_add, right_columns, range.right_start, left_rows_to_add);
}
return one_more;
}
template <bool copy_left>
void joinInequalsLeft(const Block & left_block, MutableColumns & left_columns,
const Block & right_block, MutableColumns & right_columns,
size_t start, size_t end)
{
if (end <= start)
return;
size_t rows_to_add = end - start;
if constexpr (copy_left)
copyLeftRange(left_block, left_columns, start, rows_to_add);
for (size_t i = 0; i < right_columns.size(); ++i)
{
JoinCommon::addDefaultValues(*right_columns[i], right_block.getByPosition(i).type, rows_to_add);
}
}
}
MergeJoin::MergeJoin(std::shared_ptr<TableJoin> table_join_, const Block & right_sample_block_)
: table_join(table_join_)
, size_limits(table_join->sizeLimits())
, right_sample_block(right_sample_block_)
, is_any_join(table_join->strictness() == JoinStrictness::Any)
, is_all_join(table_join->strictness() == JoinStrictness::All)
, is_semi_join(table_join->strictness() == JoinStrictness::Semi)
, is_inner(isInner(table_join->kind()))
, is_left(isLeft(table_join->kind()))
, is_right(isRight(table_join->kind()))
, is_full(isFull(table_join->kind()))
, max_joined_block_rows(table_join->maxJoinedBlockRows())
, max_rows_in_right_block(table_join->maxRowsInRightBlock())
, max_files_to_merge(table_join->maxFilesToMerge())
, log(&Poco::Logger::get("MergeJoin"))
{
switch (table_join->strictness())
{
case JoinStrictness::All:
break;
case JoinStrictness::Any:
case JoinStrictness::Semi:
if (!is_left && !is_inner)
throw Exception("Not supported. MergeJoin supports SEMI and ANY variants only for LEFT and INNER JOINs.",
ErrorCodes::NOT_IMPLEMENTED);
break;
default:
throw Exception("Not supported. MergeJoin supports ALL, ANY and SEMI JOINs variants.", ErrorCodes::NOT_IMPLEMENTED);
}
if (!max_rows_in_right_block)
throw Exception("partial_merge_join_rows_in_right_blocks cannot be zero", ErrorCodes::PARAMETER_OUT_OF_BOUND);
if (max_files_to_merge < 2)
throw Exception("max_files_to_merge cannot be less than 2", ErrorCodes::PARAMETER_OUT_OF_BOUND);
if (!size_limits.hasLimits())
{
size_limits.max_bytes = table_join->defaultMaxBytes();
if (!size_limits.max_bytes)
throw Exception("No limit for MergeJoin (max_rows_in_join, max_bytes_in_join or default_max_bytes_in_join have to be set)",
ErrorCodes::PARAMETER_OUT_OF_BOUND);
}
if (!table_join->oneDisjunct())
throw DB::Exception(ErrorCodes::NOT_IMPLEMENTED, "MergeJoin does not support OR in JOIN ON section");
const auto & onexpr = table_join->getOnlyClause();
std::tie(mask_column_name_left, mask_column_name_right) = onexpr.condColumnNames();
/// Add auxiliary joining keys to join only rows where conditions from JOIN ON sections holds
/// Input boolean column converted to nullable and only rows with non NULLS value will be joined
if (!mask_column_name_left.empty() || !mask_column_name_right.empty())
{
JoinCommon::checkTypesOfMasks({}, "", right_sample_block, mask_column_name_right);
key_names_left.push_back(deriveTempName(mask_column_name_left, JoinTableSide::Left));
key_names_right.push_back(deriveTempName(mask_column_name_right, JoinTableSide::Right));
}
key_names_left.insert(key_names_left.end(), onexpr.key_names_left.begin(), onexpr.key_names_left.end());
key_names_right.insert(key_names_right.end(), onexpr.key_names_right.begin(), onexpr.key_names_right.end());
addConditionJoinColumn(right_sample_block, JoinTableSide::Right);
JoinCommon::splitAdditionalColumns(key_names_right, right_sample_block, right_table_keys, right_columns_to_add);
for (const auto & right_key : key_names_right)
{
if (right_sample_block.getByName(right_key).type->lowCardinality())
lowcard_right_keys.push_back(right_key);
}
JoinCommon::convertToFullColumnsInplace(right_table_keys);
JoinCommon::convertToFullColumnsInplace(right_sample_block, key_names_right);
const NameSet required_right_keys = table_join->requiredRightKeys();
for (const auto & column : right_table_keys)
if (required_right_keys.contains(column.name))
right_columns_to_add.insert(ColumnWithTypeAndName{nullptr, column.type, column.name});
JoinCommon::createMissedColumns(right_columns_to_add);
makeSortAndMerge(key_names_left, left_sort_description, left_merge_description);
makeSortAndMerge(key_names_right, right_sort_description, right_merge_description);
LOG_DEBUG(log, "Joining keys: left [{}], right [{}]", fmt::join(key_names_left, ", "), fmt::join(key_names_right, ", "));
if (size_t max_bytes = table_join->maxBytesInLeftBuffer(); max_bytes > 0)
{
/// Disabled due to https://github.com/ClickHouse/ClickHouse/issues/31009
// left_blocks_buffer = std::make_shared<SortedBlocksBuffer>(left_sort_description, max_bytes);
LOG_WARNING(log, "`partial_merge_join_left_table_buffer_bytes` is disabled in current version of ClickHouse");
UNUSED(left_blocks_buffer);
}
}
/// Has to be called even if totals are empty
void MergeJoin::setTotals(const Block & totals_block)
{
IJoin::setTotals(totals_block);
mergeRightBlocks();
if (is_right || is_full)
used_rows_bitmap = std::make_shared<RowBitmaps>(getRightBlocksCount());
}
void MergeJoin::mergeRightBlocks()
{
if (is_in_memory)
mergeInMemoryRightBlocks();
else
mergeFlushedRightBlocks();
}
void MergeJoin::mergeInMemoryRightBlocks()
{
std::lock_guard lock(rwlock);
if (right_blocks.empty())
return;
Pipe source(std::make_shared<BlocksListSource>(std::move(right_blocks.blocks)));
right_blocks.clear();
QueryPipelineBuilder builder;
builder.init(std::move(source));
/// TODO: there should be no split keys by blocks for RIGHT|FULL JOIN
builder.addTransform(std::make_shared<MergeSortingTransform>(
builder.getHeader(), right_sort_description, max_rows_in_right_block, 0, false, 0, 0, 0, nullptr, 0));
auto pipeline = QueryPipelineBuilder::getPipeline(std::move(builder));
PullingPipelineExecutor executor(pipeline);
Block block;
while (executor.pull(block))
{
if (!block.rows())
continue;
if (skip_not_intersected)
min_max_right_blocks.emplace_back(extractMinMax(block, right_table_keys));
right_blocks.countBlockSize(block);
loaded_right_blocks.emplace_back(std::make_shared<Block>(std::move(block)));
}
}
void MergeJoin::mergeFlushedRightBlocks()
{
std::lock_guard lock(rwlock);
auto callback = [&](const Block & block)
{
if (skip_not_intersected)
min_max_right_blocks.emplace_back(extractMinMax(block, right_table_keys));
right_blocks.countBlockSize(block);
};
flushed_right_blocks = disk_writer->finishMerge(callback);
disk_writer.reset();
/// Get memory limit or approximate it from row limit and bytes per row factor
UInt64 memory_limit = size_limits.max_bytes;
UInt64 rows_limit = size_limits.max_rows;
if (!memory_limit && rows_limit)
memory_limit = right_blocks.bytes * rows_limit / right_blocks.row_count;
cached_right_blocks = std::make_unique<Cache>(memory_limit);
}
bool MergeJoin::saveRightBlock(Block && block)
{
if (is_in_memory)
{
std::lock_guard lock(rwlock);
if (!is_in_memory)
{
disk_writer->insert(std::move(block));
return true;
}
right_blocks.insert(std::move(block));
bool has_memory = size_limits.softCheck(right_blocks.row_count, right_blocks.bytes);
if (!has_memory)
{
initRightTableWriter();
is_in_memory = false;
}
}
else
disk_writer->insert(std::move(block));
return true;
}
Block MergeJoin::modifyRightBlock(const Block & src_block) const
{
Block block = materializeBlock(src_block);
JoinCommon::convertToFullColumnsInplace(block, table_join->getOnlyClause().key_names_right);
return block;
}
bool MergeJoin::addJoinedBlock(const Block & src_block, bool)
{
Block block = modifyRightBlock(src_block);
addConditionJoinColumn(block, JoinTableSide::Right);
sortBlock(block, right_sort_description);
return saveRightBlock(std::move(block));
}
void MergeJoin::checkTypesOfKeys(const Block & block) const
{
/// Do not check auxailary column for extra conditions, use original key names
const auto & onexpr = table_join->getOnlyClause();
JoinCommon::checkTypesOfKeys(block, onexpr.key_names_left, right_table_keys, onexpr.key_names_right);
}
void MergeJoin::joinBlock(Block & block, ExtraBlockPtr & not_processed)
{
Names lowcard_keys = lowcard_right_keys;
if (block)
{
/// We need to check type of masks before `addConditionJoinColumn`, because it assumes that types is correct
JoinCommon::checkTypesOfMasks(block, mask_column_name_left, right_sample_block, mask_column_name_right);
/// Add auxiliary column, will be removed after joining
addConditionJoinColumn(block, JoinTableSide::Left);
/// Types of keys can be checked only after `checkTypesOfKeys`
JoinCommon::checkTypesOfKeys(block, key_names_left, right_table_keys, key_names_right);
materializeBlockInplace(block);
for (const auto & column_name : key_names_left)
{
if (block.getByName(column_name).type->lowCardinality())
lowcard_keys.push_back(column_name);
}
JoinCommon::convertToFullColumnsInplace(block, key_names_left, false);
sortBlock(block, left_sort_description);
}
if (!not_processed && left_blocks_buffer)
{
if (!block || block.rows())
block = left_blocks_buffer->exchange(std::move(block));
if (!block)
return;
}
if (is_in_memory)
{
if (is_all_join)
joinSortedBlock<true, true>(block, not_processed);
else
joinSortedBlock<true, false>(block, not_processed);
}
else
{
if (is_all_join)
joinSortedBlock<false, true>(block, not_processed);
else
joinSortedBlock<false, false>(block, not_processed);
}
/// Back thread even with no data. We have some unfinished data in buffer.
if (!not_processed && left_blocks_buffer)
not_processed = std::make_shared<NotProcessed>(NotProcessed{{}, 0, 0, 0, 0});
if (needConditionJoinColumn())
block.erase(deriveTempName(mask_column_name_left, JoinTableSide::Left));
JoinCommon::restoreLowCardinalityInplace(block, lowcard_keys);
}
template <bool in_memory, bool is_all>
void MergeJoin::joinSortedBlock(Block & block, ExtraBlockPtr & not_processed)
{
size_t rows_to_reserve = is_left ? block.rows() : 0;
MutableColumns left_columns = makeMutableColumns(block, (is_all ? rows_to_reserve : 0));
MutableColumns right_columns = makeMutableColumns(right_columns_to_add, rows_to_reserve);
MergeJoinCursor left_cursor(block, left_merge_description);
size_t left_key_tail = 0;
size_t skip_right = 0;
size_t right_blocks_count = rightBlocksCount<in_memory>();
size_t starting_right_block = 0;
if (not_processed)
{
auto & continuation = static_cast<NotProcessed &>(*not_processed);
left_cursor.nextN(continuation.left_position);
left_key_tail = continuation.left_key_tail;
skip_right = continuation.right_position;
starting_right_block = continuation.right_block;
not_processed.reset();
}
bool with_left_inequals = (is_left && !is_semi_join) || is_full;
if (with_left_inequals)
{
for (size_t i = starting_right_block; i < right_blocks_count; ++i)
{
if (left_cursor.atEnd())
break;
if (skip_not_intersected)
{
int intersection = left_cursor.intersect(min_max_right_blocks[i], key_names_right);
if (intersection < 0)
break; /// (left) ... (right)
if (intersection > 0)
{
skip_right = 0;
continue; /// (right) ... (left)
}
}
/// Use skip_right as ref. It would be updated in join.
RightBlockInfo right_block(loadRightBlock<in_memory>(i), i, skip_right, used_rows_bitmap.get());
if (!leftJoin<is_all>(left_cursor, block, right_block, left_columns, right_columns, left_key_tail))
{
not_processed = extraBlock<is_all>(block, std::move(left_columns), std::move(right_columns),
left_cursor.position(), left_key_tail, skip_right, i);
return;
}
}
left_cursor.nextN(left_key_tail);
joinInequalsLeft<is_all>(block, left_columns, right_columns_to_add, right_columns, left_cursor.position(), left_cursor.end());
changeLeftColumns(block, std::move(left_columns));
addRightColumns(block, std::move(right_columns));
}
else /// no inequals
{
for (size_t i = starting_right_block; i < right_blocks_count; ++i)
{
if (left_cursor.atEnd())
break;
if (skip_not_intersected)
{
int intersection = left_cursor.intersect(min_max_right_blocks[i], key_names_right);
if (intersection < 0)
break; /// (left) ... (right)
if (intersection > 0)
{
skip_right = 0;
continue; /// (right) ... (left)
}
}
/// Use skip_right as ref. It would be updated in join.
RightBlockInfo right_block(loadRightBlock<in_memory>(i), i, skip_right, used_rows_bitmap.get());
if constexpr (is_all)
{
if (!allInnerJoin(left_cursor, block, right_block, left_columns, right_columns, left_key_tail))
{
not_processed = extraBlock<is_all>(block, std::move(left_columns), std::move(right_columns),
left_cursor.position(), left_key_tail, skip_right, i);
return;
}
}
else
semiLeftJoin(left_cursor, block, right_block, left_columns, right_columns);
}
left_cursor.nextN(left_key_tail);
changeLeftColumns(block, std::move(left_columns));
addRightColumns(block, std::move(right_columns));
}
}
static size_t maxRangeRows(size_t current_rows, size_t max_rows)
{
if (!max_rows)
return std::numeric_limits<size_t>::max();
if (current_rows >= max_rows)
return 0;
return max_rows - current_rows;
}
template <bool is_all>
bool MergeJoin::leftJoin(MergeJoinCursor & left_cursor, const Block & left_block, RightBlockInfo & right_block_info,
MutableColumns & left_columns, MutableColumns & right_columns, size_t & left_key_tail)
{
const Block & right_block = *right_block_info.block;
MergeJoinCursor right_cursor(right_block, right_merge_description);
left_cursor.setCompareNullability(right_cursor);
/// Set right cursor position in first continuation right block
if constexpr (is_all)
{
right_cursor.nextN(right_block_info.skip);
right_block_info.skip = 0;
}
while (!left_cursor.atEnd() && !right_cursor.atEnd())
{
/// Not zero left_key_tail means there were equality for the last left key in previous leftJoin() call.
/// Do not join it twice: join only if it's equal with a first right key of current leftJoin() call and skip otherwise.
size_t left_unequal_position = left_cursor.position() + left_key_tail;
left_key_tail = 0;
Range range = left_cursor.getNextEqualRange(right_cursor);
joinInequalsLeft<is_all>(left_block, left_columns, right_columns_to_add, right_columns, left_unequal_position, range.left_start);
if (range.empty())
break;
if constexpr (is_all)
{
right_block_info.setUsed(range.right_start, range.right_length);
size_t max_rows = maxRangeRows(left_columns[0]->size(), max_joined_block_rows);
if (!joinEquals<true>(left_block, right_block, right_columns_to_add, left_columns, right_columns, range, max_rows))
{
right_cursor.nextN(range.right_length);
right_block_info.skip = right_cursor.position();
left_key_tail = range.left_length;
return false;
}
}
else
joinEqualsAnyLeft(right_block, right_columns_to_add, right_columns, range);
right_cursor.nextN(range.right_length);
/// Do not run over last left keys for ALL JOIN (cause of possible duplicates in next right block)
if constexpr (is_all)
{
if (right_cursor.atEnd())
{
left_key_tail = range.left_length;
break;
}
}
left_cursor.nextN(range.left_length);
}
return true;
}
bool MergeJoin::allInnerJoin(MergeJoinCursor & left_cursor, const Block & left_block, RightBlockInfo & right_block_info,
MutableColumns & left_columns, MutableColumns & right_columns, size_t & left_key_tail)
{
const Block & right_block = *right_block_info.block;
MergeJoinCursor right_cursor(right_block, right_merge_description);
left_cursor.setCompareNullability(right_cursor);
/// Set right cursor position in first continuation right block
right_cursor.nextN(right_block_info.skip);
right_block_info.skip = 0;
while (!left_cursor.atEnd() && !right_cursor.atEnd())
{
Range range = left_cursor.getNextEqualRange(right_cursor);
if (range.empty())
break;
right_block_info.setUsed(range.right_start, range.right_length);
size_t max_rows = maxRangeRows(left_columns[0]->size(), max_joined_block_rows);
if (!joinEquals<true>(left_block, right_block, right_columns_to_add, left_columns, right_columns, range, max_rows))
{
right_cursor.nextN(range.right_length);
right_block_info.skip = right_cursor.position();
return false;
}
right_cursor.nextN(range.right_length);
/// Do not run over last left keys for ALL JOIN (cause of possible duplicates in next right block)
if (right_cursor.atEnd())
{
left_key_tail = range.left_length;
break;
}
left_cursor.nextN(range.left_length);
}
return true;
}
bool MergeJoin::semiLeftJoin(MergeJoinCursor & left_cursor, const Block & left_block, const RightBlockInfo & right_block_info,
MutableColumns & left_columns, MutableColumns & right_columns)
{
const Block & right_block = *right_block_info.block;
MergeJoinCursor right_cursor(right_block, right_merge_description);
left_cursor.setCompareNullability(right_cursor);
while (!left_cursor.atEnd() && !right_cursor.atEnd())
{
Range range = left_cursor.getNextEqualRange(right_cursor);
if (range.empty())
break;
joinEquals<false>(left_block, right_block, right_columns_to_add, left_columns, right_columns, range, 0);
right_cursor.nextN(range.right_length);
left_cursor.nextN(range.left_length);
}
return true;
}
void MergeJoin::changeLeftColumns(Block & block, MutableColumns && columns) const
{
if (is_left && is_any_join)
return;
block.setColumns(std::move(columns));
}
void MergeJoin::addRightColumns(Block & block, MutableColumns && right_columns)
{
for (size_t i = 0; i < right_columns_to_add.columns(); ++i)
{
const auto & column = right_columns_to_add.getByPosition(i);
block.insert(ColumnWithTypeAndName{std::move(right_columns[i]), column.type, column.name});
}
}
/// Split block into processed (result) and not processed. Not processed block would be joined next time.
template <bool is_all>
ExtraBlockPtr MergeJoin::extraBlock(Block & processed, MutableColumns && left_columns, MutableColumns && right_columns,
size_t left_position [[maybe_unused]], size_t left_key_tail [[maybe_unused]],
size_t right_position [[maybe_unused]], size_t right_block_number [[maybe_unused]])
{
ExtraBlockPtr not_processed;
if constexpr (is_all)
{
not_processed = std::make_shared<NotProcessed>(
NotProcessed{{processed.cloneEmpty()}, left_position, left_key_tail, right_position, right_block_number});
not_processed->block.swap(processed);
changeLeftColumns(processed, std::move(left_columns));
addRightColumns(processed, std::move(right_columns));
}
return not_processed;
}
template <bool in_memory>
size_t MergeJoin::rightBlocksCount() const
{
if constexpr (!in_memory)
return flushed_right_blocks.size();
else
return loaded_right_blocks.size();
}
template <bool in_memory>
std::shared_ptr<Block> MergeJoin::loadRightBlock(size_t pos) const
{
if constexpr (!in_memory)
{
auto load_func = [&]() -> std::shared_ptr<Block>
{
TemporaryFileStreamLegacy input(flushed_right_blocks[pos]->getPath(), materializeBlock(right_sample_block));
return std::make_shared<Block>(input.block_in->read());
};
return cached_right_blocks->getOrSet(pos, load_func).first;
}
else
return loaded_right_blocks[pos];
}
void MergeJoin::initRightTableWriter()
{
disk_writer = std::make_unique<SortedBlocksWriter>(size_limits, table_join->getTemporaryVolume(),
right_sample_block, right_sort_description, max_rows_in_right_block, max_files_to_merge,
table_join->temporaryFilesCodec());
disk_writer->addBlocks(right_blocks);
right_blocks.clear();
}
/// Stream from not joined earlier rows of the right table.
class NotJoinedMerge final : public NotJoinedBlocks::RightColumnsFiller
{
public:
NotJoinedMerge(const MergeJoin & parent_, UInt64 max_block_size_)
: parent(parent_), max_block_size(max_block_size_)
{}
Block getEmptyBlock() override { return parent.modifyRightBlock(parent.right_sample_block).cloneEmpty(); }
size_t fillColumns(MutableColumns & columns_right) override
{
const RowBitmaps & bitmaps = *parent.used_rows_bitmap;
size_t rows_added = 0;
size_t blocks_count = parent.getRightBlocksCount();
for (; block_number < blocks_count; ++block_number)
{
auto right_block = parent.getRightBlock(block_number);
if (bitmaps.used(block_number))
{
IColumn::Filter not_used = bitmaps.getNotUsed(block_number);
for (const auto & row : not_used)
if (row)
++rows_added;
for (size_t col = 0; col < columns_right.size(); ++col)
{
/// TODO: IColumn::filteredInsertRangeFrom() ?
ColumnPtr portion = right_block->getByPosition(col).column->filter(not_used, 1);
columns_right[col]->insertRangeFrom(*portion, 0, portion->size());
}
}
else
{
rows_added += right_block->rows();
for (size_t col = 0; col < columns_right.size(); ++col)
{
const IColumn & column = *right_block->getByPosition(col).column;
columns_right[col]->insertRangeFrom(column, 0, column.size());
}
}
if (rows_added >= max_block_size)
{
++block_number;
break;
}
}
return rows_added;
}
private:
const MergeJoin & parent;
size_t max_block_size;
size_t block_number = 0;
};
std::shared_ptr<NotJoinedBlocks> MergeJoin::getNonJoinedBlocks(
const Block & left_sample_block, const Block & result_sample_block, UInt64 max_block_size) const
{
if (table_join->strictness() == JoinStrictness::All && (is_right || is_full))
{
size_t left_columns_count = left_sample_block.columns();
assert(left_columns_count == result_sample_block.columns() - right_columns_to_add.columns());
auto non_joined = std::make_unique<NotJoinedMerge>(*this, max_block_size);
return std::make_shared<NotJoinedBlocks>(std::move(non_joined), result_sample_block, left_columns_count, table_join->leftToRightKeyRemap());
}
return nullptr;
}
bool MergeJoin::needConditionJoinColumn() const
{
return !mask_column_name_left.empty() || !mask_column_name_right.empty();
}
void MergeJoin::addConditionJoinColumn(Block & block, JoinTableSide block_side) const
{
if (needConditionJoinColumn())
{
if (block_side == JoinTableSide::Left)
block.insert(condtitionColumnToJoinable(block, mask_column_name_left, block_side));
else
block.insert(condtitionColumnToJoinable(block, mask_column_name_right, block_side));
}
}
bool MergeJoin::isSupported(const std::shared_ptr<TableJoin> & table_join)
{
auto kind = table_join->kind();
auto strictness = table_join->strictness();
bool is_any = (strictness == JoinStrictness::Any);
bool is_all = (strictness == JoinStrictness::All);
bool is_semi = (strictness == JoinStrictness::Semi);
bool all_join = is_all && (isInner(kind) || isLeft(kind) || isRight(kind) || isFull(kind));
bool special_left = isInnerOrLeft(kind) && (is_any || is_semi);
return (all_join || special_left) && table_join->oneDisjunct();
}
MergeJoin::RightBlockInfo::RightBlockInfo(std::shared_ptr<Block> block_, size_t block_number_, size_t & skip_, RowBitmaps * bitmaps_)
: block(block_)
, block_number(block_number_)
, skip(skip_)
, bitmaps(bitmaps_)
{}
MergeJoin::RightBlockInfo::~RightBlockInfo()
{
if (used_bitmap)
bitmaps->applyOr(block_number, std::move(*used_bitmap));
}
void MergeJoin::RightBlockInfo::setUsed(size_t start, size_t length)
{
if (bitmaps)
{
if (!used_bitmap)
used_bitmap = std::make_unique<std::vector<bool>>(block->rows(), false);
for (size_t i = 0; i < length; ++i)
(*used_bitmap)[start + i] = true;
}
}
}